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QuickSim II User`s Manual

1. suppress_limit x_limit 0 aA gt tP 6 on Ato Y y tP 3 on B to Y Bo A B Y scheduled prior to t3 pl gt Y scheduled after t3 0 tt 2 B Figure 2 17 Spike with Previous Event Scheduled Scheduling with Multiple Spike Models For the unusual case where there are multiple spikes occurring on a pin and the widths of the various spikes occur in different regions the spike model of the last spike to occur will always be used even if this seems to override a previous spike model response For example an XOR gate with a spike model that specifies any output pulse less than 3 nsec should be X immediate and anything else should be transport as shown in Figure QuickSim II User s Manual V8 5_1 2 35 Spike Models Key Concepts tP 4 on A B to Y A i B AY B Y before time 4ns S rel Y after time 4ns r TIME t t 3 t 4 t 7 8 Figure 2 18 Scheduling Multiple Spike Models In this example the event on A at time t1 schedules Y to go to 1 at 4 nsec The event on B at 3 nsec schedules a transition to 0 at 7 nsec This creates a pulse on Y with a width of 3 nsec so the conflicting event is transported The second event on A at 4 nsec attempts to schedule a 1 on Y at 8 nsec except the output change would create a pulse of 1 nsec The X immediate response is chosen which cancels the two previously scheduled events
2. Reporting on Component Interfaces Determining Object Names Determining Object Names in Frames Using Buses Using Synonyms Assigning Synonyms Listing Synonyms Removing Synonyms Highlighting Instances Nets and Pins Displaying Design Information Reporting on the Selection 4 4 QuickSim II User s Manual V8 5_ 1 Operating Procedures Cross Index Design Viewpoint Editor Procedures Table 4 2 Operating Procedures that are found in the Design Viewing and Analysis Support Manual Reporting Properties of Selected Objects Displaying Design Information Listing Specific Information about cont Selected or Specific Objects Generating Part Lists Generating Part Lists Design Viewpoint Editor Procedures Table 4 3 Operating Procedures that are found in the Design Viewpoint Editor User s and Reference Manual Invoking DVE Opening and Closing a Design Viewpoint Editing a Design Viewpoint Setting Parameter Values Setting Primitiveness Setting Substitute Values Setting Visible Properties Exporting a Design Configuration Checking a Design Creating a DVE Script Back Annotating a Design Creating a Back Annotation Object Adding a Property Changing a Property Deleting a Property QuickSim II User s Manual V8 5_ 1 4 5 Design Viewpoint Editor Procedures Operating Procedures Cross Index Table 4 3 Operating
3. Changing A Property The simulator writes all property changes to a back annotation object By default the back annotation object with the highest priority receives all design property modifications To write the changes to a back annotation object other than the one that has the highest priority refer to Writing Property Changes to a Specific Back Annotation Object on page 3 80 To change the value of a property perform the following steps 1 Select the net pin or instance that owns the desired property 2 Choose the following pulldown menu path Menu Bar gt Edit gt Property gt Change The simulator displays the Change Properties dialog box which is shown in Figure 3 36 Change Properties Select property names to edit fall 10 rise 25 drive SSS ox Reset Cancel Figure 3 36 Change Properties Dialog Box The available properties and their respective values are displayed in a list box 3 Click the property whose value you wish to change 4 Click on the OK box to expand the dialog box When you OK the initial dialog box the simulator displays an expanded version which is shown in Figure 3 37 QuickSim II User s Manual V8 5_ 1 3 83 Changing the Design in QuickSim Il Operating Procedures Change Property fall on I 4 OUT Property Type Vv string A number BA Name user lulu_b sim_ba V expression UA triplet OK Reset Cancel Figure
4. Quicksim crashes with reset _ This page is under construction Don t be surprised by frequent changes as we continue our work A 28 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Quicksim crashes with initialize Quicksim crashes with initialize _ This page is under construction Don t be surprised by frequent changes as we continue our work QuickSim II User s Manual V8 5_1 A 29 Quicksim crashes on AMPLE execution QuickSim Il Troubleshooting Quicksim crashes on AMPLE execution _ This page is under construction Don t be surprised by frequent changes as we continue our work A 30 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Quicksim hangs during run Quicksim hangs during run _ This page is under construction Don t be surprised by frequent changes as we continue our work QuickSim II User s Manual V8 5_1 A 31 Quicksim hangs with command execution QuickSim Il Troubleshooting Quicksim hangs with command execution by frequent changes as we continue our work fe This page is under construction Don t be surprised A 32 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Quicksim hangs with AMPLE execution Quicksim hangs with AMPLE execution _ This page is under construction Don t be surprised by frequent changes as we continue our work
5. The user interface Setting up the user interface is common to all Mentor Graphics analysis applications It involves changing the SimView UI environment defaults and the window display formatting defaults For the procedures that describe how to set up the user interface refer to Setting Up SimView in the SimView Common Simulation User s Manual The kernel Setting up the kernel is unique to QuickSim II The kernel is what performs the actual simulation Kernel setups include simulation modes such as the timing constraint and spike modes and simulation checking capabilities such as spike and contention checking on either individual instances or the entire design Setting Up the Kernel You can set up the kernel to meet the needs of your particular simulation Kernel specific setup conditions include analysis conditions such as VHDL model controls and iteration limits timing mode spike model contention and constraint checking model generated messages and toggle checking Before setting up the kernel you should consider the contents of your design and where you are in the flow of simulation development Table 3 1 contains some typical conditions that suggest customizing the kernel setup If you identify any of the circumstances listed in the left most column you may want to perform the suggested setup action in the right most column 3 18 QuickSim II User s Manual V8 5_1 Operating Procedures Setting Up Quic
6. P3 PA 0 2 C P1 P2 B A 0 11 F P5 P6 2 20 D Figure 2 5 How the Simulator Sees the Schematic Based on the Figure 2 5 circuit Figure 2 6 illustrates how the simulator schedules the events that result when net A receives a force that changes its state from 0 to 1 at the simulation time of 1 nS This stimulus is provided through a Force command which causes QuickSim II to schedule an event in slot 10 of the timing wheel 2 16 QuickSim II User s Manual V8 5_1 Key Concepts How QuickSim Il Processes Circuit Activity Figure 2 6 shows another representation of a timing wheel Each slot equals the default timestep value of 0 1 nS 10 slots equal 1 nS The circles represent events that the simulator processes and the diamonds represent instances that simulator evaluates Included at the bottom of Figure 2 6 is a representative trace of nets A B C and D The following description is based on the circuit in Figure 2 5 QuickSim II User s Manual V8 5_1 2 17 How QuickSim II Processes Circuit Activity Key Concepts 0 Oj 1nS 1 Events 9 5 Pe 1 10 m E J 1 11 aa PT 2 i 19 Om R 2 20 ea p 21 E P3 Causes 4 Causes lt gt 9 5S A 4 40 5 gt Pa 41 j EN i Pun Timing 7 RA Wheel PS D C B A 0 1 2 3 4 5 2 18 TIME 0 QuickSim schedules the forced event F to occur in 1 nS slot 10 TIME
7. QuickSim II User s Manual V8 5_ 1 A 33 Quicksim runs out of memory during simulation run QuickSim II Troubleshooting Quicksim runs out of memory during simulation run by frequent changes as we continue our work fe This page is under construction Don t be surprised A 34 QuickSim II User s Manual V8 5_1 Appendix B Invocation of QuickSim II for FPGAstation Introduction A new station has been released FPGA Station that is targeted specifically at FPGA designers This stations includes the functionality and performance of Idea Station that is critical to FPGA designers This release contains a restricted version of QuickSim II known as QuickSim FPGA Description of Functionality With FPGA Station the QuickSim II kernel is modified to only recognize instances of components that reside in specific FPGA libraries VHDL models and generic library components Instances that reside in other libraries or custom hybrid models will be turned into NULL models QuickSim FPGA is invoked using the quicksim_fpga command which is described in the Digital Simulators Reference Manual All arguments and switches are identical to the current quicksim command the simulation will use the same qsim mod executable file The quicksim_fpga command is released with the standard QuickSim II package and does not require additional package modifications A new Design Manager tool icon has also been created for
8. fe This page is under construction Don t be surprised QuickSim II User s Manual V8 5_1 A 23 QuickSim Runs Out of Memory During Invoke QuickSim Il Troubleshooting QuickSim Runs Out of Memory During Invoke by frequent changes as we continue our work fe This page is under construction Don t be surprised A 24 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Symptom QuickSim Fails After Invocation Symptom QuickSim Fails After Invocation Quicksim crashes during run e Quicksim crashes with reload model Quicksim crashes with reset e Quicksim crashes with initialize e Quicksim crashes on AMPLE execution Quicksim hangs during run Quicksim hangs with command execution Quicksim hangs with AMPLE execution Quicksim runs out of memory during simulation run QuickSim II User s Manual V8 5_1 A 25 Quicksim crashes during run QuickSim Il Troubleshooting Quicksim crashes during run _ This page is under construction Don t be surprised by frequent changes as we continue our work A 26 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Quicksim crashes with reload model Quicksim crashes with reload model _ This page is under construction Don t be surprised by frequent changes as we continue our work QuickSim II User s Manual V8 5_1 A 27 Quicksim crashes with reset QuickSim Il Troubleshooting
9. For more information on how to set up and use Technology File configurable spike models refer to Spike Conditions in Technology Files in the Technology QuickSim II User s Manual V8 5_1 2 29 Spike Models Key Concepts File Development Manual For information on the Spike_model statement refer to SPIKE_MODEL in the Technology File Development Manual Netdelay Property Spike Model Incorporating the Spike_model into the Netdelay property is available because the Netdelay value is usually back annotated after layout By including the spike model in the property the spike_model can be annotated together with the delay when the spike duration is a function of the wire delay being modeled Here is an example of a Netdelay property value for an input with two drivers TS21 out 5 SPIKE MODEL 2 5 1 29 out 11 SPIKE MODEL 4 7 Here is another example of an input with one driver where triplet values and the X IMMEDIATE directive is specified a Netdelay property value for an input with two drivers TS411 out 4 SPIKE MODEL X_IMMEDIATE 2 3 4 4 5 6 Spike Model Simulation The operation of a pulse propagation spike model in QuickSim II can be demonstrated using a single output device as shown in Figure 2 12 wN IN eo OUT Figure 2 12 Single Output Device Spike Example At time 0 OUT is at some state state0 and no events are scheduled At time
10. Spike models instruct the simulator on how to handle a type of signal transitions known as spike conditions A spike condition is a violation that occurs when the simulator tries to schedule an event on a pin that has already an event scheduled The simulator can use two types of spike models the spike suppress model and the X immediate model For more information about how these spike models affect simulation results refer to Spike Models on page 2 24 You can set the spike model on any instance at any level in the design in addition to being able to set the spike model for the entire design when you invoke the simulator QuickSim II User s Manual V8 5_1 3 39 Changing the Spike Model Operating Procedures The following procedure describes how to set the spike model for one or more instances 1 Select the desired instance or instances You can verify that you have selected only the desired instances by looking at the highlighting in the displayed windows Although instance selection is not required it is generally easier than specifying names of instances in the dialog box created in the next step 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Spike Model The simulator displays the Change Spike Model dialog box which is shown in Figure 3 15 3 40 QuickSim II User s Manual V8 5_1 Operating Procedures Changing the Spike Model Change Spike Model On Sel
11. Timing mode unit Change Delay Scale 1 _ Override OK Reset Cancel Help Figure 3 6 Change Timing Mode Dialog Box 3 Click on the appropriate Timing mode button to choose the timing values you want to use 4 Click on the OK button The simulator calculates the timing information for the selected instance The timing mode and other setup conditions can affect instances that are hierarchically below the targeted instance The simulator also calculates the timing information for these lower level instances The Override button allows you to override similar settings at levels below the selected instance If an item is set with the Override button at a lower level in the design the propagating effect of a setting at a higher level is ended For more information about this hierarchical behavior refer to Effects of Hierarchical Commands in the Digital Simulators Reference Manual Initializing the Design Although QuickSim H automatically initializes your design at invocation you may want to change the global initialization value or type of initialization To initialize your design perform the following steps 3 24 QuickSim II User s Manual V8 5_1 Operating Procedures Setting Up QuickSim Il 1 Choose the following pulldown menu path Menu Bar gt Run gt Initialize The simulator then displays the Init prompt bar shown in Figure 3 7 xr Ini defaut INIT State Value Xr Init T
12. Waveform database procedures 4 2 Waveform databases Forces WDB 2 38 overview 2 37 Results WDB 2 37 Stimulus WDB 2 38 Waveforms loading procedure 4 2 WDB s procedures 4 2 Wildcards help 3 15 X X immediate spike model 2 25 X logic value 2 9 Z Z drive strength 2 9 QuickSim II User s Manual V8 5_1 Index 5 Index INDEX continued Index 6 QuickSim II User s Manual V8 5_1
13. tl IN changes and schedules OUT to go to a different statel with a delay d1 determined from the first propagation delay statement in the Technology File This is event1 tP 11 13 19 on IN AL to OUT AL SPIKE_MODEL low_pulse 2 30 QuickSim II User s Manual V8 5_1 Key Concepts Spike Models At time t2 IN changes again and the state of OUT is to be scheduled to some different state2 with delay d2 called event2 The pulse width t2 t1 is less than the delay d1 and a spike occurs In the examples below state2 will be the same as stateQ but this is not always true If an event is pending on an output pin and a new event is scheduled which matures before the pending event that pending event is canceled and the new event scheduled In this case event would be canceled if event2 were scheduled to mature before event1 In the diagrams discussed below the events mature in the order that they are scheduled These diagrams show the different effects on event and event2 depending on the spike_model and the region in which t2 occurs Note If the model has multiple paths to an output with differing spike models and the pending and new events appear at the output from different inputs the spike model of the new event will be used Pulse in the Suppress Region The spike is in the suppress region if the pulse width t2 t1 is less than the SUPPRESS_LIMIT parameter This occurs w
14. 3 51 QuickSim H accuracy 2 11 architecture 1 12 back annotation concepts 2 48 batch simulation procedure 3 11 capabilities summary of 1 3 data objects 2 5 delay modes 2 21 delays scaling 2 21 drive strengths 2 9 Electrical connectivity for 2 16 inertial 2 21 initialization process 2 39 input data 1 14 invoking procedure 3 6 key concepts 2 2 logic values 2 9 operating procedures 2 48 output data 1 14 reset procedure 3 65 Index 3 Index INDEX continued spike models 2 24 timing modes 2 19 transport delay mode 2 21 QuickSim Palette procedure 3 64 R Reference help procedure 4 1 Reloading models concepts 2 46 Reloading models procedure 3 78 Report Breakpoints command operating procedure 3 75 Reporting toggle statistics procedure 3 56 Resetting the simulator procedure 3 65 Resistive R drive strength 2 9 Restoring setups procedure 3 31 Restoring simulation states procedure 3 67 Results WDB 2 37 Results WDB and the keep list 3 60 Running the simulator 3 65 S Saving setups procedure 3 27 Saving simulation states procedure 3 67 Scheduling events 2 18 Schematic view procedure 4 6 Setting up instance by instance procedure 3 23 Setting up simulations 3 17 Setting up kernel 3 18 Setup groups 3 29 Setup procedure for saving 3 27 Setups procedure for restoring 3 31 Sharing annotations 4 6 Signal strength explanation of 2 9 Simulation manuals
15. Help Figure 3 29 Add Breakpoint Dialog Box 2 If you want to interrupt the simulation based on a simulation expression or signal state perform the following steps a Click on the Expression button b Enter a signal name or a simulation expression in the Expression entry box A signal name can be a pin net or bus design pathname a VHDL signal name a synonym or a user defined bus If you have a net or bus selected its name becomes the default entry in the Expression entry box For information about defining simulation expressions refer to Simulation Expressions in the SimView Common Simulation Reference Manual 3 72 QuickSim II User s Manual V8 5_1 Operating Procedures Using Breakpoints c To specify that the breakpoint occurs when the evaluation of the Expression entry changes click the On change button Note that if you specify a signal name in the Expression entry box you must click the On change button d To specify how many times the breakpoint conditions must occur before the simulation is interrupted enter a number in the On occurrence entry box e To evaluate the breakpoint at the completion of the timestep click on the End of timestep button If the End of timestep button is not highlighted the breakpoint is evaluated after the iteration in which the breakpoint occurs which is generally desirable when setting breakpoints on VHDL objects f To issue one or more function
16. Reference Help Reference help is information that is displayed using the BOLD Browser and the online INFORM documentation library The simulator offers the following primary categories of reference help e Tables of version 8 commands and functions e A map of logical key names e Palette information e The tutorial document The procedures documented in this manual e The combined index of the manuals in the simulation bookcase The bookcase associated with the QuickSim II application The primary method of accessing reference help is through the Help pulldown menu You can also click on the Ref Help button that is provided in many of the dialog boxes Setting Up QuickSim Il Once you have invoked the simulator you typically perform setup procedures to prepare for the simulation You have complete control over the simulator s setup through items in the menus QuickSim II User s Manual V8 5_1 3 17 Setting Up QuickSim Il Operating Procedures Setting up the simulator is optional you should set it up only if the default setup conditions are not acceptable to you You can set up three areas e The session Setting up the session is common to all Mentor Graphics applications Session setups include choosing the graphics input device double click speed session window characteristics and custom userware For detailed procedures that describe how to set up the session refer to Procedures in the Common User Interface Manual
17. Report gt Design Viewpoint 3 80 QuickSim II User s Manual V8 5_1 Operating Procedures Changing the Design in QuickSim Il The simulator creates a list of the back annotations that the design viewpoint references You can write to any of the listed objects 2 Click on the desired back annotation object to select it The simulator highlights the selected back annotation object 3 Make the desired property additions or modifications The simulator writes all subsequent property changes to the selected back annotation To write changes to a different back annotation object repeat this procedure and select the desired back annotation object For concept information about back annotation objects refer to Back Annotation Objects and QuickSim I on page 2 48 Swapping A Model Swapping a model involves changing a design property but special userware eases identifying and specifying the desired model Because you are changing a property the modification is written to the targeted back annotation object To swap a model perform the following steps 1 Select an instance Only one instance is allowed for each swap 2 Choose the following pulldown menu path Menu Bar gt Edit gt Model The simulator displays the Change Model dialog box which is similar to the one shown in Figure 3 35 QuickSim II User s Manual V8 5_ 1 3 81 Changing the Design in QuickSim Il Operating Procedures Change Model on instance
18. defaults 3 5 Model property procedure for changing 3 81 QuickSim II User s Manual V8 5_1 Index INDEX continued Model types 2 4 Modeling manuals list of titles xvi Models change procedure 3 81 changing Model properties concepts 2 47 functional 2 3 overview 2 4 reloading concepts 2 46 reloading procedure 3 78 swapping concepts 2 47 swapping procedure 3 81 timing attributes of 2 13 types 2 4 N Node contention how to resolve 2 12 Non connectivity changes 2 44 O Online helps using 3 15 Open sheet 4 6 Operating procedures 2 48 Operating procedures cross index 3 84 Output data QuickSim II 1 14 P Palette QuickSim procedure 3 64 Palettes procedure 4 1 Pattern matching see Command completion Pins Events on 2 18 Popup command bar procedure 4 1 Popup menus procedure 4 1 Primitives default 3 5 Procedures common simulation interface 4 1 cross index 3 84 Design Viewing and Analysis Support 4 1 Design Viewpoint Editor 4 3 QuickSim II User s Manual V8 5_1 DVAS 4 1 Prompt bars procedure 4 1 Properties changing Model concepts 2 47 changing Model procedure 3 81 changing concepts 2 47 changing effects of 2 43 changing procedure 3 83 default 3 5 simulation 2 9 Property change procedure 3 83 Pulldown menus procedure 4 1 Q Querying for commands see Command completion Quick help procedure 4 1 QuickPart messages procedure for displaying
19. gt Kernel gt Change gt Model Messages The simulator displays the Change Model Messages dialog box which is shown in Figure 3 20 QuickSim II User s Manual V8 5_1 3 51 Reporting Model Statistics Operating Procedures Change Model Messages On Selected instances Named instances Messages A oft _ Override son OK Reset Cancel Help Figure 3 20 Change Model Messages Dialog Box 3 Make the appropriate choices from the dialog box as follows a Choose either the Selected instances button or the Named instances button from the top of the dialog box If you choose the Named instances button you must also complete the Instance name entry box b Click the On button to enable the display of model generated messages c To override the model message settings at levels below the selected or specified instances click on the Override button Note that this button will not override lower level model message settings that were also set with the Override button 4 Click the OK button to activate your choices Reporting Model Statistics A command available in the V8 5_1 Report Model Statistics allows you to report information about the models used in a design or for a specified hierarchical instance This command reports the following 3 52 QuickSim II User s Manual V8 5_1 Operating Procedures Reporting Model Statistics the number of instances of each model type e for each model ty
20. list of titles xvi Simulation states procedure for saving 3 67 Simulator reset procedure 3 65 Spike model procedure for changing 3 39 Spikes procedure for checking 3 42 Index 4 Stability checking procedure 3 58 State values accuracy of 2 11 State values explanation of 2 9 States save and restore procedures 3 67 Stimulus WDB 2 38 Stimulus applying 3 62 Stimulus procedures 4 2 Stimulus saving procedure 4 2 Strengths of signals 2 9 Strong S drive strength 2 9 Suppress spike model 2 25 Suspending the simulation 3 13 Swapping models concepts 2 47 Swapping models procedure 3 81 Synchronous designs checking stability of 3 58 T Time viewing current simulation 3 65 Timestep and simulator accuracy 2 12 Timing Accuracy of 2 12 Attributes of models 2 13 Delays and scheduling 2 18 Model attributes for 2 13 Timing modes concept 2 19 Timing modes procedure for setting 3 33 Timing wheel algorithm 2 15 Timing wheel example of 2 15 Toggle statistics procedure 3 56 Toggle statistics procedure for gathering 3 54 tPX transition effects on spikes 2 26 Transport delay mode 2 21 Troubleshooting breakpoints using 3 71 U Update model procedure 3 78 QuickSim II User s Manual V8 5_1 Index INDEX continued Vv Variables Environment C 1 VHDL view procedure 4 6 Viewpoints customizing 3 3 Views schematic procedure 4 6 VHDL procedure 4 6 W
21. x_limit 7 lt gt d1 13 q gt IN event scheduled at time t1 d1 Spike event1 changed to X pulse state event2 scheduled for time t2 d2 OUT 7 AES P 0 t1 t2 Figure 2 14 X pulse Region suppress_limit lt t2 t1 lt x_limit X immediate specified When an X immediate spike occurs the pending event is canceled and the output is immediately set to the X pulse state The new event is then scheduled with delay d2 The output changes from state0 to the X pulse state at time t2 and then to state2 at time t2 d2 This behavior is shown in Figure 2 15 suppress limit 4 lt gt x_limit 7 lt gt d1 13 a IN event scheduled at time t1 d1 Spike event1 cancelled OUT goes immediately to X pulse state A SLEX SLLIS OUT RS BS gt T i rece Sees Zee 0 t1 t2 event2 scheduled for time t2 d2 Figure 2 15 Pulse in X pulse Region X immediate is Specified QuickSim II User s Manual V8 5_1 2 33 Spike Models Key Concepts Pulse in the Transport Region The spike is in the transport region if the pulse width t2 t1 is greater than X_LIMIT but still less than the total path delay d1 This is where the pulse width of the spike is wide enough that the output can reach the intermediate state state1 in this example before going to the new state state2 Assuming that event2 is scheduled to occur after event1 the spike pulse is transpor
22. 1 What is Simulation Overview of QuickSim Il in the design process you typically focus on analyzing and debugging high level functional models As you develop the detailed description of your design you can use the modeling method that best suits your objectives and still use the same simulator The attributes of a practical digital logic simulator are accuracy efficiency and comprehensiveness Accuracy means a close correspondence between simulated signal values over time and the behavior of the physical design Efficiency refers to workstation memory requirements and simulation speed Comprehensiveness refers to the degree to which the simulator manages a broad class of digital designs independent of device technologies A simulator should manage the many types of bipolar and MOS designs including the following e Standard digital logic configurations such as the following o Combinational circuits logic networks with no storage capability o Synchronous circuits any clocked device o Asynchronous circuits any unclocked sequential circuit with feedback e A wide selection of model types such as the following o Switch level transistor models unidirectional and bidirectional o Gate level models AND NAND OR and so on o Sequential models latches and registers o Functional models compiled from gate level or state table models o Special models ROMs RAMs PLAs PLDs one shots and multi vibrators o VHDL m
23. 1 88 I 62 I 43 Select a model Model Name Model Type label1 labeln schematic mgc_schematic schema cyclops_alu_b Qpb_g5_model G5 BA Name DESIGNS cyclops alu default OK Reset Cancel Figure 3 35 Change Model Dialog Box The available models are displayed in a scrolling window and you can click on one to select it Each line contains three fields o Model name The name given to the model when it was created and the first field on each line in the list box In Figure 3 35 the model names are schematic and cyclops_alu_b o Model type The type of model such as schematic or VHDL and is the second field on each line in the list box In 3 35 the model types are mgc_schematic and Qpb_g5_model o Model labels The labels that are registered with the model and is the third field on each line in the list box In Figure 3 35 the model labels are schematic and G5 If more than one label is registered to the model the simulator uses the first label in the field 3 Click on the model you wish bring into the simulation 4 Click on the OK button For more information about swapping models see the Swapping Models on page 2 47 For information about the Change Model command refer to Design Viewpoint Editor User s and Reference Manual 3 82 QuickSim II User s Manual V8 5_1 Operating Procedures Changing the Design in QuickSim Il
24. 2 3 ON clk LH TO q WITH clr L amp set L Any of the following SDF statement will be considered a match 1 COND clr amp set IOPATH posedge clk q 1 2 3 2 COND clr IOPATH posedge clk q 1 2 3 3 COND set amp foo clr IOPATH posedge clk q 1 2 3 4 COND foo amp bar IOPATH posedge clk q 1 2 3 5 IOPATH posedge clk q 1 2 3 In the examples above the top statement matches best and would be used The second statement covers the CLR L while the third covers SET L If these two statement both occur statement 2 will annotate the Technology File statement shown as 3 contradicts the CLR L condition Statements 4 and 5 do not cover any conditions in the WITH expression and are an inferior fit for the Technology File but will be allowed to annotate if no better statement such as any of the first three is found If both 4 and 5 occurred in an SDF CELL 5 will prevail as it is a more general statement Equality operators The SDF binary operators and are mapped to the new in this QuickSim II release AMP system function SIM_ CMP lt signal1 gt lt signal2 gt Inequality operators and will map to the NOT operator followed by the comparison operator ISIM_ CMP lt signal1 gt lt signal2 gt Note that AMP does not allow nesting expressions within Sim_ cmp arguments So expressions such as A B C will be ignored when mapping
25. 3 14 Change Constraint Mode On Selected instances Named instances Constraint mode A off Vv State only _ Override M y Messages OK Reset Cancel Help Figure 3 14 Change Constraint Mode Dialog Box 3 Make the appropriate choices from the dialog box as follows a Choose either the Selected instances button or the Named instances button from the top of the dialog box 3 38 QuickSim II User s Manual V8 5_1 Operating Procedures Changing the Spike Model If you choose the Named instances button you must also complete the Instance name entry box b Click on the appropriate Constraint mode button e Off Disables constraint checking Default upon invoking the simulator State only Enables checking the timing constraints that can set the state of the model s output pins when a violation occurs In this mode no constraint violation messages are displayed Messages Checks for all constraint violations and displays appropriate messages when violations occur This mode also checks for constraints that can affect the state of output pins c To override the constraint modes set at levels below the selected or specified instances click on the Override button Note that this button will not override lower level constraint modes that were also set with the Override button 4 Activate your choices by clicking the OK button at the bottom of the dialog box Changing the Spike Model
26. 3 37 Expanded Change Property Dialog Box This dialog box displays the property being changed in the window title the design item being affected and current property value 5 Enter a new property value in the Value entry box 6 Click on the appropriate Property Type button to specify the type of the value 7 Specify the path to the back annotation object to accept the change If you do not specify a back annotation object path the annotation will be placed in the highest priority back annotation 8 Click on the OK button For more information about changing property values see Changing Properties on page 2 47 For information about the Change Property command refer to Design Viewpoint Editor User s and Reference Manual 3 84 QuickSim II User s Manual V8 5_1 Chapter 4 Operating Procedures Cross Index This chapter contains lists of procedures that are documented in manuals related to QuickSim II Each item in each list is a hyperlink to the information that describes the procedure If you are reading this from within the BOLD Browser you can travel to the desired location by clicking on the hyperlink Common Simulation Interface Procedures Table 4 1 Operating Procedures in the SimView Common Simulation User s Manual Entering Commands Using Palettes Using Pulldown Menus Using Popup Menus Using Popup Command Bars Using Dialog Boxes Using Prompt Bars Accessing Hel
27. 5_ 1 Operating Procedures Exiting and Suspending the Simulator 2 Enter the commands and functions you want the simulator to execute 3 Terminate and submit the here document for execution by entering an exclamation point on line by itself The following lines show what an entire here document might look like SMGC_HOME bin quicksim my_batch_design nodisplay lt lt ADD Lists clock clear b c d out x1 x2 x3 x4 RUN 200 Absolute DOFile batch_forces do LOAd WDb good_waveforms Viewpoint CONnect WDb good_waveforms 3000 Absolute Merge RUN 190000 Absolute SAVe WDb my_batch_results results Replace Sset_active_window List WRIte REport batch_list 3000 19000 Replace Highlight Note that you could also place the lines of the here document into a file and then you could issue the here document simply by entering the filename at the shell command line Exiting and Suspending the Simulator Generally you need not exit the simulator unless you are ready either to simulate another design or to log off When you do need to exit the simulator you can do so in either of two ways e Using the window menu button which appears in the top left corner of the session window choose the Close menu item In some window systems this may be the Quit menu item Issue the Exit command from within the simulator QuickSim II User s Manual V8 5_1 3 13 Exiting and Suspending
28. Change Spike Warnings in the Digital Simulators Reference Manual Waveform Databases Waveform databases are compiled objects that the simulator uses for storing simulation stimulus and results and they are designed to contain manage and save one or more waveforms A waveform is a binary time ordered sequence of values or events that has a name Generally the waveform name relates to an object in a design to which it can be connected The simulator directly interacts with waveform databases when it either reads stimulus or writes results Because it interacts only with waveform databases the simulator translates all other forms of stimulus such as Force commands force files logfiles and MISL files to waveform database format before they are used Waveform databases have the following characteristics e They are a compiled form of the values that are associated with a signal This binary format is a particularly fast form of stimulus e The simulator automatically creates and manages some waveform databases because they serve special purposes but you can also create your own The special purpose waveform databases are as follows Results waveform database This waveform database contains the signal data that the simulator displays in windows It also stores the signal values that the simulator uses to evaluate expressions and breakpoints QuickSim II User s Manual V8 5_1 2 37 Waveform Databases Key Concepts 2
29. DIVIDER field and may be either or as defined in the SDF V2 0 syntax If is used SDF in translates it to a for use in the EDDM pathname The backslash VP character can be used to escape release special characters such as the dollar sign commonly used in EDDM instance names QuickSim II User s Manual V8 5_1 D 7 SDF Technology File Correlation SDF in QuickSim Il The AMP Timing Model The AMP timing model for an instance in a design is defined as the pin delays and an optional Technology file The AMP timing model acts as the template for the instance s timing shell which is the actual instance specific runtime structure in QuickSim II This means that all instances that use a given timing model have the same delay arcs and timing checks from an SDF file then timing values in Technology Files and pin Note properties can be some simple default value either a real number or a simple equation that estimates timing good enough for pre layout logic verification This greatly reduces the effort TimeBase spends creating the timing cache i If the modeler knows that post layout timing data for design comes SDF CELL Templates Since an SDF file is machine generated SDF in can take advantage of instances of a common cell type that use a common template to generate the SDF statements for each occurrence in the file When parsing an SDF file an SDF DELAY or TIMINGCHECK statement in a CELL is map
30. Driven contention pair if you want to specify a specific contention that is not specified by the above buttons Notice from the examples in the dialog box that wildcards any value and wildcards any strength If you use this entry the Model type is ignored You can specify more than one driven pair 4 Activate your choices by clicking the OK button If you save the design viewpoint you can keep the contention models that you set so the next time you invoke the simulator you don t have to add them again QuickSim II User s Manual V8 5_1 3 47 Checking for Contention Operating Procedures After you set the contention models for the simulation you must enable contention checking before running the simulation which is described next Checking for Contention Contention occurs when more than one pin is driving a given net You check for contention by setting the contention model on buses nets or the root design and then enabling contention checking If the simulator finds that a contention condition exists it generates an error message citing the pins that are responsible and the net where it occurred Only logic values can cause a contention condition For information about the contention models and how to set them refer to page 3 44 When you invoke the simulator you can enable contention checking for the entire design If you want to change this global setting you can enable or disable contention checking o
31. During Invoke QuickSim fails to produce a graphics window Quicksim II Hangs During Invocation QuickSim appears to invoke but it never gain control of the application QuickSim Crash During Invoke with the Fault Recovery Window QuickSim begins to invoke but fails with the Fault Recovery dialog box e Symptom Memory Fault QuickSim starts to create the application graphics window then fails with a memory fault message e Error Messages Issued QuickSim produces error messages during invocation but does not crash QuickSim Issues Warning Message on Invoke QuickSim produces warning messages during invocation but does not crash QuickSim NULLs Model on Invoke QuickSim produces messages during invocation that models are nulled QuickSim Loads Wrong Models on Invoke QuickSim loads the wrong schematic or models during invocation QuickSim Runs Out of Memory During Invoke QuickSim crashes during invocation with messages reporting Out of Memory A 2 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting QuickSim Crash During Invoke QuickSim Crash During Invoke QuickSim Crashes During Invoke with Reference to Id so These are typically crashes related to the use of Logic Modeling libraries QuickSim Crashes During Invoke with Reference to __cb_bt This is error message does not have a specific meaning as to the cause of the failure QuickSim Crashes During Invoke
32. Invoke the simulator with the Nodisplay switch and submit the dofile as redirected input The following example command line shows how to submit a dofile using redirected input SMGC_HOME bin quicksim my_design NODisplay lt my_dofile In this example the simulator executes all the functions and commands in the file my_dofile without displaying the graphical interface After it executes the dofile the simulator automatically returns control to the operating system shell Using Here Documents The other approach to batch simulation is to create a here document which is a set command lines that invoke and run the simulator at the shell level When you enter the command lines you use special characters on the first and last lines which tell the operating system that you are defining a here document A typical here document invokes the simulator submits commands and functions for the simulator to execute and then quits to return control to the operating system shell The following procedure describes how to use a here document for a batch simulation 1 3 12 At the shell enter a command line that contains the quicksim command followed by the special characters lt lt The following is an example that defines the beginning of a here document Notice that the command line includes the Nodisplay switch SMGC_HOME bin quicksim my_batch_design nodisplay lt lt QuickSim II User s Manual V8
33. Non connectivity changes that is property changes that do not change the structure of the circuit are allowed but do not initiate recalculation of timing data This includes changing such timing related properties as RISE FALL and NETDELAY all of which can be annotated by SDF When the timing cache is locked changes to these properties are ignored The MODELFILE property used to load memory models can be edited without changing timing and is legal after SDF annotation e Additional timing annotations via the Load SDF File command are accepted even when the timing cache is locked This is the proper way to incrementally change timing if SDF in has been used to load timing data The UNLOCK TIMING CACHE Command Users who wish to circumvent the rules outlined above may unlock the timing cache by issuing the UNLOCK TIMING CACHE command in QuickSim II If this is done subsequent invocations of TimeBase or QuickSim II will recalculate timing for any instance in the design SDF data may be lost since the timing cache lock for SDF annotation has been removed QuickSim II User s Manual V8 5_1 D 5 Annotating Specific Timing Modes SDF in QuickSim Il Changes between QuickSim Il Sessions If a locked timing cache is made persistent the lock is persistent as well But changes to the design that occur between QuickSim II sessions often invalidate an existing timing cache forcing its reconstruction and re annotation This can occur regardl
34. Selection which begins on page 2 6 Changing Properties Changing properties allows you to rapidly perform what if simulations Examples of typical properties that you can change include the Rise and Fall properties for adjusting delays physical properties such as the Cap_net or Temperature properties which may affect technology file constraints and timing and properties that affect design parameters such as a parameter that defines bus width Annotated property changes are highlighted on the schematic in red on color monitors and they can be either shown or hidden By default the simulator writes all property changes in the top priority back annotation object however you can direct specific property changes into any back annotation object that the design viewpoint references Back annotation objects are design data objects that hold design property changes and are associated with the design viewpoint The next section describes how the simulator interacts with back annotation objects QuickSim II User s Manual V8 5_1 2 47 Design Changes in QuickSim Il Key Concepts Back Annotation Objects and QuickSim Il QuickSim II is one of the applications that can create and use back annotation objects During a simulation the simulator reads the property changes from all the back annotation objects that the design viewpoint references When multiple back annotations are attached to a design viewpoint they are assigned p
35. Technology File edge receives the greater of the first two data fields in the SDF statement 2 in this case Two Value Data Fields A two rvalue data field is handled much like the three rvalue field above though its definition differs somewhat The first field is for 01 OZ Z1 transitions and the second for 10 1Z ZO The twelve to six mapping occurs first If one of the first two fields are still not indicated the six to two transition below occurs roy 01 10 0Z Z1 1Z 20 Figure D 4 Six to Two Rvalue Transform A Single Data Field Finally if only a single data field is found it is used for all output transitions found in the Technology File QuickSim II User s Manual V8 5_1 D 23 SDF Technology File Correlation SDF in QuickSim Il D 24 QuickSim II User s Manual V8 5_1 Index INDEX 12 State simulation explanation of 2 9 A Add Breakpoint command troubleshooting 3 71 Architecture QuickSim II 1 12 B Back annotation concepts 2 48 concepts in QuickSim II 2 42 Sharing procedure 4 6 Batch simulation 3 11 Breakpoints deleting 3 76 reporting 3 75 using 3 71 C Change model procedure 3 83 Changing contention models procedure 3 44 Changing properties procedure 3 83 Changing spike models procedure 3 39 Checking for contention procedure 3 48 Checking for hazards procedure 3 49 Checking for spikes procedure 3 42 Checking procedures device stabi
36. are created by layout tools such as Quad Tool s Crosstalk Network Simulator XNS or Transmission Line Calculator TLC These tools generate a file of delay information with the suffix idd QuickSim II allows you to load this delay information into a back annotation object and then import these back annotations into your design using the Load Net Delay command For information on this command refer to the Load Net Delays section of the Digital Simulators Reference Manual For information on 2 48 QuickSim II User s Manual V8 5_1 Key Concepts Design Changes in QuickSim Il the structure of an IDD file refer to the Net Delay File Format Requirements section in the Digital Simulators Reference Manual EDDM Bundle Functionality QuickSim II supports the EDDM bundle functionality implemented at Release B 1 A bundle refers to a collection of nets or pins The following list is a brief set of definitions that apply to bundles e A NetBundle is a collection of nets netbundles and buses e A PinBundle is a collection of individual pins pinbundles and wide pins The bundle name must be unique that is it cannot be named the same as an object it contains e An object may appear more than once in a bundle e A NetBundle can connect to a PinBundle or a wide pin This connection is made by position You use bundles to easily manipulate signals that are related QuickSim II recognizes bundles in expressions
37. be used when you simulate a design that contains or consists of System 1076 models The following procedure describes the process of default initialization 1 The simulator sets the initial state of all pins and nets according to the Initialize command if specified If the initialization is caused by the Reset State command or it is an invoke time initialization the simulator sets all pins and nets to the default state of XR 2 The simulator sets the state of all nets according to any associated Init properties The net Init property values which you specify during design creation or back annotation override any values set in the previous step 2 40 QuickSim II User s Manual V8 5_1 Key Concepts QuickSim II Initialization Process 3 The simulator evaluates all instances once using the states set in steps 1 and 2 and then schedules output events according to any associated delays both pin delays and technology file propagation delays N Unevaluated events exist at the end of a default initialization iy Because these events might affect your simulation you should run Note the simulator for a short period of time before applying stimulus for example Run 1000 Classic Initialization The classic initialization scheme which is compatible with previous versions of the simulator sets all delays to zero and then simulates the design until the circuit reaches a stable state has no pending events You can perform this
38. common among two or more simulators such as viewpoint creation and charting capability e Modeling Manuals page xvi these document the methodologies available to create models for Mentor Graphics simulation applications e Framework Manuals page xvii these document features that are common to all Mentor Graphics applications Figure on page xv shows which manuals document the various Mentor Graphics simulation products To use this figure locate the icon for your application across the top row and then descend along the shaded bar This bar overlaps each document title box that contains information about your application For more information about manuals listed in Figure 1 refer to the following pages If you are reading this manual online in the Bold Browser you can click the Select mouse button on the title boxes in Figure 1 to open that document You can also click on an application icon in the top row to open the Getting Started workbook for that application If you are unfamiliar with general Mentor Graphics documentation conventions or need to know how to write a command or a function you should first read Mentor Graphics Corporation Documentation Conventions xiv QuickSim II User s Manual V8 5_1 About This Manual Related Publications Sim View Analog Simulators User s Manual AL AAAA iD QuickSim IT Continuum AccuSim IT Getting Continuum User
39. each one Forces waveform database This unique waveform database contains waveform data that can be created or modified by the Force command You can load any waveform database from the disk into the Forces waveform database To edit a waveform it must first reside in the Forces waveform database By default the Forces waveform database is connected to the kernel although it can be disconnected e Waveform databases can be merged If you create several waveform databases to use as stimulus and want to subsequently merge them into one waveform database you load them into memory and connect them to the Stimulus waveform database You can specify time offsets to shift the point in time at which the waveforms are applied QuickSim II User s Manual V8 5_ 1 Key Concepts QuickSim II Initialization Process e Waveform databases can be viewed and edited within the simulator To view the contents of a waveform database you load it into memory and then add the desired waveforms to the Trace List or Monitor windows To edit a waveform database you must first load it into the Forces waveform database Then you either issue Force and Delete Force commands or use the icons in the Waveform Editor palette to add or change the desired waveforms You can view the changes if the waveform is in the Trace or List window e Any waveform database can be the default waveform database When the simulator displays signal activity evaluates
40. from Z to 1 or X to 1 use the second statement AH since the first statement is not active And all other Q transitions fall through to the third AA statement since no other transitions activate the first two statements In order to support Technology File s order of appearance priority for assigning timing values the SDF edge mapping template supports the notion of subordination to prior Technology File edges which differ only in their output transition specification as above The effect of subordination will be to turn off looking for data in an rvalue which is already covered by a superior Technology File edge So mapping of these Technology File statements to the single SDF statement goes as follows 1 SDF data is directed from the 01 first column to the first Technology File edge as usual It gets the value 12 2 Data for the second Technology File edge would normally be the greatest of columns 01 Z1 and X1 1 4 and 8 but since it has subordinated its interest in the 01 column to the preceding edge it will only compare data from Z1 and X1 and use the value 9 This is a valid decision because when the QuickSim II User s Manual V8 5_1 D 21 SDF Technology File Correlation SDF in QuickSim Il second edge is active it is only actually used when the first edge is not active so the transition cannot have been 01 3 Finally the catch all third statement will take the longest delay not covered by the previo
41. functions Logfile An ASCII file that the simulator produces Logfiles are useful with designs that are partitioned Typically you use a logfile to collect the simulation results from the output signals of one design partition Then you can use the logfile as stimulus for the input signals of the partition connected to the first partition Before using a logfile in a simulation you must first compile it using the Load Log command MISL file A file that contains the compiled statements from the Mentor Interactive Stimulus Language MISL Waveform database A compiled form of signal activity that the simulator generates The simulator converts all forms of stimulus into a waveform database before it actually uses the data to schedule the force events Using a waveform database for stimulus is similar to using a logfile because it QuickSim II User s Manual V8 5_ 1 Operating Procedures Applying Stimulus to a Simulation works best with partitioned designs You can use more than one stimulus waveform database at any time during a simulation and that you can interactively edit these databases during a simulation Waveform databases are described in Waveform Databases which begins on page 2 37 The simulator converts all forms of stimulus into a waveform database before actually scheduling the stimulus events The simulator deals directly with the waveform database Once the simulator creates a waveform database you can make it
42. functions and operations that deal with signals For more information on bundle specifications refer to the Design Capture Concepts section in the Design Architect User s Manual Hierarchical Pin Keep Functionality For the B 1 release support has been added to allow keeps of selected hierarchical pins This means that you are not required to type long hierarchical paths with suffixes such as PIN OUT When a hierarchical pin is kept for example via the Add Trace or Add List command using selection QuickSim II will create a waveform in the waveform QuickSim II User s Manual V8 5_1 2 49 SDF in QuickSim Il Key Concepts database with the name lt pin_name gt PIN The PIN suffix is added to ensure that there are no name collisions with the net connected to the pin m7 No IN or OUT suffix is appended because commands like Add Lists or Add Traces on selected pins look for the waveform without the Note IN OUT extension QuickSim II determines the pin direction by examining the pintype property on the hierarchical pin If a pintype of IN or OUT is found QuickSim II creates a waveform with the corresponding direction If a pintype of INOUT is found QuickSim IT creates a waveform of type OUT If any other pintype or no pintype is found the pin direction will default to out Note that when keeping bi directional pins via selection since QuickSim II creates a waveform with the pin direction of OUT you must exp
43. in SIM UI The menu path for this operation is File gt Load gt SDF File For more information on using this operation refer to Loading an SDF File on page 3 36 Importing an SDF file Using TimeBase You may alternately annotate timing data while running TimeBase in stand alone mode This is especially useful when more than one timing mode is to be annotated This load process uses the importsdf switch for the Timebase command For information on loading an SDF file using the Timebase command refer to Importing an SDF File in TimeBase in the Technology File Development Manual QuickSim II User s Manual V8 5_1 2 51 SDF in QuickSim Il Key Concepts 2 52 QuickSim II User s Manual V8 5_1 Chapter 3 Operating Procedures This chapter explains common tasks associated with logic simulation It is organized sequentially by phases of the simulation process In INFORM you can click on the procedure name or page number below to access the procedure Processing a Design For Simulation 33 Invoking QuickSim II 3 6 Invoking from the Design Manager 3 6 Invoking from A Shell 3 10 Running a Batch Simulation 3 T Using Redirected Input 3 lI Using Here Documents 3 12 Exiting and Suspending the Simulator 3 83 Using the Online Helps __ _E 8 15 Command Completion 315 Quick Help 3 16 Reference Help 3 17 Setting Up QuickSim HU 3 17 Setting Up the Kernel _ _ 3 18 Setting Up Insta
44. maintained for analysis later QuickSim II User s Manual V8 5_ 1 Overview of QuickSim Il QuickSim Il Overview You may want to establish a persistent version of your design which you can do by latching the design viewpoint A latched viewpoint maintains a specific version of your design and all the objects it references which allows you to simulate your design without dealing with incremental changes until you are ready You might also import ASCII back annotation data to adjust the timing values that the simulator calculates b Generate and refine stimulus Stimulus is input data that the simulator uses to exercise the design QuickSim II supports several methods for creating and refining stimulus such as commands functions graphical waveform editor logfiles and the Mentor Interactive Stimulus Language MISL All methods result in an efficient compiled form called a waveform database which you can manipulate edit save and delete c Run the simulation You can optimize the simulator to either run fast or produce highly accurate results Speed is important for early debug analysis On the other hand you can request a high level of accuracy to verify the design before going into manufacturing d Analyze the results of the simulation You can use several types of display windows to help you debug your design For example graphical schematic displays help you view and traverse the hierarchy of your design waveform trace d
45. modes unit delay linear timing linear timing with constraint checking full timing and full timing with constraint checking Note that you do not typically use every timing mode Except for the unit delay timing mode you can choose from minimum typical or maximum delay values Each mode consists of various settings that make speed and accuracy trade offs You can increase simulation accuracy as your design matures In general the higher the simulation accuracy the slower the simulation You can use switches to set the timing mode for the entire design when you invoke the simulator or you can use individual commands once the simulator is invoked You can also set the timing mode on individual instances if you want to customize your simulation in a more detailed manner The different timing modes are shown in Figure 2 7 and each mode is described in the list that follows The height of each block represents the relative burden on the simulator Actual simulator performance may vary for individual circuits Linear Timing if present Checking Unit Delay Full Timing with jam Full Constraint m Timing Checking i z 3 U Simulation Accuracy _ Figure 2 7 Timing Mode Comparison QuickSim II User s Manual V8 5_1 2 19 Simulation Timing Modes Key Concepts The five timing modes are as follows Unit delay timing Provides high run time and invoke time perform
46. not override lower level stability checking that was also set with the Override button 4 Activate your choices by clicking the OK button Keeping Circuit Activity All circuit activity that the simulator needs for display or analysis reasons is in the Results waveform database The keep list contains the name of each signal whose activity is being stored in the Results waveform database The following actions pertain to keeping circuit activity e To add signals to the keep list you can do so in either of two fundamental ways o Explicitly by using either the Add Keeps command or menu item o Implicitly by monitoring the signal through any of the following actions o Adding it to the Trace List or Monitor windows o Placing a monitor flag on the object o Using it in an expression or a breakpoint 3 60 QuickSim II User s Manual V8 5_1 Operating Procedures Keeping Circuit Activity In all of these cases the Results waveform database contains the simulated states of the associated net If you use the Add Keeps command with the Full switch the Results waveform database contains pin states net states and force states for the specified signals When adding keeps information you can specify nets pins or instances If you specify one or more instances all nets beneath the instances are kept Although this hierarchical behavior can aid in debugging portions of your design it can also keep more information which can s
47. persistent that is you can make it permanently available for future simulation sessions by registering it with the design configuration If you reset the simulation to time zero the simulator maintains the existing stimulus and automatically prepares it for the next simulation run For more information about using stimulus refer to Manipulating Stimulus in the SimView Common Simulation User s Manual QuickSim II User s Manual V8 5_ 1 3 63 Using the Palettes Operating Procedures Using the Palettes QuickSim II provides eight palettes which are sets of task oriented icons and buttons that you can click on to perform the associated task As an example the Setup palette is shown in Figure 3 25 Setup Palette Selection Buttons Common Command Buttons Palette Icons Figure 3 25 Setup Palette Each palette contains three sections as follows 8 palette selection buttons 8 common command buttons and a varied number of palette icons Although each palette has its unique set of icons the buttons appear unchanged in every palette To display the set of icons associated with a specific palette click on the desired palette selection button 3 64 QuickSim II User s Manual V8 5_1 Operating Procedures Running the Simulator To perform one of the common commands click on the desired common command button To perform the task assoc
48. remains in the keep list until you explicitly delete it For more information about deleting signals from the keeps list refer to Deleting Keeps in the SimView Common Simulation Reference Manual QuickSim II User s Manual V8 5_1 3 61 Applying Stimulus to a Simulation Operating Procedures When you delete a signal from the keep list all of that signal s data is deleted from the Results waveform database and from any window that used the data in the Results waveform database Applying Stimulus to a Simulation Once you have invoked the simulator and have set up the session and the kernel you generally apply stimulus to the inputs of the circuit You can force or apply stimulus to any net in the design When you do the simulator schedules a force event using the logic state signal strength and time you provide Force commands or functions The most common form of stimulus which is also available as a menu item Force commands are interactive and flexible Before issuing the Run command to start the simulation you apply a Force command to each net requiring stimulus Force file A macro that contains Force commands and or functions that you can submit as a batch of stimulus Force files are useful once you have determined and verified a set of Force commands Caution If your forcefile contains AMPLE functions to issues forces you must specify the forces as Force functions since Force commands do not execute within AMPLE
49. results Rather than changing the design and reloading the entire design you decide that you want to remove a certain part or parts from the simulation to isolate a specific timing path or paths To do this you must follow these steps 1 Open down to the primitive level of the component that you wish to remove 2 Select the component and change the model property value to null For example suppose that the component was a QuickPart Table Model It would have a model property with a value of QPT To null this model you would change property model QPT to property model null A null model will not be evaluated by the QuickSim kernel It is treated as an open connection at the inputs and outputs of the device NOTE If you are using an LM Hardware model QuickSim will crash if you try to null the model during a QuickSim session To null a LM Hardware Model you must change the model property in DA and reinvoke QuickSim on the design This problem for the LM Hardware Model will be corrected in Mentor Graphics A 1 F release V8 4 lt PRE gt A 12 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Signal 10 Recovery Signal 10 Recovery Signal 10 errors are generally related to corruption of the QuickSim environment for a variety of reasons Signal 10 errors have been found to occur mostly with the V8 2 V8 2_3 and v8 2_5 releases The highest version level of QuickSim with
50. s Getting Started Started with and with AccuSim IT QuickSim II Reference Manual QuickSim II User s Manual Analog Simulators Reference Manual Digital Simulators Reference Manual QuickSim II Training Workbook AccuParts User s Manual System Modeling Blocks User s and Reference Manual Analog Interface Kit Programmer s Guide AccuSim IT Models Reference Manual HDL A Reference Manual Analog Station Training Workbook HDL A Training Workbook SimView Common Simulation User s Manual SimView Common Simulation Reference Manual Charting User s and Reference Manual Design Viewing and Analysis Support Manual Design Viewpoint Editor User s and Reference Manual Digital Modeling Manuals Falcon Framework Manuals Figure 1 Simulation Documentation Roadmap QuickSim II User s Manual V8 5_ 1 XV Related Publications About This Manual Simulation Manuals Design Viewing and Analysis Support Manual contains information about Design Viewing and Analysis Support DVAS DVAS consists of functions and commands that provide selection viewing highlighting reporting grouping syntax checking naming and window manipulating capabilities Design Viewpoint Editor User s and Reference Manual contains information about the Design Viewpoint Editor DVE DVE allows you
51. the Simulator Operating Procedures In both cases the simulator displays a dialog box that queries you about the saving simulation data before you exit The Exit QuickSim dialog box is shown in Figure 3 3 Exit QuickSim After saving Without saving Jm Save Design Viewpoint Design changes are not saved m Save QuickSim setup m Save results Waveform DB OK Reset Cancel Figure 3 3 Exit QuickSim Dialog Box The dialog box only contains categories of simulation data that changed during the simulation session and have not been saved To save simulation data perform the following steps 1 Verify that the After saving button is highlighted 2 Click on each button that corresponds to the categories you want to save 3 Click on the OK button To discard the simulation data click on the Without saving button before executing the dialog box If the simulator is running and you need to stop it you can issue one of the following 2 key entries e CTRL S for HP Apollo platforms 3 14 QuickSim II User s Manual V8 5_1 Operating Procedures Using the Online Helps e CTRL C for UNIX based platforms such as HP PA and Sun Using the Online Helps Online help is available in the following forms Command completion in which you enter a pattern and the simulator responds with a list of the available commands that match For example you can obtain a list of all the available commands that b
52. the capabilities of DVE and how to use it refer to the Design Viewpoint Editor User s and Reference Manual QuickSim II User s Manual V8 5_1 3 5 Invoking QuickSim Il Operating Procedures Invoking QuickSim II You can invoke the simulator for interactive use in the following ways You can invoke the simulator from within the Design Manager e You can issue the quicksim command from an operating system shell Regardless of the method you choose you can set all the simulation conditions that you may require Invoking from the Design Manager The Design Manager provides you a graphical environment that supports Mentor Graphics applications You can use it to copy and move designs access specific design versions and invoke other Mentor Graphics applications The following procedure describes how to invoke QuickSim II from the Design Manager 1 If the Design Manager is not already invoked issue the following shell command SMGC_HOME bin dmgr This command brings up the Design Manager session window which is shown in Figure 3 1 3 6 QuickSim II User s Manual V8 5_1 Operating Procedures Invoking QuickSim Il Design Manager eii MGC Object Edit Setup Windows View Add Report Help PROJECTX _ Navigator TE Ey 2 SETUP SETUP P SESSION MONITOR D mE AD layout library notes are u TRAN SCRIPT MONITOR config sys_1076
53. the occurrence wait until the end of QuickSim II User s Manual V8 5_1 3 75 Using Breakpoints Operating Procedures the timestep on change filter redundant events stop pause the simulator and a list of any actions Deleting Breakpoints To delete breakpoints perform the following steps 1 Choose the following pulldown menu path Menu Bar gt Delete gt Breakpoints The simulator displays the Delete Breakpoints dialog box which is shown in Figure 3 32 Delete Breakpoints AI On Expressions VHDL objects Expression OK Reset Cancel Help Figure 3 32 Delete Breakpoints Dialog Box 2 To delete all breakpoints click on the All button 3 To delete breakpoints that were defined using an expression perform the following steps a Click on the Expressions button b In the Expression name entry box enter the name of an expression you want to delete 3 76 QuickSim II User s Manual V8 5_1 Operating Procedures Back tracing X States To identify the name of an expression create a Breakpoints report window and look in the column labeled Expression 4 To delete breakpoints that were defined using a VHDL object perform the following steps a Click on the Objects button b In the Object name entry box enter the name of a VHDL object you want to delete To identify the name of a VHDL object create a Breakpoints report window and look in the column labeled Object nam
54. this new command to allow direct Design Manager invocation When QuickSim FPGA invokes the application title indicates QuickSim II FPGA During invocation of QuickSim FPGA the kernel checks for an FPGA Station license instead of the QuickSim II kernel license The invocation command alone determines which license is used when QuickSim II invokes The tool will not try to determine from the structure of the design which license to use Likewise QuickSim II User s Manual V8 5_1 B 1 Description of Functionality Invocation of QuickSim Il for FPGAstation QuickSim FPGA invocation will not try to access a regular QuickSim II license when a QuickSim FPGA license is unavailable QuickSim FPGA invocation proceeds similarly to QuickSim II invocation except that models are validated as recognized FPGA design models If the model type is found to be of a recognized type it will be passed to the kernel If the model type is not recognized a NULL model is passed to the kernel and an error message is issued to the transcript and the Simulation Messages window The model recognition process will incur an additional overhead in the invocation process of QuickSim FPGA NOTE For normal QuickSim II invocation the recognition checks are not performed The only affect on QuickSim II is a single check to determine in which mode the kernel is being invoked In addition to FPGA library models two other model types will be analyzed in FPGA desi
55. timing mode uses straight line approximations of the full timing delay values If your design does not include linear technology files and you specify the linear timing mode the simulator uses the full technology files The full timing mode uses full technology files If you wish you can scale the delay values at the same time that you choose either the linear or full timing modes The following describes how to set the timing mode for one or more instances 1 Select the desired instance or instances primitive or nonprimitive Verify that you have only the desired instances selected by looking at the highlighting in the displayed windows You can verify that you have selected only the desired instances by looking at the highlighting in the displayed windows Although instance selection is not required it is generally easier than specifying instance names in the dialog box 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Timing Mode The simulator displays the Change Timing Mode dialog box which is shown in Figure 3 12 3 34 QuickSim II User s Manual V8 5_1 Operating Procedures Setting Timing Modes Change Timing Mode On Selected instances Named instances Timing mode unit Change Delay Scale mo _ Override OK Reset Cancel Help Figure 3 12 Change Timing Mode Dialog Box 3 Make the appropriate choices from the dialog box as follows a Cho
56. to add modify and manage back annotation data as well as define and modify design configuration rules for design viewpoints Fault Analysis User s Manual contains overview information and fault analysis operating procedures relating to the QuickGrade I and QuickFault IT fault analysis applications SimView Common Simulation Reference Manual contains information about the commands functions userware and related reference material for the SimView application This material is also common to all Mentor Graphics digital and analog analysis applications SimView Common Simulation User s Manual describes how to use the SimView application This manual provides background information various simulation procedures and a comprehensive list of related procedures that are common to all Mentor Graphics digital and analog analysis applications Modeling Manuals Behavioral Language Model BLM Development Manual describes how to use the files commands and data structures available with Mentor Graphics software to write BLMs Digital Modeling Guide contains an overview of all digital modeling techniques and their trade offs Getting Started with System 1076 is for digital design engineers who have not previously used System 1076 This training workbook provides basic instructions xvi QuickSim II User s Manual V8 5_1 About This Manual Related Publications for using System 1076 to create and use VHDL models in the Mentor Graphics env
57. trade offs of simulation speed versus simulation accuracy to obtain peak efficiency e The use of all Mentor Graphics simulation modeling methods which allows you to use QuickSim II for simulation during all phases of development e The ability to import Standard Delay File format SDF timing information into a simulation This allows considerable flexibility in timing annotation e The calculation of timing as a function of pin loading and environmental effects such as temperature voltage and process as well as other modeling capabilities With QuickSim II you can apply stimulus to the design run the simulation analyze the results and modify the design based on those results You can then 1 4 QuickSim II User s Manual V8 5_1 Overview of QuickSim Il QuickSim II Overview reset the simulator optionally revise or apply more stimulus to the design the simulator maintains the original set of stimulus and start the cycle over When the design functions correctly you can save the stimulus and simulation results directly with the design to promote consistent and reliable design management How QuickSim II Fits Into the Idea Station Idea Station which operates within the Falcon Framework consists of a set of tools that allow you to capture and analyze your design The Falcon Framework supports capture and analysis work especially through design file management Figure 1 1 illustrates the simulator s role in the Idea S
58. travel log and following hypertext links to view different documents The BOLD Browser provides access to reference help for most Mentor Graphics applications QuickSim II User s Manual V8 5_1 xvii Related Publications About This Manual Common User Interface Manual describes how to use the user interface features that are common to all Mentor Graphics products This manual tells how to manage and use windows the popup command line function keys strokes menus prompt bars and dialog boxes Customizing the Common User Interface describes how to extend the Common User Interface This manual explains how to redefine keys and how to create your own menus windows dialog boxes messages and palettes Design Manager User s Manual provides information about the concepts and use of the Design Manager This manual contains a basic overview of design management and of the Design Manager key concepts to help you use the Design Manager and many design management procedures Getting Started with Falcon Framework is for new users of the Mentor Graphics Falcon Framework This workbook introduces you to the components of the Falcon Framework and provides information about and practice using the Common User Interface Design Manager INFORM Notepad and Decision Support System applications Notepad User s and Reference Manual describes how to edit files and documents in Notepad a text editor This manual provides examples explanations and
59. with X This failure should be pursued in a similar way to the above failure QuickSim II User s Manual V8 5_ 1 A 3 QuickSim Crashes During Invoke with Reference to I s kSim II Troubleshooting QuickSim Crashes During Invoke with Reference to Id so by frequent changes as we continue our work fe This page is under construction Don t be surprised A 4 QuickSim II User s Manual V8 5_1 QuickSim II TroublesfidoK8gn Crashes During Invoke with Reference to __cb_bt QuickSim Crashes During Invoke with Reference to _ cb bt by frequent changes as we continue our work fe This page is under construction Don t be surprised QuickSim II User s Manual V8 5_1 A 5 QuickSim Crashes During Invoke with X QuickSim Il Troubleshooting QuickSim Crashes During Invoke with X _ This page is under construction Don t be surprised by frequent changes as we continue our work A 6 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Quicksim II Hangs During Invocation Quicksim II Hangs During Invocation Problem Scenario A design works correctly in QuickSim until some design changes are made by replacing some hierarchial symbols The design passes Check Sheet and Check Schematic in DA but QuickSim hangs when invoked on the design DVE can open the design viewpoint without difficulty Possible Solutions QuickSim hangs during invocat
60. with the suppress spike model For the suppress spike model the simulator processes spike conditions as follows 1 The simulator removes the scheduled state from the event queue 2 The simulator schedules the new state according to the associated delay The simulation then continues as normal For the X immediate spike model the simulator processes spikes as follows 1 The simulator determines the X immediate state as follows a If the logic value of the current state is not equal to the logic value of the scheduled state and if the logic value of the scheduled state does not equal the logic value of the new state the logic value of the X immediate state is X Otherwise the logic value of the X immediate state is the same as the current state QuickSim II User s Manual V8 5_1 2 25 Spike Models Key Concepts b Ifthe strength of the current state is not equal to the strength of the scheduled state and if the strength of the scheduled state is not equal to the strength of the new state the strength of the X immediate state is I indeterminate Otherwise the strength of the X immediate state is the same as the strength of the current state 2 The simulator removes the scheduled state from the event queue 3 The simulator schedules the X immediate state with no delay and processes it as an event The X immediate state appears on the signal one iteration after the simulator detects the spike and drives the signal for th
61. 1 The simulator processes the force on net A and fans out the result to pin P1 P1 has a 0 delay so an event is scheduled on P1 for the next iteration In the next iteration the simulator processes the event on P1 and fans out the result to instance I1 It then evaluates I1 it changes from 0 to 1 and propagates its state to pin P2 P2 has a 1 nS delay so it schedules an event on P2 in slot 20 TIME 2 The simulator processes the event on P2 and fans out the result to pins P3 and P5 Because P3 has 0 delay it schedules an event on P3 for the next iteration in slot 20 Because P5 has a delay of 2 nS it schedules an event on P5 in slot 40 In the next iteration the simulator processes the event on P3 and fans out the result to I2 It evaluates I2 it changes from 0 to 1 and propagates its state to P4 Because P4 has a 2 nS delay it schedules an event on P4 in slot 40 TIME 4 The simulator processes the event on P5 and fans out the result to I3 It evaluates 3 it changes from 0 to 1 and propagates that state to pin P6 Because P6 has a 0 delay it schedules an event on P6 for the next iteration in slot 40 The simulator processes the event on P4 and fans out the result to net C In the next iteration it processes the event on P6 and fans out the result to net D Figure 2 6 Scheduling Events QuickSim II User s Manual V8 5_ 1 Key Concepts Simulation Timing Modes Simulation Timing Modes The simulator has five timing
62. 38 This waveform database is the default when you invoke the simulator which means the simulator looks in the Results waveform database for data when it displays signal values in the Trace List or Monitor window or when it evaluates an expression or a breakpoint You can save the Results waveform database with the design to establish a performance baseline e Stimulus waveform database This waveform database merges and supplies to the kernel all of the stimulus being applied The kernel deals exclusively with the Stimulus waveform database when it reads stimulus although you can connect to the kernel any number of stimulus providing waveform databases A connected waveform database is one that is linked to the kernel specifically as stimulus The Stimulus waveform database acts like a funnel in that it merges and manages the waveforms from all connected waveform databases and presents a single stream of waveforms to the kernel You can connect any waveform database that is loaded into memory except the Results waveform database The merging capabilities of the Stimulus waveform database allow you to combine portions of separate waveforms You can also use offsets to shift a given waveform either forward or backward in time You cannot save the Stimulus waveform database to disk but you can use it to create logfiles and force files To save connected waveform databases in waveform database format you must separately save
63. ANY INCIDENTAL INDIRECT SPECIAL OR CONSEQUENTIAL DAMAGES WHATSOEVER INCLUDING BUT NOT LIMITED TO LOST PROFITS ARISING OUT OF OR RELATED TO THIS PUBLICATION OR THE INFORMATION CONTAINED IN IT EVEN IF MENTOR GRAPHICS CORPORATION HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES RESTRICTED RIGHTS LEGEND Use duplication or disclosure by the Government is subject to restrictions as set forth in the subdivision c 1 ii of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 A complete list of trademark names appears in a separate Trademark Information document Mentor Graphics Corporation 8005 S W Boeckman Road Wilsonville Oregon 97070 7777 This is an unpublished work of Mentor Graphics Corporation Table of Contents TABLE OF CONTENTS About This Manual xii Related Publications S O XIV Simulation Manuals XVI Modeling Manuals gt xvi Falcon Framework Manuals__ XV Chapter 1 Overview of QuickSim IIL What is Simulation 1 Why Simulate QuickSim IT Overview____ dE How QuickSim II Fits Into the Idea Station 1 QuickSim II Design Flow___ QuickSim II Data Flow SSS Simulator Architecture Input and Output Data SSS 4 Chapter 2 Key Concepts gt 2 1 Electronic Designs___ gt 22 Design Viewpoints and QuickSim H 24 Design Evaluation and Model Selection 2 6 Managing Designs gt _ 2 8
64. Breakpoints QuickSim II User s Manual V8 5_1 Table of Contents TABLE OF CONTENTS continued Back tracing X States___ 8 77 Changing the Design in QuickSim JJ___ S 3 78 Reloading A Model___ P _OO 3 78 Writing Property Changes to a Specific Back Annotation Object________3 80 Swapping A Mode __ _SSSSSSSS 3 81 Changing A Property 38 83 Chapter 4 Operating Procedures Cross Index gt 4l Common Simulation Interface Procedures__t____W _EP 4 1 Design Viewing and Analysis Support DVAS Procedures 4 3 Design Viewpoint Editor Procedures 4 5 Appendix A QuickSim II Troubleshooting CAI Quicksim II Debugging Tips___ SSSA I Quicksim Invocation Fails__ AI QuickSim Fails After Invocation WAI Symptom Invoke Fails__ _ A QuickSim Crash During Invoke SA3 QuickSim Crashes During Invoke with Reference to ld so A 4 QuickSim Crashes During Invoke with Reference to __cb_bt A 5 QuickSim Crashes During Invoke with X A 6 Quicksim II Hangs During Invocation gt gt gt A 7 Problem Scenario A Possible Solutions ___ A EXAMPLE A 7 SOLUTION gt _ A9 QuickSim Crash During Invoke with the Fault Recovery Window_______A 11 Signal 4 Recovery___ A General Instructions for nulling a Model TAN 6229 __ CA 12 Signal 10 Recovery___ A133 The scenarios causing Signa
65. Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Contention Model The simulator displays the Change Contention Model dialog box which is shown in Figure 3 17 QuickSim II User s Manual V8 5_1 3 45 Changing the Contention Model Operating Procedures Change Contention Model On Selected objects Named objects Time 0 Contention can exist this long before a warning is issued Model type A VY Ww None Any Same Different Driven lt Contention pairs See below for examples Note The modeltypes above are ignored if a driven value is given The follwoing are some examples of legal contention pair syntax Pair Definition of when contention exists 1D ania i Sole oh ak Bolo OL Dieiwem boy a Vilet or Vile and 10s driven by any strong and any resistive Driven by any low and 1z OK Reset Cancel Help Figure 3 17 Change Contention Model Dialog Box 3 Make the appropriate choices from the dialog box as follows 3 46 a Choose either the Selected objects button or the Named objects button If you choose the Named objects button you must also complete the Object name entry box To apply the contention model to the entire design you can specify a slash in the Object name entry box b To specify a certain amount of time or grace period that contention must exist before the simulator generates any war
66. Design Properties and Simulation QuickSim II Logic Values and Drive Strengths____ SSSS CSCSCSC S 9 Simulator Accuracy TT Logical Accuracy TT Timing Accuracy How QuickSim II Processes Circuit Activity 2 13 What is Circuit Activity 4 The Timing Whee ___ 14 The Scheduling Algorithm SSS 1 Simulation Timing Modes____ 9 QuickSim II User s Manual V8 5_1 iii Table of Contents TABLE OF CONTENTS continued Delay Scaling 2 Delay Modes__ __ gt _ OO 2 21 Spike Models__ _ 2 A Conditions that Cause a Spike 4 Simulator Spike Models__ _ 2 25 Technology File Configurable Spike Models 2 28 Netdelay Property Spike Model 2 30 Spike Model Simulation 2 30 Spike Message Reporting 2 36 Waveform Databases gt gt 237 QuickSim H Initialization Process____ 2 39 Default Initialization 2 40 Classic Initialization ___SSSSSSSSSSSSSSSS 2 41 Suppressing Warnings During Initialization 2 41 Design Changes in QuickSim HU 2 42 Effects of Design Changes 243 Reloading Models 2 46 Swapping Models gt 47 Changing Properties 47 Back Annotation Objects and QuickSim HU 2 48 EDDM Bundle Functionality__ 249 Hierarchical Pin Keep Functionality 2 49 SDF in QuickSim TL 2 50 The QuickSim Load SDF File Command____
67. Manual V8 5_1 A 17 Cannot Connect to Child QuickSim Il Troubleshooting Cannot Connect to Child _ This page is under construction Don t be surprised by frequent changes as we continue our work A 18 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Too Many Net Recursions Too Many Net Recursions _ This page is under construction Don t be surprised by frequent changes as we continue our work QuickSim II User s Manual V8 5_1 A 19 Parameter Undefined TSUD QuickSim Il Troubleshooting Parameter Undefined TSUD _ This page is under construction Don t be surprised by frequent changes as we continue our work A 20 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting QuickSim Issues Warning Message on Invoke QuickSim Issues Warning Message on Invoke by frequent changes as we continue our work fe This page is under construction Don t be surprised QuickSim II User s Manual V8 5_1 A 21 QuickSim NULLS Model on Invoke QuickSim Il Troubleshooting QuickSim NULLS Model on Invoke _ This page is under construction Don t be surprised by frequent changes as we continue our work A 22 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting QuickSim Loads Wrong Models on Invoke QuickSim Loads Wrong Models on Invoke by frequent changes as we continue our work
68. NETDELAY_DEFAULT name defines a Spike_model statement as the default model for spikes that occur on delayed input paths NETDELAY input pin delay The following example shows how custom spike models are implemented within a Technology File The first model low_pulse uses a triplet of constants to specify the parameters The hi_pulse model illustrates the use of equations The third model is the default model for delayed input paths DECLARE DEFAULT derate_fac 1 define cp pin_n sim_Spin_eval pin_n cap_pin define cn pin_n sim_Snet_eval pin_n cap_net define delay_eqn coef_in coef_out pin_n coef_intcoef_out cn pin_n derate_fac SPIKE MODEL MODEL DEFAULT SUPPRESS PERCENTAGE 40 X_ PERCENTAGE 70 SPIKE _MODEL NETDELAY DEFAULT SUPPRESS_PERCENTAGE 0 netdelay default transporting everything X_PERCENTAGE 0 SPIKE_MODEL low_pulse SUPPRESS_LIMIT 2 4 6 example of triplets X_LIMIT 5 7 9 SPIKE_MODEL hi_pulse SUPPRESS_LIMIT path_del 133 cp i_pin X_LIMIT path_del 276 cp i_pin BEGIN delay statements follow tP 11 13 19 on IN AL to OUT AL SPIKE_MODEL low_pulse tP delay_egqn 853 3 07 out on IN AH to OUT AH SPIKE_MODEL hi_pulse sim_S path_delay in END
69. Not Rising Includes these transitions HX HA HT HU XL AL TL UL FA and the state L General Includes these Technology File transitions XX XA XV XT XU AX AA AV AT AU VX VA VV VT VU TX TA TV TT TU UX UA UV UT UU It includes these states when used in timing checks A V T U e To Hi Z Is defined as XZ AZ VZ TZ and the state Z e From Hi Z Is defined as ZX ZA ZV ZT D 14 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation e Special Cases The transitions ZL ZH HZ LZ UZ ZU and ZZ remain as singular cases Mapping Transition Edges An SDF statement with and input edge specifier will be mapped to all Technology File edges in the timing model with ON pin edges that match the Technology File edge in the Technology File Edge second column of Table 1 below assuming signal names and other conditions match Table D 1 Mapping SDF Edge Specifiers SDF Edge Spec Technology File Edge No edge specified Any posedge Not Falling Rising ZH LZ negedge Not Rising Falling ZL HZ 01 Rising 10 Falling OZ LZ To Hi Z Z1 ZH From Hi Z 1Z HZ To Hi Z ZO ZL From Hi Z A Second Chance If and only if no match is found for an SDF statement it will be retried with the following rules 1 O1 and 10 will be retried as if they were posedge negedge 2 Ifa match for 01 10 posedge or negedge is still not found then Technology File edges
70. P timing model D 2 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il The Annotation Process Support is dependent on model type Built in models AND OR REG LATCH etc and the AMP model types QuickPart Tables QPT QuickPart Schematics QPS and Memory Table Models MTM are fully supported by SDF in A Technology File will not be required if only pin delays PORT and DEVICE statements are being annotated But IOPATHs and TIMINGCHECK statements will be ignored if a Technology File defining them does not exist for the current instance C Behavioral Language Models BLMs that have been written to use Technology Files and RISE FALL delays will also be supported For use in QuickSim II schematic EDDM models may be annotated using distributed delay methods only i e annotate output pins of primitive gates on the schematic sheet since Technology Files and RISE FALL properties are not supported on these hierarchical models Also net delays are annotated onto nets from the schematic model level VHDL models and LMC behavioral models do not support AMP timing models or RISE FALL properties and cannot be annotated using SDF in Property annotation is bypassed Since annotations to pin and net delays are being done directly to the timing cache the database properties such as RISE and FALL associated with these delays will NOT be changed or added to reflect their annotated values This is even if the property is visi
71. Procedures that are found in the Design Viewpoint Editor User s and Reference Manual Opening a Back Annotation Object Connecting a Back Annotation Object Back Annotating a Design Disconnecting a Back Annotation Object cont Prioritizing Multiple Back Annotation Objects Sharing PCB and Simulation Back Annotations Importing an ASCII Back Annotation File Exporting a Back Annotation Object Viewing and Analyzing the Viewing Schematic Sheets and VHDL Design Text Additional Operating Procedures Changing Model Representations 4 6 QuickSim II User s Manual V8 5_1 Appendix A QuickSim Il Troubleshooting GNapnice Quicksim II Debugging Tips Welcome to the world of QuickSim II Debugging Quicksim Invocation Fails e Symptom Invoke Fails This section describes a group of failures that appear when QuickSim is invoked In this case the tool will exit before it completes loading QuickSim Fails After Invocation Symptom QuickSim Fails After Invocation This section describes a group of failures that occur after QuickSim has invoked In this case QuickSim reaches a point where the user can issue commands in the application _ This page is under construction Don t be surprised by frequent changes as we continue our work QuickSim II User s Manual V8 5_1 A 1 Symptom Invoke Fails QuickSim Il Troubleshooting Symptom Invoke Fails QuickSim Crash
72. QuickSim II User s Manual Software Version 8 5 1 Copyright 1991 1995 Mentor Graphics Corporation All rights reserved Confidential May be photocopied by licensed customers of Mentor Graphics for internal business purposes only The software programs described in this document are confidential and proprietary products of Mentor Graphics Corporation Mentor Graphics or its licensors No part of this document may be photocopied reproduced or translated or transferred disclosed or otherwise provided to third parties without the prior written consent of Mentor Graphics The document is for informational and instructional purposes Mentor Graphics reserves the right to make changes in specifications and other information contained in this publication without prior notice and the reader should in all cases consult Mentor Graphics to determine whether any changes have been made The terms and conditions governing the sale and licensing of Mentor Graphics products are set forth in the written contracts between Mentor Graphics and its customers No representation or other affirmation of fact contained in this publication shall be deemed to be a warranty or give rise to any liability of Mentor Graphics whatsoever MENTOR GRAPHICS MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MATERIAL INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OR MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE MENTOR GRAPHICS SHALL NOT BE LIABLE FOR
73. QuickSim to see if the error messages are cleared Otherwise you should begin by checking the design references and then run a simulation design check in DVE QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Signal 13 Error Message Signal 13 Error Message Through V8 2_5 QuickSim version 8 2_10 1 there have been 3 conditions known to generate the signal 13 error message and crash The first condition is related to the use of control c to stop an ample script In the cases where QuickSim crashed with a signal 13 message the crash was often proceeded by the use of the control c to stop the ample script or simulation The use of control s to interrupt an ample script is a better choice than control c There have been a number of problems in the use of control c that are corrected in the A 1 F V8 4 release The second condition is caused by a floating license failure This situation was resolved by using a nodelock license The third condition is caused by the unix XSET containing no MGC font pathnames This could also happen if the pathnames are defined but are wrong For more information about problems in the use of control c and control s see Tans 6366 QuickSim II User s Manual V8 5_1 A 15 Symptom Memory Fault QuickSim Il Troubleshooting Symptom Memory Fault Memory Fault problems are generally indicative of problems in loading data into memory
74. QuickSimII m ee For ots ba we fe T I results sample_ba sample_co NAVIGATE TOOLS fe ee dypt design_arch DVE Editor ape gs ie ERE TRAN T ARCHY SCRIPT 5l a fal a ample_dvpt sheet 1 symbol Ni a aD l e CONFIG TRASH SimVieyQuickGradell ka 4 fi ill h FO F1 F2 F3 F4 Il e a Fe I F F8 ulldown Men Open Object Unselect All Goto Director Popup Menu Move Object Search how Referen Open Monito pen Navigato Select Objec xplore Paren S Copy Object Search Agail jange Refere rowse Objec Report Info Select All vigator Direct c ge Object Na Reck neferen a ind Referenc See eee Figure 3 1 Design Manager Session Window The Tools window which is in the left side of Figure 3 1 contains icons that represent applications The navigator window which is titled PROJECTX contains icons that represent data objects 2 To invoke the simulator from the Design Manager s navigator window perform the following steps a Click on a component or design viewpoint icon to select it As shown in Figure 3 1 the component icon is labeled sample_comp and the design viewpoint icon is labeled sample_dvpt The Design Manager highlights the icon to indicate that
75. S 01 10 0Z Z1 1Z ZO OX X1 1X XZ ZX UT X X UU X X UV X UX X UZ X VA VH VL VT VU VV VX VZ XA XH XL XT XU XV XX XZ X X X ZA ZH ZL ZT ZU ZV ZX ZZ X X X X IPS PS Ts gt gt lt J lt gt lt P lt SI P lt P P P P lt lt SI PI PS OPS IPS a lt gt lt gt lt JSI P lt lt lt JI PI lt gt lt JI P lt lt KI PI lt D 20 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation Special Case Subordinate Technology File Edges The SDF IOPATH delay IOPATH posedge clk q 12 11 10 9 8 7 6 5 4 3 2 1 maps to all three Technology File edges below tP 13 ON clk LH TO q LH tP 17 ON clk LH TO q AH tP 19 ON clk LH TO q AA According to the table all three Technology File edges choose a delay of 12 since all look in the first table column for data While this appears correct at first it is not a best fit with the intention of the Technology File When more that one edge to an output is active Technology Files resolve ambiguity by choosing the first statement based on order of appearance So in QuickSim II transitions on Q from 0 to 1 will always use the first Technology File statement LH even though all three statement are active Transitions on Q
76. SSSSSSCB I Appendix C QuickSim II Environment Variables__ CC Introduction S C Table of Environment Variables gt gt gt gt C l QuickSim II User s Manual V8 5_1 vii Table of Contents TABLE OF CONTENTS continued Appendix D SDF in QuickSim TTS IT Overview DT OVI SDF Versions Supported D I The Annotation Proces gt gt D2 Setting the Time Scale gt D2 Defining Timing Models D 2 The Role of the Timing Cache D 3 Making SDF Annotations Persistent D4 Conflicts between SDF and other Database Changes D 5 Annotating Specific Timing Modes D 6 SDF Technology File Correlation Correlating Instance Paths___ SSD 7 The AMP Timing Model D 8 SDF CELL Templates gt D8 Correlating an SDF Statement with a Technology File Statement D 8 Index viii QuickSim II User s Manual V8 5_1 Table of Contents LIST OF FIGURES Figure 1 Simulation Documentation Roadmap Figure 1 1 Figure 1 2 Figure 1 3 Figure 1 4 Figure 1 5 Figure 1 6 Figure 2 1 Figure 2 2 Figure 2 3 Figure 2 4 Figure 2 5 Figure 2 6 Figure 2 7 Figure 2 8 Figure 2 9 Figure 2 10 Figure 2 11 Figure 2 12 Figure 2 13 Figure 2 14 Figure 2 15 Figure 2 16 Figure 2 17 Figure 2 18 Figure 3 1 Figure 3 2 Figure 3 3 Figure 3 4 Fig
77. SSSSSSSSSSSSSSSSSSSSSSFSFSCSCSC lt 5 Importing an SDF file Using TimeBase____ _ gt P 5 Chapter 3 Operating Procedures gt gt Processing a Design For Simulation 33 Invoking QuickSim I ___ 3 6 Invoking from the Design Manager 3 6 Invoking from A Shel _____SSSSSSSSSSSSSSSSSSSSSSSSSSSS 3 10 Running a Batch Simulation TT Using Redirected Input__ 8 Using Here Documents gt 3 12 iv QuickSim II User s Manual V8 5_1 Table of Contents TABLE OF CONTENTS continued Exiting and Suspending the Simulator Using the Online Helps Command Completion Quick Help Reference Help Setting Up QuickSim II Setting Up the Kernel Setting Up Instance By Instance Initializing the Design Suppressing Initialization Warnings Saving Setup Conditions Restoring Setup Conditions Setting Timing Modes Loading an SDF File Checking for Design Constraints Changing the Spike Model Checking for Spike Conditions Changing the Contention Model Checking for Contention Checking for Hazard Conditions Displaying Model Messages Reporting Model Statistics Gathering Toggle Statistics Reporting Toggle Statistics Checking Device Stability Keeping Circuit Activity Applying Stimulus to a Simulation Using the Palettes Running the Simulator Resetting the Simulator Saving and Restoring Simulation States Using Breakpoints Adding Breakpoints Reporting Breakpoints Deleting
78. Some user interface operating procedures are documented in the SimView Common Simulation User s Manual Processing a Design For Simulation In general after you create your component you can immediately invoke the simulator on it When the simulator invokes on a design without a viewpoint for the first time it creates a design viewpoint with a default configuration This in memory design configuration provides the information that the simulator needs by default such as which models are primitives and which properties are visible to the DFI design file interface Although a default configuration is sufficient for some designs many situations require you to create a design viewpoint with a custom configuration For example if your design uses parameters you must create a custom configuration to define their values To create a custom configuration you must use the Design Viewpoint Editor DVE DVE allows you to define parameters and specify which models are primitives The following specific conditions require you to use DVE e If you change the configuration of the design by either setting the level of primitiveness setting initial values for property variables substituting property values or defining which properties are visible to DFI e If you connect disconnect or change the connecting priorities of back annotation objects e If you browse the back annotations that have been applied to your design o If you browse the speci
79. T restore WDBs Restore All Saved Setup Groups This option hides the group choice area default By disabling this button as shown in Figure 3 11 you can choose the groups to be restored A description of the contents of each setup group is described in Table 3 2 on page 3 29 2 Fill in the dialog box accordingly 3 Click on the OK button The simulator then restores the setup conditions Setting Timing Modes You can enable timing modes to choose the timing values that your design uses during the next simulation run The timing modes consist of the following Unit delay e Linear timing using either minimum typical or maximum delay values Full timing using either minimum typical or maximum delay values You can set the timing mode at the root level of the design either when you invoke the simulator or during the simulation session You can also set the timing mode for specific instances QuickSim II User s Manual V8 5_ 1 3 33 Setting Timing Modes Operating Procedures All settings affect the design hierarchically That is if the specified or selected portion of the design contains one or more hierarchical levels is not primitive all lower levels inherit the setting unless it is overridden by a similar setting at a lower level The unit delay timing mode causes the simulator to ignore technology files and Rise and Fall properties and to instead use a delay of one timestep for all affected instances The linear
80. This section contains brief descriptions of design database objects An electronic design sometimes simply called a design is a software representation of an electronic device which can be as simple as a logic gate or as complex as an entire system You create a design with Electronic Design Automation EDA applications Figure 2 1 represents an electronic design Back Annotation Electronic Components Design tb z 4 Design Viewpoint ne A QuickSim Il Symbols 4 Timing Functionality Connectivity Figure 2 1 An Electronic Design As Figure 2 1 shows a design must include both a component and a design viewpoint A component is an object that contains a set of associated models Each model describes an aspect of the design functional which can include connectivity graphical timing or technology A design viewpoint is a data object that contains a set of configuration rules Configuration rules define the kinds of design information that an application must have to perform its job In the case of QuickSim II this information includes how the design elements are connected the functionality of the modeled devices and the signal relationships and timing A design can have multiple design 2 2 QuickSim II User s Manual V8 5_1 Key Concepts Electronic Designs viewpoints but the digital analysis applications typically use the same one Also a design viewpoint can r
81. _1 1 17 QuickSim II Overview Overview of QuickSim Il e Window Plots Contain window data printed by the specified printer For example you can plot Trace windows Back Annotation Objects Contain changes to the design that were made in tools other than the Design Architect For example when you change a property within QuickSim II the change is added to the back annotation object For more information about back annotation objects refer to Back Annotation Objects and QuickSim IT on page 2 48 The next chapter describes the key concepts that pertain to QuickSim II and to digital logic simulation 1 18 QuickSim II User s Manual V8 5_1 Chapter 2 Key Concepts This chapter contains the following sections Electronic Designs __ 2 D Design Viewpoints and QuickSim H ____SSSSSSSSSSSSSSSSSSSS 2 4 Design Evaluation and Model Selection 2 6 Managing Designs __ _ 28 Design Properties and Simulation DD QuickSim II Logic Values and Drive Strengths 29 Simulator Accuracy TT How QuickSim II Processes Circuit Activity 2 13 Simulation Timing Modes S 2 19 Delay Scaling 2 2 Delay Modes ___ 2 2 Spike Models 24 Waveform Databases _ 2 37 QuickSim II Initialization Process 2 39 Design Changes in QuickSim IJ 242 SDF in QuickSim TJ 2 50 QuickSim II User s Manual V8 5_1 2 1 Electronic Designs Key Concepts Electronic Designs
82. _des PINS Compiled User Id Pin Name Pin Name Properties 1 gb gb pintype out pin qb 2 q q pintype out pin q 3 CLE clr pintype in pin clr 4 k k pintype in pin k 5 clk clk pintype in pin clk 6 j j pintype in pin j T pre pre pintype in pin pre BODY PROPERTIES There are no Body Pr NTERFACE MODEL ENTRIES Model Entry Type Model Info 0 mgc_schematic Path STIMP schematic Labels schematic Sschematic default Status Valid for interface Valid for property 1 mgc_symbol Path test_des Labels default_sym Status Valid for interface Valid for property SOLUTION If you suspect that your design contains a circular reference you should first check with all individuals who would have had an opportunity to alter the design since your last successful invocation of QuickSim Another approach is to try and break the design into smaller blocks and check each block to see if DVE can perform a Design Check Once you find a block that hangs during a Design Check note which block it is in the design You will have to kill the DVE session to exit Continue this process for all blocks at this level of the design hierarchy QuickSim II User s Manual V8 5_1 A 9 Quicksim II Hangs During Invocation QuickSim Il Troubleshooting Once you have located a block that you believe to be the problem you can verify it by attempting to OPEN DOWN on the block from DVE If the block is t
83. able Table C 1 Description AMPLE_PATH Specifies unique application userware area LANG Specifies unique application userware area LM_LICENSE_FILE Location of license file data MGC_HOME QuickSim II User s Manual V8 5_ 1 Locates the Mentor Graphics software tree Table of Environment Variables QuickSim II Environment Variables Table C 1 Variable Description MGC_LOCATION_MAP Provides a map between soft and hard pathnames to component libraries MGC_QSIM_GLOBAL_ On invocation the EDDM determines the NET_SHORT design wide global net names This give correct global name in reports Because invocation performance is reduced 5 7 use variable only if necessary MGC_SDF_ Provides more detail on the correlation of TEMPLATES the SDF file s CELL templates to the Technology File Templates are dumped in ASCII form Variable value not checked MGC_SHOW_INT_TMG If TRUE statements automatically generated for internal signal be included in Report Timing window If FALSE or missing internal statements are hidden MGC_ lt library_name gt Path to MGC components library MGC_WD Sets context for filename paths and navigation windows MGLS_LICENSE_FILE Location of license file data C 2 QuickSim II User s Manual V8 5_1 Appendix D SDF in QuickSim Il Overview QuickSim IT now allows you to import Standard Delay File SDF formatted information to be im
84. ame entry box b Click the appropriate Spike warnings to display button to enable spike checking spike checking as follows o Suppress This enables reporting of spikes that cause the previously scheduled event to be suppressed o Transport This button enables reporting of spikes that are transported o X This button enables reporting of spikes that generate an X either immediately or delayed QuickSim II User s Manual V8 5_ 1 3 43 Changing the Contention Model Operating Procedures o Display All Warnings This will enable all three Suppress Transport and X warning types c To override the spike checking set at levels below the selected or specified instances click on the Override button Note that this button will not override lower level spike warning settings that were also set with the Override button 4 Activate your choices by clicking the OK button at the bottom of the dialog box Changing the Contention Model You can direct the simulator to check for contention conditions which happens when more than one pin is driving a given net You check for contention by first setting the contention model on targeted nets and then enabling contention checking If the simulator finds that a contention condition exists it generates an error message citing the pins that are responsible and the net where it occurred To more fully understand the descriptions of how contention works you should know the following
85. an alphabetical listing of AMPLE functions that are available for customizing Notepad xviii QuickSim II User s Manual V8 5_1 Chapter 1 Overview of QuickSim II This chapter provides important background information about QuickSim II This background information can help you to use QuickSim II effectively This chapter contains the following sections What is Simulation dd Why Simulate dB QuickSim II Overview SSS B How QuickSim II Fits Into the Idea Station 1 5 QuickSim H Design Flow S 16 QuickSim H Data Flow gt 10 Simulator Architecture dd Input and Output Data___ i d What is Simulation Simulation is the modeling exercising and behavior analysis of an electronic design without the ownership costs of the physical hardware QuickSim II calculates the behavior of a design and provides useful displays that you can use for analyzing the behavior It provides a reality check that gives you confidence in your design work To analyze an electronic design you must either have the design physically available or a representative model whose behavior can be simulated If you use a representative model it must have all the attributes of the physical design and the test bench environment Because QuickSim II allows different types of models you can use it all the way through your design process During functional simulation which happens early QuickSim II User s Manual V8 5_1 1
86. ance Unit delay is the default timing mode Use this mode to debug fundamental design functionality In this mode all output and IO pins use a rise and fall delay of 1 timestep default is 0 1 nanosecond and input pins use a rise and fall delay of 0 The simulator ignores technology files When you finish debugging your design in unit delay you can proceed to the linear if the design includes linear technology files or to full timing mode Linear timing Provides straight line approximations of the full timing that is defined by the associated technology files You can use this mode to debug the effects of timing on your design s functionality but it is available only if your design uses library components that provide linear technology files When you use linear timing a typical design s timing is computed approximately 10 times faster than when you use full technology files Linear timing with constraint checking Provides straight line timing approximations with full constraint checking You can use this mode to produce timing violation messages as you begin debugging your design s timing As with the linear timing mode you can use this timing mode only if your design uses library components that provide linear technology files When you are satisfied with your design s performance in this mode the next step is to use full timing with constraint checking Full timing Provides full timing accuracy Use this timing mode to debug the effe
87. and starts the process over Again null simulation models behave the same as an open circuit Managing Designs The Design Manager is an icon based application that helps you manage your designs Within the Design Manager you can directly invoke other Mentor Graphics applications as well as perform data management tasks such as copying moving archiving and releasing your design data It also supplies a design data navigator and a full set of self explanatory icons for data representation For more 2 8 QuickSim II User s Manual V8 5_1 Key Concepts Design Properties and Simulation information about the Design Manager refer to the Design Manager User s Manual Design Properties and Simulation A design property consists of a name and a value and it helps describe model and design characteristics for Mentor Graphics applications Properties help describe three schematic items symbols pins and nets A symbol is a graphical representation of a component a pin is the point that connects the net to the circuitry represented by the symbol and a net is a signal path that connects two or more pins Examples of design characteristics that properties define are pin rise and fall times the initialization state of a pin or net and the logic function associated with a symbol body Simulation design properties are discussed in the Simulation Design Properties chapter of the Digital Simulators Reference Manual and all properties
88. any event must be due to a logic level change For devices which consider strength values the X pulse state is determined by the same algorithm used for the X immediate spike model that is changes in level and changes in strength are considered independently Note that a state in QuickSim II consists of a level 0 1 X and a strength S R Z I The X pulse state level will be X if there are two changes in level in the transitions state to statel and statel to state2 Similarly if the device passes strength values such as with the QuickSim II delay gate primitive the X pulse strength value will be I if there are two changes in level For example given a delay gate the transitions Os to 1s to Os would result in an X pulse state of Xs The transitions of Os to Ir to 1s would yield an X pulse state of 1I The transitions Os to Ir to Os would yield an X pulse state of Xi X Pulse Behavior The behavior in this region differs depending on whether X IMMEDIATE is declared in the SPIKE_MODEL The following sections illustrate this behavior X immediate not specified This is the default case The state scheduled for event is changed from state1 to the X pulse state as described above The output changes from state0 to the X 2 32 QuickSim II User s Manual V8 5_1 Key Concepts Spike Models pulse state at time tl d1 and to state2 when event2 matures at time t2 d2 This is shown in Figure 2 14 suppress limit 4 lt gt
89. are described in the Properties Reference Manual QuickSim Il Logic Values and Drive Strengths QuickSim II uses 12 signal states to simulate a logic circuit A signal state represents the electrical state of a signal Each signal state is a combination of a logic value and a drive strength These signal states provide a comprehensive and accurate approach to the simulation of logic designs The simulator uses three logic values 0 1 and X The X value represents a logic value that could be either 0 or 1 but cannot be reliably determined During simulation X logic values can occur at design initialization as the simulator tries to determine design power up conditions An X logic value can also be the result of signal contention which happens when two or more logic values are driven simultaneously onto the same net Signal drive strengths allow the simulator to accurately resolve signal contention and to simulate subtle effects of different design technologies The simulator uses QuickSim II User s Manual V8 5_ 1 2 9 QuickSim Il Logic Values and Drive Strengths Key Concepts four signal drive strengths strong S resistive R high impedance Z and indeterminate I The I value represents a signal strength that could be either S R or Z The simulator combines the signal drive strengths with the three logic values to create the 12 signal states required for comprehensive and accurate simulation of the different design te
90. at best suits your needs Each Timing mode button corresponds to a set of setup conditions and are described as follows The Current button maintains the design s current timing mode e The Unit button establishes unit delay and disables all forms of simulation checking 3 20 QuickSim II User s Manual V8 5_1 Operating Procedures Setting Up QuickSim Il e The Delay button establishes full timing using the typical Rise and Fall property values and the typical pin to pin delays from technology files The Delay button does not enable any constraint or simulation checking capabilities e The Constraint button establishes full timing using all typical values and enables constraint violation messages and all simulation checking capabilities Each Timing mode button establishes default setup conditions that you can set explicitly as described in the next step To override design setup conditions for a specific instance refer to Setting Up Instance By Instance on page 3 23 3 To see a detailed account of the setup conditions that a particular Timing mode button establishes click on the Visible button The Visible button expands the dialog box so you can view and choose setup conditions that are more specific than those provided by the Timing mode buttons The expanded Setup Analysis dialog box that corresponds to the Delay button is shown in Figure 3 5 NOTE The buttons in Figure 3 5 contain hyperlinks Each hyperlink
91. atabase Provides stimulus directly to the design The simulator automatically converts Force commands individually or grouped in a force file MISL files and logfiles into a binary format called a waveform database You can then save the waveform database and use it for future simulations which is faster than using the original forces MISL files or logfiles Design Viewpoint Provides the design configuration rules that the simulator uses when reading the design The design viewpoint also serves as an area for storing other data objects that are related to the application such as save state data objects setup data objects the timing cache and waveform databases Modelfiles Specify the programming of memory devices in the design Modelfiles are ASCII files that are associated with RAMs ROMs PLAs and PLDs through the Modelfile property e Picture Objects Provide the graphical information to display the schematic of a circuit in the schematic view window QuickSim II User s Manual V8 5_1 1 15 QuickSim II Overview Overview of QuickSim Il Back Annotation Objects Contain design property changes that were made in tools other than the Design Architect Back annotation objects are attached to the design viewpoint e Setup Objects Contain information about the simulator s initial setup conditions You can restore a setup to establish the same conditions that you established in a previous simulation session e Save S
92. ble on a sheet view SDF in users in QuickSim II should use the Report Timing command to see the timing data being used by an instance The Role of the Timing Cache While SDF eliminates the need for complex timing equations TimeBase is still needed to create a timing cache for the design using the design s Technology Files and an EDDM design viewpoint As always this may be done by invoking TimeBase as a stand alone tool or by invoking QuickSim II in MIN TYP or MAX timing mode Once created the timing cache can be annotated with SDF data The timing cache can be saved between QuickSim II sessions for a faster second invocation time QuickSim II User s Manual V8 5_1 D 3 The Annotation Process SDF in QuickSim Il For the purpose of data management the user should consider the SDF source to be the persistent timing data as the timing cache is volatile The timing cache can become invalid when a design changes between sessions If the timing cache becomes invalid you must reissue the Load SDF File command again to reannotate the timing cache AMP Library SDF File Technology Files QuickSimll SDF in TimeBase ha ce ae Step 1 RER Create a Timing Timing Cache Cache with tenes Model Info Ley Step 2 Data Annotate Timing Data with SDF in Figure D 1 SDF Annotation Process Making SDF Annotations Persistent Once a Load SDF File command has been execute
93. ce from in1 to int_st to out 99 tP eq1 eq2 ON int_st TO out In this example SDF in may annotate either or both of the two statements that appear in the Technology File in which case the data for the generated arc is adjusted accordingly Example IOPATH inl out 1 2 3 this is legal But the third arc can not be annotated directly from SDF in IOPATH int_st out 1 2 3 this is NOT legal Also SDF may not annotate internal states using the pin delay PORT or DEVICE statements Correlating Statement Type DELAY statements are e IOPATH maps to Technology File DELAY tP statements e PORT maps to input pin RISE FALL properties e INTERCONNECT maps to Technology File NetDelays or NetDelay pin properties The SDF NETDELAY statement is not supported in this release e DEVICE maps to output pin Rise Fall properties A few additional notes D 10 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation If only PORT and DEVICE statements appear in the SDF file then Technology Files are not needed to annotate delays to primitive AMP instances since they can support pin delays without them Specified edge transitions are manifested in the syntax of these SDF statements and will be mapped to the proper Technology File statements A COND precursor will act as a WITH condition for IOPATHs tPs Some of the operators used in SDF have no comp
94. chnologies TTL designs typically require only five of these logic value signal strength combinations 0 and 1 for driving devices X for either 0 or 1 but you don t know which 1R for pull up resistors and XZ for any high impedance signal level By substituting a OR in place of the 1R you can accurately model ECL and its pull down resistors The need to accurately model MOS designs at the transistor level led to the indeterminate signal strength enlarging the state strength table to 12 combinations Table 2 2 shows the resulting combination map that QuickSim II uses Table 2 2 Simulation State Values Signal Level Drive Strength Low 0 High 1 Unknown X Strong S OS 1S XS Resistive R High Impedance Z Indeterminate 1 Most logic simulators currently operate with these or similar states and strengths QuickSim II however uses an additional drive strength that cannot be overridden by contending signals which allows you to simulate a driving positive voltage level VCC or ground level GND This overriding drive condition is a fixed drive which is different from the simple strong S drive For example when the 1S and OS signal states are combined the result is XS However a fixed signal state of 1S which you would use to model a VCC connection always overrides any other contending signal state during a simulation stays fixed at 1S in this example You can also create stimulus tha
95. cified The following actions will be disabled until the above time 1 Constraint Contention Spike Hazard and model warning messages 2 MTM memory invalidations OK Reset Cancel Help Figure 3 8 Change Warning Start Dialog Box 2 Enter the grace period time in the first entry box This is the time prior to which warnings and violation actions will be suppressed 3 Click on All default to suppress all types of warnings and violation actions User Specified to reveal the types of warnings included Figure 3 9 shows the choices that are allowed if User Specified is chosen All User Specified __ Constraint messages __ Hazard messages _ Contention messages __ Model messages _ Spike messages __ MTM invalidations Figure 3 9 Change Warning Start User Specifications 4 Click on the specific User Specified warnings and violations to suppress 5 Click on the OK button 3 26 QuickSim II User s Manual V8 5_1 Operating Procedures Saving Setup Conditions The simulator saves the Warning Start information in the setup conditions which can be restored upon invocation These conditions are valid after a Reset State operation Multiple Warning Start specifications can be made for different times For examples refer to the Change Warning Start command in the Digital Simulators Reference Manual Saving Setup Conditions You can save your setup conditions in a design
96. cify that only the minimum or only the maximum timing values be scaled Delay Modes The simulation delay mode determines how the simulator propagates and schedules signal transitions that involve delays The simulator uses either inertial or transport delay mode The delay mode always affects the entire design The simulator ignores the delay mode for instances using the unit delay timing mode The inertial delay mode which is the default delay mode when you invoke the simulator of the following behaviors e Enables the simulator to recognize and process spike conditions for information about spike conditions refer to page 2 24 Applies to all delay types pin Rise and Fall properties Netdelay properties and pin to pin delays from technology files The transport delay mode which you can request when you invoke the simulator consists of the following behaviors e Disables spike recognition and processing for all pin to pin delays Propagates all events through a device according to the pin to pin delay specified regardless of the frequency of the events QuickSim II User s Manual V8 5_1 2 21 Delay Modes Key Concepts e Applies to only pin to pin delays all other delays always use the inertial mode ma Logic Models that are created with the LM Family of hardware i modelers always use the transport delay for all pin to pin delays Note To help illustrate the differences between the inertial and transport delay mod
97. ck the On change button QuickSim II User s Manual V8 5_ 1 Operating Procedures Using Breakpoints e To specify how many times the breakpoint conditions must occur before the simulation is interrupted use the On occurrence entry box f To interrupt evaluate the simulation after the completion of the timestep in which the breakpoint occurs click on the End of timestep button If the End of timestep button is unhighlighted the simulation is interrupted evaluated after the iteration in which the breakpoint occurs which is generally desirable when setting breakpoints on VHDL objects g To issue one or more functions when the breakpoint occurs enter the functions in the Action list entry box The function must conform to all AMPLE syntax requirements 4 Click on the OK button Reporting Breakpoints To report all of the defined breakpoints elect the following pulldown menu path Menu Bar gt Report gt Setup gt Breakpoints The simulator display a Breakpoints report window which is shown in Figure 3 31 lt unset gt clk 1 1 T T T T T o lt unset gt sel_out 3 T T T F F lt e Object name Expression On occurrence End Change Filter Stop Delay Act 38 lt empty gt 1 F F F F F lt e l PN amp Figure 3 31 Breakpoints Report Window A breakpoints report window provides information about each breakpoint including the object name any expressions
98. click on the Override button Note that this button will not override lower level contention checking that was set with the Override button 4 Click the OK button to activate your choices Checking for Hazard Conditions A hazard condition exists when an output or IO pin changes to two or more different states during successive iterations of the same timestep The simulator QuickSim II User s Manual V8 5_ 1 3 49 Checking for Hazard Conditions Operating Procedures uses and propagates the last event that occurs which is determined by circuit connectivity and activity You can set hazard checking on nets buses and hierarchical non primitive instances The following procedure describes how to control hazard checking 1 Select the desired nets buses or nonprimitive instances You can verify that you have selected only the desired objects by looking at the highlighting in the displayed windows Although object selection is not required it is generally easier than specifying names of objects in the dialog box created in the next step 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Hazard Check The simulator displays the Change Hazard Check dialog box which is shown in Figure 3 19 Change Hazard Check On Selected objects Named objects Hazard check A Off _ Override X2 on Figure 3 19 Change Hazard Check Dialog Box 3 Make the appropriate choic
99. cts of timing on your design s functionality This mode uses all technology file equations any rise or fall pin delays and BLM and VHDL delay instructions When you are satisfied with your design s performance in this mode the next step is to use full timing with constraint checking Full timing with constraint checking Provides complete timing accuracy with full constraint checking You can use this mode to produce timing violation messages during full circuit debugging operations This mode uses all technology file specified timing equations any rise and fall pin delays and BLM and VHDL delay instructions This mode also checks for timing constraints and spike contention and hazard violations Note that you can disable each of the constraint checks independently with separate QuickSim II User s Manual V8 5_ 1 Key Concepts Delay Scaling commands This mode gives you the greatest number of timing and debugging capabilities but at the greatest cost to simulator performance Delay Scaling When you use any mode except unit delay you can specify a delay scaling factor The simulator multiplies the delay values pin and path delays of the affected instances by this scaling factor You can scale delay values on a design wide or instance by instance basis Design wide scaling gives you a fast and convenient estimate of how derating might affect the simulation Although the default is to scale typical timing values you can also spe
100. d QuickSim II Userware 4 SimView UI DVAS R Mouse Common Sim ser Interface DSC a QuickSim Il Kernel lt 4 gt J Electronic Design Database la n Waveform Databases Figure 1 4 Architecture of QuickSim Il The following list defines the major elements of the simulator architecture e Front End Communicates with the user through the session windows keys and mouse the design data and the QuickSim II kernel 1 12 QuickSim II User s Manual V8 5_1 Overview of QuickSim Il QuickSim Il Overview QuickSim II Userware Consists of menus key definitions applications windows commands and so on that enhance the usability of the simulator Common Simulation User Interface Consists of a set of commands common to all Mentor Graphics simulators that let you interact with the simulation and display the simulation results for analysis e DVAS Design Viewing and Analysis Support Lets you select view group and report on design items DVE Design Viewpoint Editor Lets you perform incremental design changes during the simulation e SC Simulation Checker Lets you check simulation properties during the simulation session The SC is useful after making incremental design changes Electronic Design Database Contains t
101. d in QuickSim II the in memory copy of the timing cache has been loaded with new data The annotated timing cache will not become persistent unless it is explicitly saved to disk with a Save Design Viewpoint or Save State command Saving the timing cache is recommended to avoid unnecessarily running TimeBase during the next invocation of QuickSim II There is no direct way to disconnect the SDF annotations But quitting the QuickSim IT session without make the timing cache persistent will have the effect of restoring the timing data to its pre SDF state D 4 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il The Annotation Process Conflicts between SDF and other Database Changes Changes During a QuickSim Il Session Design changes that occur in QuickSim II incremental changes may cause timing cache invalidation that may obscure SDF annotated data Methods and rules to manage this problem are defined to limit problems Locking the Timing Cache in QuickSim Il Once a Load SDF File command has been executed in QuickSim II or if SDF is imported in TimeBase the timing cache is locked This means Connectivity changes such as reload model or changing the MODEL property are rejected by QuickSim II and an explanatory warning is issued This is true even if the change is in an area that has not been annotated with SDF This avoids unexpected side effects caused by net reconstruction that may connect any two parts of the design e
102. d model registration refer to the DA Model Registration in the Design Architect User s Manual Configuration rules in the design viewpoint The configuration rules identify how far the simulator traverses the design hierarchy as it looks for primitive instances These rules can differ between a default configuration which the simulator creates and a custom configuration which you create in the Design Viewpoint Editor 2 6 QuickSim II User s Manual V8 5_1 Key Concepts Design Evaluation and Model Selection Before the simulator begins evaluating the design it reads the configuration rules in the design viewpoint Figure 2 2 shows the simulator s design evaluation and model selection process Begin Design Evaluation m Get next instance Get instance s Model property Match Model property to labels lt Is model lt valid for simulation N o lt Successful YES match Descend to VHDL or schematic Insert a NULL simulation model Build representation Figure 2 2 Model Selection Flow Chart Beginning with the root instance of the design the simulator performs the following steps to evaluate the design and select the simulation models 1 Beginning with the root instance the simulator determines if the current instance is a primitive according to the configuration rules in the design viewpoint In the resulting design repres
103. data object if you establish a setup environment that you want to reuse To save a set of setup conditions perform the following steps 1 Choose the following pulldown menu path Menu Bar gt File gt Save gt Setup The simulator then displays the Save Setup dialog box which is shown in Figure 3 10 QuickSim II User s Manual V8 5_1 3 27 Saving Setup Conditions Operating Procedures 3 28 Save Setup __ Viewpoint Pathname quicksim_setup Navigator _ Replace jm Query when Waveform DBs have edits pending a Save All System Setup Groups Specify the System and or System Setup groupe User defined setup groups to save actionpoints assertions User defined setup groups breakpoints buses chart_windows context cycles expressions OK Reset Cancel Help Figure 3 10 Save Setup Dialog Box The contents of the Save Setup dialog box are as follows e Viewpoint A button that enables you to save the setup object in the design viewpoint container This feature allows you to keep specific setups with specific design viewpoints If you click on this button you must also provide a leafname for the setup object Pathname An entry box field that specifies the pathname to the setup object If you click on the Viewpoint button this entry box is not displayed Navigator A button that displays a file system navigator that you can use to inspect your file system If you click on the Viewpo
104. del type PATHD number of instances with Path Delays CONST number of instances with Timing Constraints defined and enabled MODEL TYPE COUNT PATHD CONST DEL 1 0 0 INV 5 0 0 REG 2 0 0 NET 12 0 0 SCHEMATIC 1 0 0 Compiled Model Info Count By Referenced Model COUNT MODEL TYPE MODEL PATHNAME 1 QPT user training qsim_n LATCH dff qpfile all N Gathering Toggle Statistics To measure how many times signals toggle between 1 and 0 you can gather toggle statistics Toggle statistics are useful in estimating how effective your functional verification stimulus will be for detecting manufacturing faults Valid toggle states are OS OR 1S and 1R Therefore a signal that transitions from OS to 1Z or from OS to XS has not toggled However a signal that transitions from OS to XS to 1R has toggled The following procedure describes how to gather toggle statistics 3 54 QuickSim II User s Manual V8 5_ 1 Operating Procedures Gathering Toggle Statistics 1 Select the desired nets buses or hierarchical instances You can verify that you have selected only the desired objects by looking at the highlighting in the displayed windows Although object selection is not required it is generally easier than specifying names of objects in the dialog box created in the next step 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Toggle Check The simu
105. des each signal pathname The following procedure describes how to generate toggle reports 1 Select the desired nets or buses 2 Choose the following pulldown menu path Menu Bar gt Report gt Toggle The simulator displays the Report Toggle dialog box which is shown in Figure 3 23 3 56 QuickSim II User s Manual V8 5_1 Operating Procedures Reporting Toggle Statistics Report Toggle On Selected objects Named objects Object name Type A amp N Either Vv Both Detail amount gt Short V One V Zero V Long V None 7V Any OK Reset Cancel Help Figure 3 23 Report Toggle Dialog Box 3 Make the appropriate choices from the dialog box as follows a Choose either the Selected objects button or the Named objects button from the top of the dialog box If you choose the Named objects button you must also complete the Object name entry box To report toggle statistics for the entire design you can specify a slash 7 in the Object name entry box b Click on the appropriate Type button to choose the flavor of toggle statistics that are reported The buttons and their corresponding types of toggle statistics are as follows e Either Reports statistics for nets that toggled to 1 or to 0 Default Both Reports statistics for nets that toggled both to 1 and to 0 QuickSim II User s Manual V8 5_1 3 57 Checking Device Stability Operating Procedures One Reports stati
106. design viewpoint and the back annotation object Unless the design changes are saved the version to which the simulation data applies is different than the version of the persistent design viewpoint and back annotation Non connectivity changes Most property changes such as changes to Rise and Fall properties do not affect design connectivity The exceptions are changes to Model properties and properties that are used in frame or Model property 2 44 QuickSim II User s Manual V8 5_1 Key Concepts Design Changes in QuickSim Il expressions When you make a change that does not alter design connectivity the following observations apply e The simulation time is not affected Although you can continue your simulation your results may be confusing depending on the nature of the change and the design being simulated For example any events that are pending when the change is made are scheduled using the old delay values Therefore you should use the Reset State command or the Menu Bar gt Run gt Reset pulldown menu item to reset simulation time to zero and initialize the design before continuing Windows that display signal activity such as Trace List and Monitor windows are not affected The data displayed in windows remains intact Connectivity changes The simulator always considers that the connectivity of the design is affected when you either reload a model or change the value of a Model property swap a model A
107. e Back tracing X States If your design is producing X signal states you can use the Debug Gates palette to find the instance that is generating the X state The BACKTRACE NETS X icon allows your to search back through a circuit for the cause of an X value To back trace X signal states perform the following steps 1 View the Debug Gates palette by clicking on the DEBUG GATES palette selection button 2 Select the net whose value is X Back tracing X states works best when only one net is selected With only one net selected you can focus on a single path 3 Click on the BACKTRACE NETS X icon The simulator examines the inputs of the instance that is driving the selected net If the signal value of any input to the instance is X the simulator selects the net attached to the input unselects the initially selected net and displays the following message in the Messages area Backtrace succeeded QuickSim II User s Manual V8 5_1 3 77 Changing the Design in QuickSim Il Operating Procedures You can then continue back tracing by clicking on the palette icon again If the simulator selects more than one input to the instance you may want to unselect all nets except one so that you can focus on a single path You can repeat the procedure to back trace the other paths If none of the inputs to the instance have a value of X the simulator does not unselect any nets and displays the following message in the Messages a
108. e You can update the models referenced by a set of selected instances The simulator checks all models used by those instances to see whether a new version exists and then updates any instances that use the changed models This scenario updates each instance that uses any model that the selected instances reference e You can update every model in the entire design This scenario updates every instance in the design that uses an outdated model version 2 46 QuickSim II User s Manual V8 5_1 Key Concepts Design Changes in QuickSim Il The simulator tracks model updates in the design viewpoint not in the back annotation object Swapping Models You swap models by editing the Model property on an instance by instance basis That is only the selected or specified instances are affected You can use this approach to change to an entirely different technology for some or all of your design For example changing a Model property might cause a QuickPart Table to be used in place of a sheet based model At the same time a new technology file might be brought in to the design To understand the potential of this approach you need to fully understand the modeling and registration process and how applications select a particular model For an overview of the digital modeling methods and process refer to the Digital Modeling Guide For information about how the simulator selects a particular model refer to Design Evaluation and Model
109. e General NONE posedge or negedge 01 or 10 OZ or Z1 or 1Z or ZO Not Falling posedge 01 NONE OZ or Z1 Not Rising negedge 10 NONE ZO or 1Z Rising 01 posedge NONE Falling 10 negedge NONE D 16 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation Table D 2 SDF Transition priority Technology File SDF priority list Transition Type To Hi Z UZ OZ or 1Z NONE From Hi Z ZU Z1 or ZO NONE ZL Z0 negedge NONE 10 ZH Z1 posedge NONE 01 LZ OZ posedge NONE 01 HZ 1Z negedge NONE 10 ZZ OZ or Z1 or 1Z or ZO NONE Example Statements may look like this in a Technology File tP 11 ON clk LH TO q WITH clir H tP 17 ON clk AH TO q WITH cir H tP 23 ON clk AA TO q WITH clir H The SDF statement below may annotate all three Technology File statements TOPATH clk g 17 11 23 17 23 11 But if the SDF statement below appears it will prevail over the one above for annotation of the top two Technology File statements because they are Rising and Not Falling edge types respectively and posedge take priority over no edge specifier NONE in their lists See Table D 2 IOPATH posedge clk g 18 11 23 17 23 11 And if the following SDF statement also appears it will prevail over both of those above to annotate the top Rising Technology File statement since 01 p
110. e Change Spike Warnings command or the Setup gt Kernel gt Change gt Spike Warnings pulldown menu item Technology File Configurable Spike Models The configurable spike model allows the modeler to specify three different regions in the period between the arrival of the previously scheduled output event and the arrival of the conflicting event The regions are suppress X pulse and transport These regions are specified using the Suppress_limit and X limit parameters within the Spike_model statement Figure 2 11 shows how these parameters define the three regions suppress limit x_limit total path delay Suppress X pulse Transport Region Region Region p 0 time after leading pulse edge Figure 2 11 Spike Pulse Propagation Regions Technology File configurable Spike Models support the following features e Technology file spike models take precedence over the simulator spike model but if no Technology File spike model is found the simulator model is used e Each signal path within the model can have a unique Spike_model definition including internal signals e An X IMMEDIATE directive within the Spike_model statement allows functionality identical to the X immediate model within QuickSim II e The MODEL_DEFAULT name allows a Spike_model statement to apply to all delays that do not explicitly use a Spike_model definition 2 28 QuickSim II User s Manual V8 5_1 Key Concepts Spike Models e The
111. e contents of the design viewpoint container You can click on an entry in the list box to specify the simulation state you want to restore o Enter a pathname in the Pathname entry box The default for this pathname is the current working directory with the leafname of quicksim_state o Click on the Navigator button and use the dialog navigator 3 70 QuickSim II User s Manual V8 5_1 Operating Procedures Using Breakpoints o Click on the Restore state button to restore disable confirming restore 3 Click on the OK button For more information about restoring the simulation state refer to the Restore State command in the SimView Common Simulation Reference Manual Using Breakpoints Breakpoints provide you with a powerful means to troubleshoot problems in your design You may use a number of conditions as breakpoints during the simulation in order to isolate specific problems Adding Breakpoints To add a breakpoint perform the following steps 1 Choose the following pulldown menu path Menu Bar gt Add gt Breakpoint The simulator displays the Add Breakpoint dialog box which is shown in Figure 3 29 QuickSim II User s Manual V8 5_1 3 71 Using Breakpoints Operating Procedures Add Breakpoint On Expression VHDL object Expression Jm On change On occurrence 1 m End of timestep Action list jm Stop simulation _ Delay actions m Filter redundant events OK Reset Cancel
112. e design viewpoint You can specify a leafname in the Leafname entry box or you can use the default which is guicksim_state 3 Ifa file at the specified location already exists you must click on the Replace button 4 Click on the OK button If the current design viewpoint is persistent exists on disk the simulator saves the simulation state at the specified location If the current design viewpoint is not persistent the simulator displays a message box and asks whether you want to save the design viewpoint QuickSim II User s Manual V8 5_1 3 69 Saving and Restoring Simulation States Operating Procedures 5 To allow the simulator to save the simulation state click on the Yes button to save the design viewpoint For more information about saving the simulation state refer to the Save State command in the SimView Common Simulation Reference Manual To restore a simulation state perform the following steps 1 Choose the following pulldown menu path Menu Bar gt File gt Restore gt State The simulator displays the Restore State dialog box shown in Figure 3 28 Restore State _ Viewpoint Pathname quicksim_state Navigator _ Restore state without confirmation OK Reset Cancel Help Figure 3 28 Restore State Dialog Box 2 Specify a saved simulation state by using one of the following methods o Click on the Viewpoint button The simulator displays a list box that shows th
113. e duration of the spike condition The duration of the spike condition equals the scheduled time of the new state minus the current simulation time If the new state has a delay of zero the X immediate state lasts for one timestep so that it will be visible in any record of the signal s activity 4 The simulator schedules the new state according to any associated delay The X immediate spike model can increase the number of events that the simulator must evaluate For simulations that produce Note many spikes the increase can adversely impact performance The simulator uses the following additional rules if the new state is the result of a tPX transition Remember that a tPX transition consists of one event that yields an X and a second event that completes the transition to the new state 2 26 e If the scheduled state is a tPX transition and the final states are identical the duration of the resulting X state begins with the earliest X state and lasts until the latest final state This produces a worst case handling of the spike This situation is shown in Figure 2 9 which shows two waveforms and identifies the duration of the resulting X state for both the suppress spike model and the X immediate spike model If both final states are not identical the simulator simply removes the scheduled tPX transition from the event queue and schedules the new tPX transition without adjusting the duration of the X state QuickSim II User
114. ected instances Named instances Spike model 4 X Immediate _ Override lt r Suppress OK Reset Cancel Help Figure 3 15 Change Spike Model Dialog Box 3 Make the appropriate choices from the dialog box as follows a Choose either the Selected instances button or the Named instances button from the top of the dialog box If you choose the Named instances button you must also complete the Instance name entry box b Click on the appropriate Spike model button For information about the spike models refer to Spike Models on page 2 24 c To override the spike model set at levels below the targeted instances click on the Override button Note that this button will not override lower level spike models that were also set with the Override button 4 Activate your choices by clicking the OK button at the bottom of the dialog box QuickSim II User s Manual V8 5_ 1 3 41 Checking for Spike Conditions Operating Procedures Checking for Spike Conditions You can enable the reporting of spike warning messages during a simulation run by enabling spike warnings If the simulator finds that a spike condition exists it generates a warning message citing the pins that are responsible and the conditions that caused the spike When you invoke the simulator you can enable spike warnings for the entire design Spike warning messages are all disabled by default If you want to change this global setti
115. eference one or more back annotation objects Back annotation objects contain changes to the design that were made in tools other than the Design Architect For example when you change a property within QuickSim II the change is added to the back annotation object You can create the technology and timing aspects of the design using models called technology files or linear technology files with which you can build sophisticated pin to pin timing delays and dependencies You create the component s graphical representation which is called a symbol using the Symbol Editor in the Design Architect You can use a variety of methods to create functional models each method you choose impacts the success of your design Table 2 1 lists the methods available for representing functional models For information about selecting the best modeling method for a given purpose refer to the Digital Modeling Guide Table 2 1 Functional Model Types Model Type Description of Design Data Object Behavioral Language The object file that results from your compiling a high Model BLM level language source file that describes a device Builtin Model An understanding of the device s logical behavior that is built into the QuickSim II analysis tool Logic Model LM The Shell Software and the physical device used with the LM Family hardware modelers QuickPart Schematic The object file that results from your compiling a Model sch
116. egin with word report from which you can then select and issue Quick help which is information that is displayed in a dialog box inside the session window For example quick help is available for commands and functions and consists of a brief functional description and a usage line Reference help which is information that is displayed using the BOLD Browser and the online INFORM documentation library Using reference help you can display pages from the Mentor Graphics manuals For example you can display the manual page where a specific command or function is described The following sections describe how to use these forms of online help Command Completion Command completion allows you to query the simulator for a list of commands that match a specified pattern From the resulting list you can select and issue the desired command Command completion can provide the following sets of commands e A set of commands whose first characters match a pattern For example you can obtain a list of all the commands that begin with the word report e A set of commands that match a wildcard pattern A wildcard pattern takes the form of m pattern where m are required literal characters and pattern is the set of characters you want to match QuickSim II User s Manual V8 5_1 3 15 Using the Online Helps Operating Procedures For example if you type m break the simulator displays the set of comma
117. ely click on the setup categories which are defined as 3 66 follows State If you select the State button the simulator removes from memory and discards all the data in the Results waveform database The simulator also removes this data from window displays Because the results data may be important the dialog box expands to give you the opportunity to save the information stored in the Results waveform database To discard the Results waveform database without saving the data ensure that the Save results Waveform DB button is not selected To save the Results waveform database perform the following steps a Click on the Save results Waveform DB button to select it QuickSim II User s Manual V8 5_ 1 Operating Procedures Saving and Restoring Simulation States b Specify a location by either specifying a pathname in the Pathname entry box clicking on the Navigator button and using the dialog navigator or selecting the Viewpoint button If you select the Viewpoint button the directory defaults to that of the design viewpoint and you must supply the leafname of the location c Ifa file at the specified location already exists you must select the Replace button For more information about resetting the kernel state refer to the description of the Reset State command in the Digital Simulators Reference Manual Setup If you select the Setup button the simulator closes all windows deletes action lists and
118. ematic with the QuickPart Schematic compiler QuickPart Table The object file that results from your compiling a Model QuickPart Table file which are ASCH files that describe the different states of a device based on its input and output pins Memory Table Model The object file that results from your compiling an ASCII interface file that describes the memory access control logic and actions of a memory array device QuickSim II User s Manual V8 5_ 1 2 3 Design Viewpoints and QuickSim Il Key Concepts Table 2 1 Functional Model Types Model Type Description of Design Data Object Schematic Model A schematic that you create with the Design Architect by instantiating and connecting various models VHDL Model The object files that result from your compiling with the Design Architect VHDL Editor Each occurrence or instance of a component on a schematic sheet can consist of a graphical model the symbol a functional model its logic behavior and a technology model process and implementation details When you create the component you must associate these different aspects if you want the simulator to use each aspect during a simulation By default the Design Architect and the various model compilers create the appropriate associations for you however you can explicitly associate models any way you want Because a component can have more than one version of each type of model you use labels to associate
119. entation a slash represents the QuickSim II User s Manual V8 5_1 2 7 Managing Designs Key Concepts root of the design Note that an error occurs if the root of the design is a primitive 2 If the current instance is not defined as a primitive and it contains hierarchy the simulator descends to the lower level and starts the process over However if the instance is not defined as a primitive and it does not contain hierarchy the simulator inserts a null model and starts the process over Null simulation models behave like an open circuit 3 Ifthe current instance is defined as a primitive the simulator gets the instance s Model property and attempts to match the value of the property to the labels that are registered in the component interface By order of precedence the simulator recognizes the following model specifiers Specific labels which are registered by users e Labels that reference builtin simulation primitives Default labels which are automatically registered by model compilers the Design Architect and other design creation applications 4 If the Model property matches a label and the model that the label references is valid for simulation the simulator builds the internal representation and starts the process over 5 If either the Model property does not match a registered label or the matched label does not reference a valid simulation model the simulator inserts a null simulation model
120. es Figure 2 8 shows a sample schematic and a Trace window that contains three waveforms This circuit feeds an input signal to two buffers which are described as follows e QuickPart Buffer A compiled QuickPart Schematic that uses a technology file to define its delay behavior The technology file defines the pin to pin rise and fall delays as 2 nanoseconds nS e Gen_lib Buffer A built in simulation primitive from the Mentor Graphics gen_lib library It uses Rise and Fall properties to define its delay behavior The Rise and Fall property values are displayed to the right of and below the symbol Both delays are 2 nS QuickPart Buffer IN TRANSPORT Gen_lib Buffer 2 INERTIAL TRANSPORT INERTIAL A I i Spike at Spike at o BO ns 6 0 8 0 Time ns Figure 2 8 Inertial and Transport Delay Modes 2 22 QuickSim II User s Manual V8 5_1 Key Concepts Delay Modes The Trace window in Figure 2 8 shows the traces for three signals e IN The primary input to the circuit which feeds the two buffers TRANSPORT The output from QuickPart Buffer which shows how the simulator treats pin to pin delays during the transport delay mode The transitions of this signal lag the transitions of the IN signal by 2 nS The simulator propagates every input transition to the output e INERTIAL T
121. es from the dialog box as follows a Choose either the Selected objects button or the Named objects button from the top of the dialog box 3 50 QuickSim II User s Manual V8 5_1 Operating Procedures Displaying Model Messages If you choose the Named instances button you must also complete the Instance name entry box To enable hazard checking for the entire design you can specify a slash in the Object name entry box b Click the On button to enable hazard checking c To override hazard checking set at levels below the targeted objects click on the Override button Note that this button will not override lower level hazard checking that was set with the Override button 4 Activate your choices by clicking the OK button at the bottom of the dialog box Displaying Model Messages You can design QuickPart Table models and Memory Table Models to generate messages when they encounter certain conditions during the simulation You can display these messages during the simulation run which can aid design debugging Simulator performance may degrade when the display of these messages is enabled The following procedure describes how to control the display of these messages 1 Select the desired instances Although instance selection is not required it is generally easier than specifying names of instances in the dialog box created in the next step 2 Choose the following pulldown menu path Menu Bar gt Setup
122. ess of the timing cache lock Changing Timing Mode Changing timing mode is allowed in QuickSim II but be aware of the timing data that has been calculated and or annotated for the QuickSim II session See the next section for more details Annotating Specific Timing Modes SDF supports the notion of triplets as does AMP It is therefore possible to annotate MIN TYP and MAX timing modes For example the follow SDF statement is generated to annotate a RISE prop of 1 2 3 and a FALL of 4 5 6 on output pin Q DEVICE Q 1 2 3 4 5 6 If only a single number is found in SDF DEVICE Q 2 5 only TYP will be annotated If any part of the design is in MIN or MAX mode it is not affected To target MIN or MAX timing data only use the triplet format and leave the unaffected mode fields blank For example to annotate only MIN values DEVICE Q 1 4 When a triplet is encountered in the SDF file the data for all modes is annotated to the timing cache only if the timing cache has been created in advance to contain those modes D 6 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation For example if the timing cache was constructed by QuickSim II which was invoked in MIN mode the timing cache will only contain MIN timing data slots and during a Load SDF File execution only the MIN timing data from the SDF file will be annotated even if the SDF file
123. expression definitions and resets all bus definitions synonyms probes groups and selection filters to their original settings For more information about resetting the setup refer to the description of the Reset Setup command in the SimView Common Simulation Reference Manual You can also specify that you do not want the Waveform DBs reset Saving and Restoring Simulation States You can save the current state of a simulation which you can then restore at a future time The simulation state consists of the data inside the kernel such as all scheduled events and the current state of all nets in the design This information allows you continue a simulation where you left off but does not restore setup information for the kernel or the user interface For information and procedures about setting up the simulator refer to the Setting Up QuickSim IT which begins on page 3 17 You must satisfy some prerequisites before you can save a simulation state They are as follows QuickSim II User s Manual V8 5_1 3 67 Saving and Restoring Simulation States Operating Procedures The simulator must be at a timestep boundary This is a concern only if you are simulating VHDL models Use the Step End command to reach a timestep boundary The current version of the design viewpoint must be persistent saved on disk Because of this requirement you must either save or discard the design changes you have made to that point in your simulati
124. expressions or evaluates breakpoints it uses the waveform data in the default waveform database unless the signal name is prefixed with the name of the waveform database in which it resides For example to specify the waveform named my_signal that resides in the Forces waveform database you would literally use forces my_signal The two at symbols tell the simulator to use the signal data in the specified waveform database e Waveform databases can be saved to disk The exception is the Stimulus waveform database which cannot be written to disk as a waveform database but can be saved as a logfile or a force file The saved data objects are versioned allowing you to manage them with the design e Waveform databases are the source for logfiles and force files You can translate any waveform database loaded in memory including the Results Stimulus or Forces waveform database For more information about creating and using waveform databases refer to the SimView Common Simulation User s Manual QuickSim II Initialization Process Before a simulation can begin the simulator must know the state of each instance in the design The simulator determines this by performing an initialization process This initialization process sets each instance to a known state QuickSim II User s Manual V8 5_1 2 39 QuickSim Il Initialization Process Key Concepts The simulator automatically initializes the design upon invocat
125. ferent uses Primitive An instance that is a termination point for evaluation Primitive instances must provide device functionality to the simulator Substitute A property name whose value is to be substituted for another property s value Visible property A property that is visible to DFI and netlisters The simulator can store the following related objects inside the design viewpoint container Save state object Contains a complete kernel state the values of all the nets and instances in the design at a specific point in simulation time You can restore a saved state to return the simulation to the point at which you saved the state Timing cache Contains design viewpoint specific timing information The timing cache is used only for full simulation timing it is not used for unit delay timing Once the timing cache has been created the simulator reuses it until the version of the design viewpoint or anything that the design viewpoint references changes QuickSim setup object Contains simulator setup conditions that you can restore Setup conditions include the kernel setup timing and delay mode design and hierarchical checking modes and settings and BLM checking the keep list the run setup and a list of breakpoint settings Sim View UI setup object Contains user interface setup conditions that you can restore including window positions and sizes bus names synonyms expressions and user loaded userware Wavef
126. fied design configuration rules for your design The basic process of using DVE to create a viewpoint for a simulation follows 1 Invoke DVE on the component either from an operating system shell or from the Design Manager QuickSim II User s Manual V8 5_ 1 3 3 Processing a Design For Simulation Operating Procedures 3 4 This step opens a viewpoint which is called default and a design configuration This design configuration is empty unless it already existed If DVE is already invoked but not on a component perform the following steps a Choose the following pulldown menu path Menu Bar gt File gt Open gt Design Viewpoint DVE displays the Open Design Viewpoint dialog box b Specify the desired component and the name of the design viewpoint in the dialog box You can type in names for both of these arguments or you can use the navigator If you use the navigator it automatically provides the names To open a specific design viewpoint other than the one currently opened perform the following steps a Close the design viewpoint that is currently opened by choosing the following popup menu path Menu Bar gt File gt Close Design Viewpoint b Open the desired design viewpoint by choosing the following popup menu path Menu Bar gt File gt Open gt Design Viewpoint c Specify the desired component and the name of the design viewpoint in the dialog box You can type in names for both of t
127. for unspecified timing paths Unspecified paths check Design or instance Enable unspecified path checking You want to check for hazard conditions Hazard check Design or instance Enable hazard checking You want to check for thoroughness of pin toggling QuickSim II User s Manual V8 5_ 1 Toggle check Design or instance Enable pin toggle checking 3 19 Setting Up QuickSim Il Operating Procedures You have considerable control over how you apply setup conditions to your design You can apply any setup items from Table 3 1 to the entire design Also you can apply some of the setup items to individual instances If an instance is hierarchical the setup item is also applied to the instance s lower levels If you have established a simulation setup that you wish to use again in the future you can save the setup conditions and then restore them in the future To set up the kernel for the entire design perform the following steps 1 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Analysis The simulator displays the Setup Analysis dialog box which is shown in Figure 3 4 Setup Analysis Timing mode Current Unit Delay Constraint Detail of Current timing mode Hidden Visible OK Reset Cancel Figure 3 4 Setup Analysis Dialog Box 2 To establish setup conditions for the entire design click on the Timing mode button th
128. from the GENERAL category are annotated 3 OZ and 1Z will annotate UZ or ZZ Z1 and ZO will annotate ZU or ZZ QuickSim II User s Manual V8 5_1 D 15 SDF Technology File Correlation SDF in QuickSim Il 4 Ifa match for OZ 1Z Z1 ZO is still not found it will annotate more general Technology File edges allowing the Z side to match with either A or T and the other side to match with A V T X U and the appropriate explicit level either H or L Also ZO and 1Z will annotate FA Z1 and OZ will annotate RI This allows ZO to annotate such edges as AA TL TV FA etc For example the following Technology File statement tP 1 2 3 ON clk AX TO q AX will be annotated by these SDF statements IOPATH posedge clk q 1 2 3 IOPATH negedge clk q 4 5 6 Only the second statement s data is delivered since it was last seen This added parsing complexity is in the interest of finding a best match for every SDF statement Resolving Multiple Edge Matches If more than one SDF statement matches a Technology File edge priority is determined by the Technology File transition type using the table below The first entries in the lists have priority over those that follow A tie will cause any COND statements to be checked for best fit If it is still a tie the last seen statement will prevail Table D 2 SDF Transition priority Technology File SDF priority list Transition Typ
129. fully specifies triplets of data Changing to a new timing mode in QuickSim II at any point in the hierarchy of the design adds the data slots needed for the new mode In order to annotate the new data slots the Load SDF File command needs to be issued following the Change Timing Mode command If you expect to change the timing mode in QuickSim II a timing cache with several or all timing modes should be created by running TimeBase with the desired mode flags min typ max prior to invoking QuickSim II This allows all needed timing data to be annotated with the initial Load SDF File command SDF Technology File Correlation Obviously good correlation between the edges in Technology File statements and the SDF delay and timing check statements of an instance is necessary to get the desired result The best case situation is when a Technology File is created from the template used by SDF or vice versa Modelers and third party SDF generators should be aware of this This section summarizes the rules and issues involved in correlating the statements found in an SDF file with those found in Technology Files of ASIC cells Correlating Instance Paths SDF in expects instance paths found in the INSTANCE statements of the SDF file to match pathnames found in the EDDM database Synonyms for names that have been defined in the viewpoint are not recognized and cannot be annotated The hierarchical delimiter may be defined using the SDF
130. gnal relationships Because many simulation models have pin to pin propagation delays and pin rise and fall delays the simulator must have a way to schedule signal state changes that may occur in the future 2 14 QuickSim II User s Manual V8 5_1 Key Concepts How QuickSim Il Processes Circuit Activity QuickSim II schedules all events current and future by using a timing wheel algorithm as shown in Figure 2 4 Future ii B More Events QuickSim Il Evaluation t Event List NNO l1 2 21 0 7654321 3 Slots One t timestep Mature Events Figure 2 4 Timing Wheel A timing wheel consists of slots Each slot holds all the events for one simulation timestep QuickSim II can schedule events in any of the slots The simulation time of each timestep defaults to 0 1nS but you can set it to any value you wish when you invoke the simulator Events in the slot for the current simulation time are considered mature The simulator processes all mature events and then evaluates all the instances that those events affect It then sequentially processes the slots as simulation time advances Figure 2 4 shows a conceptual timing wheel in which QuickSim II evaluates mature events from slot 3 and schedules future events in slots 8 13 and others QuickSim II reads the event list processes the mature events evaluates their logical effects on the circuit and then schedules resulting events according to any a
131. gns e VHDL models are exempted from the recognition checks Any VHDL model will be recognized and used All Mentor Graphics generic library MGC_GENLIB components will be recognized QuickSim FPGA also has a limit to the number of primitive instances that can be placed in the design This limit will allow large FPGA packages to be built and analyzed but will limit FPGA systems Use QuickSim II for simulating FPGA package systems If that limit is exceeded QuickSim FPGA aborts invocation and returns an error message indicating that the FPGA instance count has been exceeded Once invoked QuickSim FPGA allows full access to all QuickSim II SimView commands and features B 2 QuickSim II User s Manual V8 5_1 Appendix C QuickSim Il Environment Variables Introduction On invocation QuickSim II examines the shell environment for a number of variables that control the way the simulator operates These variables fall into the following categories Required If these variables are not present QuickSim II will not function Optional as needed These variables change the default operating mode to allow alternate data access or normal modes of operation Patch Used to address a specific problem and provide a work around solution until a permanent Table of Environment Variables The following table lists many of the environment variables that are recognized and used by the QuickSim II Vari
132. gure 3 15 Figure 3 16 Figure 3 17 Figure 3 18 Figure 3 19 Figure 3 20 Figure 3 21 Figure 3 22 Figure 3 23 Figure 3 24 Figure 3 25 Figure 3 26 Figure 3 27 Figure 3 28 Figure 3 29 Figure 3 30 Figure 3 31 Figure 3 32 Figure 3 33 Figure 3 34 Figure 3 35 Figure 3 36 Figure 3 37 Figure D 1 Figure D 2 Figure D 3 Figure D 4 LIST OF FIGURES continued Restore Setup Dialog Box Change Timing Mode Dialog Box Change Constraint Mode Dialog Box Change Constraint Mode Dialog Box Change Spike Model Dialog Box Change Spike Warnings Dialog Box Change Contention Model Dialog Box Change Contention Check Dialog Box Change Hazard Check Dialog Box Change Model Messages Dialog Box Report Model Statistics Dialog Box Change Toggle Check Dialog Box Report Toggle Dialog Box Change Stability Check Dialog Box Setup Palette Reset Dialog Box Save State Dialog Box Restore State Dialog Box Add Breakpoint Dialog Box VHDL Portion of Add Breakpoint Dialog Box Breakpoints Report Window Delete Breakpoints Dialog Box Reload Model Dialog Box Specifying a Model Change Model Dialog Box Change Properties Dialog Box Expanded Change Property Dialog Box___S 3 32 3 35 3 36 3 38 3 41 3 43 3 46 3 49 3 50 3 52 3 53 3 55 3 57 3 59 3 64 3 66 3 69 3 70 3 72 3 74 3 75 3 76 3 79 3 80 3 82 3 83 3 84 SDF Annotation Process D 4 Twelve to Six Rvalue Transform gt gt D 22 S
133. he block with the circular reference opening down on the block will cause DVE to display the same schematic that you just opened down from In fact you can keep selecting the same block and endlessly open down on it Each time you open down you will see the same schematic Once you have discovered the schematic in error you must replace it with the correct schematic It is possible that you might have only one component buried deep in a design hierarchy with a circular reference A 10 QuickSim II User s Manual V8 5_1 QuickSim II Troubl sineckSingCrash During Invoke with the Fault Recovery Window QuickSim Crash During Invoke with the Fault Recovery Window e Signal 4 Recovery Signal 4 messages can be caused by BLM problems e Signal 10 Recovery Signal 10 can be caused by various fatal conditions e Signal 11 Recovery Signal 11 can be caused by various fatal conditions e Signal 13 Error Message Signal 13 is most commonly caused by floating license failures QuickSim II User s Manual V8 5_1 A 11 Signal 4 Recovery QuickSim Il Troubleshooting Signal 4 Recovery If you suspect that your problem may be caused by BLMs the best approach is to null out the BLM models in your design viewpoint and then try re invoking QuickSim to see if the signal 4 message is eliminated General Instructions for nulling a Model TAN 6229 Suppose that you have a simulation that appears to be providing incorrect
134. he design database design viewpoint back annotations and other design objects that the simulator uses This database provides information to both the front end and the kernel QuickSim II Kernel Performs the actual simulation by analyzing the functional and timing models Waveform Databases WDBs Provides the stimulus to the design and holds the simulation results QuickSim II User s Manual V8 5_1 1 13 QuickSim II Overview Overview of QuickSim Il Input and Output Data Like most applications the QuickSim II simulator accepts and produces a variety of data Figure 1 5 shows a summary of the different kinds of input data that QuickSim II accepts Each data type is briefly described in the lists that follow cs BLMS Technology Waveform Graphic Save State ean seed Files Database Input Objects lt gt sa Logfile MISL File Environment Builtins Force File Variables QuickPart Schematics QuickPart gaben i Memory Table Models daie System 1076 Ga TE LM Family Teomalony y Setup and gt ap Linear i Back modelnles Technology Design Picture Annotation Files Viewpoint Objects Objects W y y y y y d QuickSim Il f Figure 1 5 QuickSim II Input As Figure 1 5 shows QuickSim II input can include the following kinds of data e Models Provide the functional and timing information used during the simulation and include the following elemen
135. he output from Gen_lib Buffer which shows how the simulator treats all delays during the inertial delay mode as well as property defined delays during the transport delay mode The circles at 3nS and 8 nS identify spike conditions The simulator is using the suppress spike model For information about the spike models refer to page 2 24 The following list describes how the transitions on the IN signal affect the INERTIAL signal a At 2 0 nS the simulator evaluates Gen_lib Buffer and schedules an event to occur on the INERTIAL signal in 2 nS At 3nS the simulator evaluates the Gen_lib Buffer and attempts to schedule the resulting event on the output This event causes a spike because an earlier event is still pending According to the suppress spike model the simulator removes the pending event from the queue and discards it Since the new event is a transition to 0 which is the current state of the INERTIAL signal the simulator does not schedule it At 5 nS the simulator schedules an event to occur in 2 nS on the INERTIAL signal At 7 nS the simulator schedules an event to occur in 2nS on the INERTIAL signal The simulator also processes the event that was scheduled in step 3 and changes the INERTIAL signal to a 1 At 8 nS the simulator evaluates Gen_lib Buffer and attempts to schedule the resulting event This event causes a spike because an earlier event is still pending According to the suppress spike model the Quic
136. he setup conditions are maintained The maintenance of these conditions allows you to immediately run another simulation For example you do not need to re create windows forces or hierarchical checking and mode settings e Ifa property is changed the Back Annotation window that is associated with the active back annotation object is automatically updated This window shows you the changes that currently exist in the active back annotation object For more information about back annotation objects see Back Annotation Objects and QuickSim IT on page 2 48 e Changes are highlighted If a visible property is changed on a currently viewed design item the new value is highlighted in red on color monitors Design status windows such as the Object or Parts List windows are not affected If you want status information that reflects the design change you must recreate these windows e Restoring an existing simulation state is not allowed Any simulation state that exists at the time you change the design becomes invalid However if you do not save the design changes by saving the design viewpoint you can still restore an existing simulation state as long as it matches the current version of the design viewpoint and back annotation object e Saving the simulation state is not allowed until you save the design changes The simulation data that is written must be associated with a specific persistent saved on disk version of the
137. here the pulse width of the spike was narrow enough that the device output does not make a change to state1 This is shown in Figure 2 13 suppress limit 4 lt gt x_limit 7 lt gt d1 13 q gt IN event1 scheduled at time t1 d1 event1 cancelled event2 scheduled if different than state0 OUT a A 0 ne Figure 2 13 Pulse in Suppress Region t2 t1 lt suppress limit In this case event which scheduled state1 is suppressed canceled The new event is scheduled for state2 if it differs from state In this example state2 is the QuickSim II User s Manual V8 5_1 2 31 Spike Models Key Concepts same as state0 so no event is scheduled at time t2 In the general case the output remains at state0 until time t2 d2 when it changes to state2 Pulse in the X pulse Region The spike is in the X pulse region if the pulse is greater that the SUPPRESS_LIMIT but less than the X_LIMIT This region is where the spike pulse is just wide enough that the device output may or may not change to a different state due to event1 Therefore an X pulse is output which indicates this uncertainty X Pulse State The spike model determines an X pulse state depending on the state transitions that cause the spike which is scheduled on the device For a device which is not affected by strength of input states and whose outputs always have a drive strength of strong the X pulse state will always be Xs since
138. hese arguments or you can use the navigator If you use the navigator it provides only the name of the component you must still type in the name of the desired design viewpoint Specify the default configuration for QuickSim II using the following pulldown menu path QuickSim II User s Manual V8 5_ 1 Operating Procedures Processing a Design For Simulation Menu Bar gt Setup gt Quick SIM Fault Path and Grade This default configuration which is identical to what QuickSim II generates when it creates a design viewpoint and configuration does the following e Adds the following visible properties to the design viewpoint DECAY FALL MODELCODE RISE DRIVE INIT MODELFILE PINTYPE DTIME MODEL NOFAULT TIMEFILE Defines the following Model property values as being primitives INV RES CSWOR FPLD_MODEL BUF NULL NMOS LATCH AND XFER PMOS REG OR RXFER CMOS GEN_QPT NAND PXFER NSW QPT NOR PRXFER CSW G5 XOR CXFER PSW HML XNOR CRXFER RAM BLM DEL WOR ROM LM BRES SWOR PLA MTM 5 Add the other parameter primitive definitions substitutions or insertions to the viewpoint using the Menu Bar gt Edit gt menu items 6 Close the design viewpoint using the following pulldown menu path Menu Bar gt File gt Close Design Viewpoint DVE displays a query box asking you to verify whether you want to save the changes 7 To save the design viewpoint click on the Yes button For detailed information about
139. iated with a palette icon click on the desired icon NOTE Some common command buttons and palette icons reveal a menu from which you must choose the desired action For information about the tasks and commands that each button and palette icon performs refer to Palettes in the SimView Common Simulation User s Manual Running the Simulator After you have applied stimulus to the design you can run the simulator One approach is to start the simulation by issuing the Run command You can specify a time which can be an absolute time or relative to the current simulation time If you do not specify a time the run template is used Resetting the Simulator You can restart a simulation by performing the following steps 1 Reset the simulator to time zero by choosing the following pulldown menu path Menu Bar gt Run gt Reset The simulator displays the Reset dialog box allows you to reset major areas of the simulator the State and the Setup The fully expanded Reset dialog box is shown in Figure 3 26 QuickSim II User s Manual V8 5_1 3 65 Resetting the Simulator Operating Procedures ic State i This option will reset the current simulation time back to zero and clear the results Waveform DB jm Save results Waveform DB __ Viewpoint Pathname Navigator _ Replace jm Setup __ Do NOT reset Waveform DBs Ok _Reset_ _Cancel Figure 3 26 Reset Dialog Box 2 Appropriat
140. ibutes warn_start Delay from abs time zero for each message type to begin displaying wdb_filters Waveform database filter definitions Add Wdb Filters wdb_info Pathnames wdb_info wdb and connections wdb_info conn to persistent waveform database plus the forces aux and asserts waveform databases window_attributes Default window attributes such as color font radix etc A file is saved for each window type Restoring Setup Conditions You can restore saved setup conditions if you want to return to a setup environment Each time you reset the simulator to time zero you can restore the setup You can also restore a setup when you invoke the simulator NOTE Even though the delay mode inertial or transport might be part of the setup data object it cannot be restored after the simulator is invoked To restore the delay mode invoke the simulator with the Setup switch and specify the setup object pathname To restore a setup during the simulation perform the following steps 1 Choose the following pulldown menu path Menu Bar gt File gt Restore gt Setup QuickSim II User s Manual V8 5_1 3 31 Restoring Setup Conditions Operating Procedures 3 32 The simulator displays the Restore Setup dialog box which is shown in Figure 3 11 Restore Setup _ Viewpoint Pathname quicksim_setup Navigator __ Restore setup without confir
141. ific setup condition click on the corresponding button or change the appropriate text entry box Click on the OK button QuickSim II User s Manual V8 5_ 1 Operating Procedures Setting Up QuickSim Il Setting Up Instance By Instance In addition to setting up the entire design for a simulation you can specify setup conditions for individual instances This is particularly useful when your analysis is focused at lower design levels The following list contains conditions that you can specify on an instance by instance basis Constraint mode Contention checking Contention model works only at the root of the design or on specific nets e Hazard checking Model message display e Spike warnings Spike model e Stability checking e Timing mode Toggle checking For example you might specify the default setup for the entire design which uses unit delay timing Then if you decide that you want to analyze timing behavior for a portion of the design you would perform the following steps 1 Select the instance or instances for which you want to enable timing 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Timing Mode The simulator then displays the Change Timing Mode dialog box which is shown in Figure 3 6 QuickSim II User s Manual V8 5_ 1 3 23 Setting Up QuickSim Il Operating Procedures Change Timing Mode On Selected instances Named instances
142. ign Architect to create components Once you have created the component you can move immediately into simulation The design viewpoint contains the configuration rules that define how the simulator perceives the component The design viewpoint is essential to simulation and other applications The configuration rules define design and expression parameters design viewpoint substitutions and visible properties They also define the instances in the design that are primitive 1 10 QuickSim II User s Manual V8 5_1 Overview of QuickSim Il QuickSim II Overview Primitives provide the functionality that the simulator uses Running DVE is optional because the simulator upon invoking creates a design viewpoint with a default configuration if one does not already exist You can create specialized design viewpoints using the Design Viewpoint Editor DVE e The TimeBase application calculates unscaled delay values from the information and equations provided in technology files You can use TimeBase when your design contains many complex timing equations The resulting data is cached in a data object and placed in the design viewpoint Having this cache of timing data available when you invoke the simulator can significantly reduce invocation time Running TimeBase is optional because the simulator automatically calculates timing if no pre existing timing cache is available e The QuickSim II simulator calculates the behavior of the elect
143. imulation procedures and hyperlinked lists of related procedures The audience for this manual is design engineers who use Mentor Graphics applications to analyze the performance and behavior of electronic circuitry models For related information about SimView UI which is the user interface for all Mentor Graphics simulators refer to the SimView Common Simulation User s Manual Before using this manual online you should be familiar with the BOLD Browser The chapters Overview of QuickSim IT and Key Concepts provide background information about QuickSim II and digital simulation The chapter Operating Procedures contains procedures for commonly performed tasks The chapter Operating Procedures Cross Index provides several lists of related procedures that are documented in other manuals and each procedure is a hyperlink to the corresponding section in the appropriate manual For information about the documentation conventions used in this manual refer to Mentor Graphics Documentation Conventions QuickSim II User s Manual V8 5_1 xiii Related Publications About This Manual Related Publications The following text and illustration lists the Mentor Graphics manuals that document all of the features used by simulation applications The manuals are divided into the following categories e Simulation Manuals page xvi these document individual simulation applications and closely related functionality that is
144. in amount of data settling time and the second event completes the transition to the new state The simulator uses the output pin s Drive property for the strength of the X portion and if the pin does not have a Drive property the strength is S Spike conditions can affect the duration of the X portion of a tPX transition and this effect is described following the spike model descriptions which are next 2 24 QuickSim II User s Manual V8 5_1 Key Concepts Spike Models Simulator Spike Models Two spike models are available suppress and X immediate The models differ in how a spike condition affects the state of the output Generally speaking the suppress model is an optimistic spike model because it assumes that the spike condition has no intermediate effect on the output On the other hand the X immediate model is considered pessimistic because under certain conditions it assumes that the spike condition immediately causes the output to assume a temporary state before its final state The simulator considers the following states when handling a spike condition Current state This is the current driving state of the pin Scheduled state This is the pending state that was already scheduled e New state This is the new state that is causing the spike condition X immediate state This is the temporary state that the simulator assigns to the output when using the X immediate spike model This state is not used
145. in v8 2_5 is v8 2_14 1 and is contained in patch P97 The scenarios causing Signal 10 failures are 1 2 5 6 VHDL coding problems Heavy use of reload model command more than 10 times for the same model Making major design changes and then attempting a reload model Designs containing global signals that are shorted through a netcon Designs where there is no underlying net to match the symbol pin Initialization problems with Netdelays The best solution for all of the above problems other than 1 is to install patch p97 For problem 1 the best solution is work on debugging your VHDL code Otherwise contact Mentor Graphics Customer Support at 1 800 547 4303 for assistance QuickSim II User s Manual V8 5_1 A 13 Signal 11 Recovery QuickSim Il Troubleshooting Signal 11 Recovery Signal 11 errors are generally related to corruption of the QuickSim environment for a variety of reasons Signal 11 errors have been found to occur the same reasons as Signal 10 The scenarios known to cause Signal 11 failures are 1 2 6 7 VHDL coding problems Global signals connectivity problems Designs where there is no underlying net to match the symbol pin Initialization problems with Netdelays Insufficient swap space to invoke QuickSim BLM coding problems General design corruption problems If your design contains BLMs or VHDL SYS1076 models the best approach is to null these models and reinvoke
146. int button the Navigator button is not displayed QuickSim II User s Manual V8 5_ 1 Operating Procedures Saving Setup Conditions Replace A button that allows you to overwrite an existing setup object Query when Waveform DBs have edits pending A button that only asks to save WDBs if edits have been made and not saved Save All System Setup Groups A button that hides or discloses the group selection portion of the dialog box The default for this button is enabled Figure 3 10 shows this button disabled which reveals the group section portion of the dialog box visible 2 Fill in the dialog box accordingly 3 Click on the OK button The simulator then creates the setup objects The following table lists the setup groups that you can save in QuickSim II and other applications and describes the objects that are saved in each group In the Type column S session O object W window Table 3 2 System Setup Groups Group Name Description actionpoints Actionpoint definitions assertions SimView waveform assertion definitions Breakpoint definitions buses i e j User defined buses O chart_windows al e e Open Chart windows and their W contained signals context ejo e j Naming context Default S waveform database and Force Target waveform database QuickSim II User s Manual V8 5_1 3 29 Saving Setup Conditions Operating Procedures G
147. ints and QuickSim IT on page 2 4 Optionally run the TimeBase application to calculate the design s timing values in batch mode before you invoke the simulator For information about the TimeBase application refer to the chapter Using TimeBase in the Technology File Development Manual Optionally invoke SimView which is a read only simulator SimView allows you to view the design and create and edit stimulus For information about SimView refer to the SimView Common Simulation User s Manual Invoke QuickSim II If you used DVE to create a design viewpoint you should specify the design viewpoint when you invoke the simulator Otherwise the simulator invokes on a design viewpoint that defines default configuration rules and it creates it in memory if it does not already exist The typical strategy for simulation is an iterative process that has three main phases verify functionality without regard for timing verify functionality according to timing effects and verify functionality once the design is integrated into a higher level system Although the focus of each phase is different the tasks that you perform within the simulator are very similar The typical flow within the QuickSim II application is as follows a Set up the simulation environment The simulation environment consists of things such as the user interface breakpoints for debugging timing mode circuit violation checks and the signal data that you want
148. ion as well as whenever the Reset State command is issued Also to initialize the design at any time during a simulation you can use the Initialize command You may also want to suppress warnings and violation actions during the initialization process The Change Warning Start command allows you to suppress any or all of the checks or actions for a specified grace period There are two forms of initialization default initialization which is always performed when the simulator invokes and classic initialization Both forms of initialization set each instance in the design to a know state The major difference is that for the default initialization the simulator evaluates the instances only once while classic initialization involves repeated instance evaluations Another difference in the default initialization is that the simulator schedules new states according to the associated delay instead of using zero for the delay as with classic initialization The default initialization scheme is compatible with System 1076 models For compatibility with previous versions of the simulator you can perform classic initialization Both methods are described in the following sections Default Initialization With default initialization the simulator evaluates each instance once and schedules the resulting events according to any associated delays The result is similar to a power up for an electronic device This style of initialization must
149. ion 1 0 syntax is primarily a subset of V2 1 with the following exceptions that affect SDF in e The syntax for specifying conditions COND for timing checks was changed in V2 0 Both versions of this syntax will be allowed Examples COND clir SETUP data posedge clk 1 0 Version 1 0 SDF SETUP data COND clr posedge clk 1 0 Version 2 0 2 1 SDF Nested COND statements in the 1 0 version e g COND set COND clr SETUP lt etc gt will not be supported Version 1 0 statements USERDEF and INCLUDE were dropped in v2 0 and will not be supported in SDF in e Instance path dividers will be restricted to and as specified in v2 0 V1 0 allowed any character except V The Annotation Process Setting the Time Scale The SDF file may specify a time scale which sets the units for the data found in it QuickSim II correctly converts the data to timesteps its internal discrete timing units as it does for all timing data Delay scale which adjusts all timing by multiplier is ignored QuickSim II has its own delay scale implemented in the kernel Defining Timing Models Technology Files still play a role SDF is used in QuickSim II specifically to annotate timing data for delays and constraint checks It does not eliminate the role of AMP Technology Files as timing models in library components Constraint actions such as set state and send message directives exist only in the AM
150. ion are often caused by the lack of an available QuickSim license This can also happen if you have a VHDL model or BLM with an internal infinite loop If you have ruled out license and VLDL BLM problems and QuickSim only hangs on a specific design it is possible that your design contains circular references A circular reference can be created by saving the schematic that contains a symbol to the component interface that contains that same symbol lt p gt Circular references are not easy to identify MGC applications are likely to hang crash or provide no useful information QuickSim will hang or eventually crash with a memory fault or an illegal instruction TimeBase will also hang DVE will hang if you perform a Check Design DA will pass Check Sheet and Check Schematic CIB will be able to resolve model interface references as will the command listref Running a DMGR Check References with traversal on will also pass since the problem is not caused by a broken reference EXAMPLE Suppose you create a symbol called test and save it Later you place the symbol test on a schematic and connect nets to the symbol such that the nets have names that match those on the symbol pins then you save the design as test_des Before running your simulation on test_des you decide to create a schematic for test You open the schematic of test_des and save it as test When you invoke QuickSim on te
151. ironment Memory Table Model Development Manual contains information that helps you develop Memory Table Models which specify the functionality of a memory device s pins Properties Reference Manual contains comprehensive information about Mentor Graphics design properties which are used by many Mentor Graphics products including all simulation applications QuickPart Schematic Model Development Manual contains information that helps you develop QuickPart Schematic models These types of models are based on a compiled schematic QuickPart Table Model Development Manual contains information that helps you develop QuickPart Table models These types of models are based on ASCII truth tables System 1076 Design and Model Development Manual provides concepts procedures and techniques for using VHDL within the System 1076 environment Technology File Development Manual explains the use of technology files to aid in the modeling of electronic parts and components This manual provides detailed reference information about technology file statements usage information and a tutorial Falcon Framework Manuals AMPLE User s Manual describes how to use the Mentor Graphics AMPLE language This manual contains flow diagram descriptions and explanations of important concepts and shows how to write AMPLE functions BOLD Browser User s Manual explains basic BOLD Browser operations such as searching for a phrase in the INFORM library using the
152. isplays present waveform values and signal relationships and cross window highlighting quickly leads you to objects of interest You can save the results data to analyze later or to compare with other results e Optionally modify the design If you find a problem with the design or you want to use an updated model you can bring the changes directly into the simulator without exiting first For example you can change and recompile a VHDL model using the capabilities in the Design Architect reload the model in the simulator and then continue with your simulation without exiting and re invoking the simulator QuickSim II User s Manual V8 5_ 1 1 9 QuickSim II Overview Overview of QuickSim Il QuickSim II Data Flow The data flow for QuickSim II involves several design data objects and several applications Figure 1 3 shows the data flow for QuickSim II a ee 2 Models Design Architect Electronic Design 0 Back Annotation Waveform 3 Databases Design f Viewpoint QuickSim Il Component SimView UI TimeBase Figure 1 3 QuickSim Il Data Flow QuickSim Il Kernel QuickSim II simulates electronic designs and the first stage of the design flow is to create a piece of the design called a component The component consists of the logical graphical timing and technology aspects of the design You can use the schematic symbol and VHDL editing capabilities of the Des
153. it is selected QuickSim II User s Manual V8 5_1 3 7 Invoking QuickSim Il Operating Procedures 3 8 b Position the mouse pointer in the navigator window and choose the following popup menu item navigator gt Open gt QuickSimll You should see the Design Manager create a new shell for the QuickSim II application NOTE When you invoke the simulator from the Design Manager s navigator window the simulator automatically uses all default values for the initial setup conditions To specify initial setup conditions you must invoke the simulator either from the Tools window or by using the quicksim shell command For specific information about the invocation switches and the setup conditions they apply refer to the Digital Simulator s Reference Manual To invoke the simulator from the Design Manager s Tools window perform the following steps a Click on the QuickSimlII icon to select it The Design Manager should highlight the icon to indicate that it is selected b Position the mouse pointer in the Tools window and choose the following popup menu item Tools gt Open You should see the Design Manager display the QuickSim II dialog box which allows you to specify the design and the initial setup conditions for the simulation The expanded form of the QuickSim II dialog box is shown in Figure 3 2 c To expand the dialog box to the size shown in Figure 3 2 click on the Delay button first and then click
154. iving these statements must be primitive instances with Technology Files e All of the above statements allow a COND conditional clause that maps to a WITH clause in the Technology File statement e There is not an SDF statement analogous to the Technology File s MIN statement Therefore this data cannot be annotated Forward Annotation Constraints Not Supported There is a special class of statements that may appear in SDF TIMINGCHECKS PATHCONSTRAINT SUM DIFF SKEWCONSTRAINT and CORRELATION statements are meant for forward annotation to other tools such as layout and synthesis and are not meaningful in simulation They will be parsed and ignored Correlating SDF COND and Technology File WITH conditions If the SDF Technology File pair being checked have conditional expressions they must be also pass a correlation test An SDF COND will be considered a fit for a Technology File statement s WITH clause if none of the product terms of the COND expression contradict the WITH statement If more than one SDF statement fits a Technology File statement a best fit algorithm is used No COND in an SDF statement by definition means all conditions and will fit all Technology File edges regardless of the existence of a WITH clause if other elements are correlated Example Given a Technology File statement D 12 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation tP 1
155. ix to Three Rvalue Transform gt gt gt gt _ _7 _ D 23 Six to Two Rvalue Transform gt gt gt D 23 QuickSim II User s Manual V8 5_1 Table of Contents LIST OF TABLES Table 2 1 Functional Model Types B Table 2 2 Simulation State Values gt 2 10 Table 2 3 QuickSim II Node Resolution 2 12 Table 3 1 Circumstances that Suggest a Custom Setup 3 19 Table 3 2 System Setup Groups 8 29 Table 4 1 Operating Procedures in the SimView Common Simulation User s Manual ______ MA Table 4 2 Operating Procedures that are found in the Design Viewing and Analysis Support Manual __ SSCS 3 Table 4 3 Operating Procedures that are found in the Design Viewpoint Editor User s and Reference Manual SSS AF S Table C 1 I Table D 1 Mapping SDF Edge Specifiers SSCS 15 Table D 2 SDF Transition priority SCS 16 Table D 3 Technology File to SDF 12 Value Data Field ___ CSCSCSCSC 19 QuickSim II User s Manual V8 5_1 xi Table of Contents LIST OF TABLES continued QuickSim II User s Manual V8 5 1 About This Manual About This Manual This manual explains how to use the QuickSim II application QuickSim II is an interactive logic simulator that allows you to verify Mentor Graphics electronic designs This manual provides background information various s
156. kSim II User s Manual V8 5_1 2 23 Spike Models Key Concepts simulator removes the pending event from the queue and discards it Since the new event is a transition to 1 which is the current state of the INERTIAL signal the simulator does not schedule it f At9nS the simulator schedules an event to occur in 2 nS on the INERTIAL signal g At 11 nS the simulator schedules an event to occur in 2 nS on the INERTIAL signal The simulator also processes the event that was scheduled in step 6 and changes the INERTIAL signal to a 0 h At 13 nS the simulator processes the event that was scheduled in step 7 and changes the INERTIAL signal to a 1 Spike Models Conditions that Cause a Spike For all instances that use the inertial delay mode spike models instruct the simulator in how to handle spike conditions A spike occurs when the simulator tries to schedule an event on a pin that has an event of a different value already scheduled This can happen when an input signal changes state during the delay period of a previous state change An event usually causes the signal to transition once from the present state to the new state However when tPX X delay statements are used in technology files there is a case where one transition consists of two events tPX statements define a period of time where the signal value is invalid unknown and are typically used with memory devices The first event sets the signal to X for a certa
157. kSim Il Table 3 1 Circumstances that Suggest a Custom Setup Circumstance Design contains zero delay feedback loops Setup Item Iteration limit Design Suggested Setup Action Set iteration limits for initialization and run time VHDL models have assertions set VHDL assertion severity level Design Set the level where VHDL assertions stop the simulator VHDL models have signals specified as arrays VHDL array size Design Set the number of array elements that Examine Objects shows You are debugging design logic Timing mode Design or instance Select the unit timing mode You are debugging the effects of timing on logic Timing mode Design or instance Select the minimum typical or maximum timing mode You are debugging design logic according to technology file defined constraints Timing and Constraint modes Design or instance Select the timing mode and enable constraint checking Design contains nets with multiple drivers Net Contention Design or instance Enable contention checking You want to check the simulation for spike conditions Spike model and spike check Design or instance Specify the desired spike model and enable spike checking Design contains models that generate messages Quickpart messages Design or instance Enable the display of model generated messages You want to check technology files
158. l 10 failures are ____ SS SCSCSCS lt PUA KI Signal 11 Recovery A 4 vi QuickSim II User s Manual V8 5_1 Table of Contents TABLE OF CONTENTS continued The scenarios known to cause Signal 11 failures are A 14 Signal 13 Error Message gt gt Z A 5 Symptom Memory Fault A 16 Error Messages Issued___ A 17 Cannot Connect to Child A 18 Too Many Net Recursions____ A199 Parameter Undefined TSUD gt A 200 QuickSim Issues Warning Message on Invoke _A 21 QuickSim NULLs Model on Invoke A 222 QuickSim Loads Wrong Models on Invoke _ A 223 QuickSim Runs Out of Memory During Invoke A 4 Symptom QuickSim Fails After Invocation _A 25 Quicksim crashes during run_____SS A 26 Quicksim crashes with reload model gt gt gt S A 2 Quicksim crashes with reset OA 28 Quicksim crashes with initialize__ SSSA 29 Quicksim crashes on AMPLE execution____SSSSSSSSOSFSSSSSSSS CFFFFFFSSSSSSSCFFSCA 30 Quicksim hangs during run A 3 Quicksim hangs with command execution A 322 Quicksim hangs with AMPLE execution A 33 Quicksim runs out of memory during simulation run____ C A 34 Appendix B Invocation of QuickSim II for FPGAstation gt B l Introduction CBI Description of Functionality___ SSSSSSSSSS
159. lator displays the Change Toggle Check dialog box which is shown in Figure 3 22 Change Toggle Check On Selected Objects Named objects Object name Toggle check A ofi Override C2 OK Reset Cancel Help Figure 3 22 Change Toggle Check Dialog Box 3 Make the appropriate choices from the dialog box as follows a Choose either the Selected objects button or the Named objects button from the top of the dialog box If you choose the Named objects button you must also complete the Object name entry box To apply the contention model to the entire design you can specify a slash in the Object name entry box QuickSim II User s Manual V8 5_1 3 55 Reporting Toggle Statistics Operating Procedures b Click the On button to enable toggle statistic gathering c To override the toggle checking set at levels below the selected or specified objects click on the Override button Note that this button will not override lower level toggle checking that was also set with the Override button 4 Activate your choices by clicking the OK button Reporting Toggle Statistics After the simulator has gathered toggle statistics you can view a report of them by creating the Toggle Summary or Toggle Report windows The Toggle Summary window contains a short Summary account of toggle statistics The Toggle Report window contains a long signal by signal account of the toggle statistics and inclu
160. lement in AMP WITH expressions and are ignored See Correlating SDF COND and Technology File WITH conditions on page D 12 There is no syntax in V2 1 SDF analogous to TPX or TPXB Therefore annotated data from SDF IOPATH statements will only annotate the valid time the second data field in the TPX statement V3 0 SDF will add syntax for this feature PATHPULSE and GLOBALPATHPULSE which map to SPIKE_MODELs is not supported in this release TIMINGCHECK statements are SETUP maps to a Technology File SETUP tS or the setup first field of a tSTAB statement HOLD maps to a Technology File HOLD tH or the hold second field of a stability tSTAB statement SETUPHOLD maps to STAB tSTAB or to separate SETUP and HOLD statements RECOVERY maps to a Technology File ASETUP statement or an AHOLD with the pin order reversed If neither is found a SETUP or HOLD statement may be used if the pins match and it is not annotated by an actual SETUP or HOLD SDF statement NOCHANGE maps to a STAB with a state or a double transition on the to pin Examples tSTAB 23 31 ON data TO clk LH HL tSTAB 37 41 ON data H TO clk H QuickSim II User s Manual V8 5_1 D 11 SDF Technology File Correlation SDF in QuickSim Il e SKEW maps to Technology File SKEW e WIDTH maps to Technology Files WIDTH tW e PERIOD maps to Technology File fMAX Where 1000 PERIOD ns fMAX Megahertz Notes e Instances rece
161. licitly keep the pin direction of IN if waveform information for both directions is desired SDF in QuickSim Il Quicksim is enhanced to allow annotation to AMP timing models of calculated timing values through the Standard Delay File SDF format which has become an industry standard maintained by Open Verilog International OVD Support of SDF means support of third party timing calculators and various other tools that annotate timing values during the design process Several vendors have in house golden timing calculators which they prefer for sign off simulation Other tools are specialized for adding post layout timing accuracy The QuickSim Load SDF File Command To meet these timing goals you are allowed to annotate QuickSim II s timing cache directly Once QuickSim II is invoked in min typ or max timing mode a timing cache exists that can be annotated using a new command from within QuickSim II the Load SDF File command The syntax of this command is found in the Load SDF File section of the Digital Simulators Reference Manual 2 50 QuickSim II User s Manual V8 5_1 Key Concepts SDF in QuickSim Il Multiple Load SDF File commands may be given in a QuickSim session The last annotation of any given datum will prevail unless the INCREMENT directive is used in the SDF file in which case the SDF values are added to existing values A pop up form for issuing this command will be added to QuickSim userware for use
162. lity 3 58 Command completion 3 15 Commands querying the simulator for 3 15 Common simulation interface procedures 4 1 Common user interface manuals list of titles xvii Component overview 2 4 Concepts key 2 2 Connecting WDB s procedure 4 2 Connectivity and QuickSim II 2 16 Connectivity design changes 2 45 QuickSim II User s Manual V8 5_1 Constraints procedure for checking 3 37 Contention model procedure for changing 3 44 Contention calculating results 2 11 Contention procedure for checking 3 48 Creating DVE script procedure 4 5 CTRL 3 15 CTRL S 3 14 D Delay modes 2 21 Delays Scheduling in QuickSim 2 18 Delays scaling for QuickSim II 2 21 Delete Breakpoints command operating procedure 3 76 Design changing concepts 2 42 effects of changing 2 43 overview of 2 2 processing for simulation procedure 3 3 properties and simulation 2 9 Design configuration Exporting 4 5 Design constraints procedure for checking 3 37 Design Manager invoking QuickSim II from 3 6 Design viewpoint associated QuickSim II data objects 2 5 creating procedure 3 3 default properties 3 5 overview of 2 4 primitives 3 5 Design Viewpoint Editor and simulation 3 3 Dialog boxes procedure 4 1 Disconnecting WDB s procedure 4 2 Displaying QuickPart messages procedure 3 51 Index 1 Index INDEX continued Drive strengths 2 9 DVE procedures 4 3 E Edit Exporting a design configuratio
163. low simulator performance If you use the Window switch you can keep a moving window of signal history where only a limited amount of the most recent signal history is kept Using windowed keeps can reduce the total amount of information being kept and thus maintain a high level of simulator performance Also information in a windowed keep is maintained within the kernel instead of the Results waveform database until the signal is displayed Maintaining this data in the kernel also improves performance For more information about adding signals to the keep list refer to the Add Keeps command and the Designating Waveform Data to Keep procedure in the SimView Common Simulation User s Manual To view a list of the signals that the simulator is keeping you issue the Report Keeps command which brings up the Keeps report window This window lists the signals currently being kept including signals in windowed keeps It also shows why each signal is being kept and whether it is an implicit or explicit keep For more information refer to the Report Keeps command in the SimView Common Simulation Reference Manual To remove a signal from the keep list you must explicitly delete it using the menus or the Delete Keeps command even if the signal was added implicitly For example if you display a signal in a Trace window it is implicitly added to the keep list If you then remove the signal from the Trace window the signal
164. lowing text describes the type of circuit activity that the simulator processes and demonstrates how it schedules the activity for processing QuickSim II User s Manual V8 5_1 2 13 How QuickSim II Processes Circuit Activity Key Concepts The discussion begins with some basic concepts and then covers the detailed scheduling algorithm What is Circuit Activity The basic circuit activity that the simulator processes is called an event An event occurs when a signal s state changes either the logic value or the drive strength which can be caused by a component s output or by input stimulus that you provide to the design Figure 2 3 illustrates a simple example of two events QuickSim Il 7 Evaluates e w Buffer Mature Event Event Scheduled t t 7 IN OUT 7 9 Figure 2 3 Simple Events As shown in Figure 2 3 the input to the buffer changes from low to high causing the simulator to schedule an event The event is like a flag that tells the simulator it must evaluate the buffer The simulator evaluates the buffer according to the new input state and propagates the newly evaluated state of the buffer to its output resulting in another event When the simulator processes this last event it typically fans out the resulting value to components that are connected to the output The Timing Wheel Accurate simulation requires the ability to simulate state changes at a specific time and to model complex si
165. lso changes to properties that are used in frame expressions or Model property expressions affect design connectivity The extent to which the design is affected is related to what the model is connected to and to the position of the model in the design hierarchy The farther down in the hierarchy the less the design is affected To maintain a reliable simulation the simulator behaves in a worst case manner when deciding the extent of change to the connectivity of the design When you make a change to the design connectivity the following additional behaviors apply e Source view windows are updated The schematic view and VHDL View windows automatically reflect the new model versions This behavior might delete an entire schematic view or VHDL View window if it contains data that does not exist in the new version As an alternative to deleting VHDL View windows you can instruct the simulator to merely line it out e The simulation time is automatically reset to zero This reset clears all report window displays and re initializes the design e Signal names in the keep list and the Forces waveform database are verified Signal names are invalid when the signal they refer to is no longer QuickSim II User s Manual V8 5_1 2 45 Design Changes in QuickSim Il Key Concepts in the design If any signal names are found to be invalid any stimulus being applied to them is disconnected although their waveforms remain in their respective
166. mation __ Do NOT restore WDBs _ Restore All System Setup Groups Specify any combination of System User defined or Other setup groups to restore User defined setup groups A Other setup groups Defined in saved object Group This supercedes manual group selection System setup groups actionpoints assertions breakpoints buses chart_windows context cycles expressions hdl_setup hier_modes keeps list_windows model_load monitor_flags monitor_windows OK Reset Cancel Help Figure 3 11 Restore Setup Dialog Box The contents of the Restore Setup dialog box are as follows e Viewpoint A button that enables you to restore the setup object from the design viewpoint directory This feature allows you to keep specific setups with specific design viewpoints If you click on this button the simulator lists the contents of the design viewpoint container from which you can make your choice QuickSim II User s Manual V8 5_ 1 Operating Procedures Setting Timing Modes e Pathname An input field that specifies the pathname for the setup object The default pathname is guicksim_setup If you click on the Viewpoint button the Pathname entry box is not displayed e Navigator A button that displays a file system navigator that you can use to inspect your file system If you click on the Viewpoint button the Navigator button is not displayed Restore setup without confirmation Do NO
167. n 4 5 Electronic designs overview of 2 2 Environment Variable AMPLE_PATH C 1 LANG C 1 LM_LICENSE_FILE C 1 MGC C 2 MGC_HOME C 1 MGC_LOCATION_MAP C 2 MGC_QSIM_GLOBAL_NET_SHORT C 2 MGC_SHOW_INT_TMG C 2 MGC_WD C 2 MGLS_LICENSE_FILE C 2 Environment Variables C 1 Event example of a simple 2 14 Events mature 2 15 Events scheduling 2 18 Examples Iteration 2 18 Resolving node contention 2 11 Scheduling events 2 18 Simple events 2 14 Timing wheel 2 15 Exiting the simulator 3 13 F Force file description 3 62 Forces WDB 2 38 Forces description 3 62 Frames determining object names procedure 4 4 Framework manuals list of titles xvii Index 2 H Hazards procedure for checking 3 49 Help procedures 4 1 Helps 3 15 command completion 3 15 using on line 3 15 High impedance Z drive strength 2 9 I Incremental design changes concepts 2 42 Indeterminate I drive strength 2 9 Inertial delay mode 2 21 Initialization classic 2 41 default 2 40 Input data QuickSim II 1 14 Invoking the simulator 3 6 Iteration example of 2 18 Iteration explanation of 2 15 K Keep list 3 60 Keeps behavior 3 60 Kernel setting up procedure 3 18 Key concepts 2 2 L Linear timing modes concept 2 19 Logfile description 3 62 Logic values 2 9 M Manuals list of titles Framework xvii Modeling xvi Simulation xvi Mature events 2 15 MISL file description 3 62 Model property
168. n any net bus or hierarchical instance The following procedure describes how to control contention checking 1 Select the desired net bus or hierarchical instance You can verify that you have selected only the desired objects by looking at the highlighting in the displayed windows Although object selection is not required it is generally easier than specifying names of objects in the dialog box created in the next step 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Contention Check The simulator displays the Change Contention Check dialog box which is shown in Figure 3 18 3 48 QuickSim II User s Manual V8 5_1 Operating Procedures Checking for Hazard Conditions Change Contention Check On Selected objects Named objects Contention check gt Off _ Override L n OK Reset Cancel Help Figure 3 18 Change Contention Check Dialog Box 3 Make the appropriate choices from the dialog box as follows a Choose either the Selected objects button or the Named objects button from the top of the dialog box If you choose the Named objects button you must also complete the Object name entry box To enable contention checking for the entire design you can specify a slash in the Object name entry box b Click the On button to enable contention checking c To override contention checking set at levels below the targeted objects
169. nce By Instance 3 23 Initializing the Design 3 24 Suppressing Initialization Warnings 3 25 Saving Setup Conditions 3 27 Restoring Setup Conditions ___ 3 3 1 Setting Timing Modes ___ 3 33 Loading an SDF File 3 36 QuickSim II User s Manual V8 5_ 1 3 1 Operating Procedures Checking for Design Constraints Changing the Spike Model Checking for Spike Conditions Changing the Contention Model Checking for Contention Checking for Hazard Conditions Displaying Model Messages Reporting Model Statistics Gathering Toggle Statistics Reporting Toggle Statistics Checking Device Stability Keeping Circuit Activity Applying Stimulus to a Simulation Using the Palettes Running the Simulator Resetting the Simulator Saving and Restoring Simulation States Using Breakpoints Adding Breakpoints Reporting Breakpoints Deleting Breakpoints Back tracing X States Changing the Design in QuickSim II Reloading A Model Writing Property Changes to a Specific Back Annotation Object Swapping A Model Changing A Property 3 2 QuickSim II User s Manual 3 37 3 39 3 42 3 44 3 48 3 49 3 51 3 52 3 54 3 56 3 58 3 60 3 62 3 64 3 65 3 65 3 67 3 71 3 71 3 75 3 76 3 77 3 78 3 78 3 80 3 81 3 83 V8 5_1 Operating Procedures Processing a Design For Simulation Chapter 4 Operating Procedures Cross Index contains lists of procedures that are documented in other manuals
170. nds that contain the characters break The set of commands for this example is Add Breakpoint Delete Breakpoint and Report Breakpoint e A complete set of commands that can be issued from within the currently activated window This feature requires that you specify a pattern of To use command completion perform the following steps 1 Type the pattern you wish to match 2 Press Ctrl Shift The simulator displays the commands that match the specified pattern 3 Click on the desired command to select it 4 Click on the OK button to issue the selected command The simulator displays the prompt bar or dialog box associated with the selected command 5 Fill in the information to complete the dialog box or prompt bar 6 Click on the OK button For more information about command completion refer to Command Completion in the Common User Interface Manual Quick Help Quick help is information that is displayed inside the application window The simulator offers the following primary categories of quick help e Version 8 commands and functions e Pre version 8 commands and functions e Palettes 3 16 QuickSim II User s Manual V8 5_1 Operating Procedures Setting Up QuickSim Il e Strokes e AMPLE scopes The primary method of accessing quick help is through the Help pulldown menu For specific procedures on quick help refer to Getting Quick Help in the SimView Common Simulation User s Manual
171. ng you can enable or disable spike warnings at any level in the design The setting that you make at one level propagates to lower levels unless you make another setting at a lower level You can enable or disable spike warnings for any instance in the design The following procedure describes how to control spike message reporting 1 Select the desired instance or instances You can verify that you have selected only the desired instances by looking at the highlighting in the displayed windows Although instance selection is not required it is generally easier than specifying names of instances in the dialog box created in the next step 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Spike Warnings The simulator displays the Change Spike Warnings dialog box which is shown in Figure 3 16 3 42 QuickSim II User s Manual V8 5_1 Operating Procedures Checking for Spike Conditions Change Spike Warnings On Selected instances Named instances Spike warnings to display __ Suppress _ Transport _ Override EX Display All Warnings OK Reset Cancel Help Figure 3 16 Change Spike Warnings Dialog Box 3 Make the appropriate choices from the dialog box as follows a Choose either the Selected instances button or the Named instances button from the top of the dialog box If you choose the Named instances button you must also complete the Instance n
172. ning messages enter a value in the Time entry box If you determine that short transient periods of contention are not important to debug you can set the grace period so the simulator ignores brief contentions QuickSim II User s Manual V8 5_ 1 Operating Procedures Changing the Contention Model c Click on the appropriate Model button as follows None Assigns no contention model to the targeted nets Any Contention occurs when a targeted net is driven by two or more pins regardless of their logic values For example two drivers on the same net with 1S and 1S states would be in contention The states IR and OS would also be in contention Same Contention occurs when a targeted net is driven by two or more pins that have the same logic value For example two drivers on the same net with OS and OR states would be in contention while states IR and OS would not This model is useful for open collector circuitry Different Contention occurs when a targeted net is driven by two or more pins that have opposite logic values signal strengths never cause contention For example two drivers with 1S and OS states would be in contention The states 1R and 1S would not be in contention NOTE Because an X state represents either a or a 0 it satisfies all contention conditions if it is one driver of any multiple driver net When checking for contention the simulator always ignores signals that have Z strengths d Enter a
173. ntax see Standard Delay Format Specification Version 2 1 Feb 1994 Correlating Signal Names Signal names parsed in the SDF file must match those found in the Technology File source Matching is case insensitive Wide buses are flattened and considered in a bitwise method It is not necessary to bundle buses in exactly the same way to match the individual bit Omitting the signal name in an SDF DEVICE statement is allowed and annotates all output pins of the instance as per the SDF specification Special Case Internal states and the THRU clause Timing arcs to internal states that are defined in the Technology File of an instance can be annotated using IOPATH if the path has a corresponding Technology File DELAY tP statement Timing arcs to or from internal states that are automatically generated by from other statements based on THRU directives may NOT be annotated directly Rather annotation should be directed to the original Technology File statements from which these arcs were generated This triggers the proper adjustment in the QuickSim II User s Manual V8 5_1 D 9 SDF Technology File Correlation SDF in QuickSim Il auto generated arcs For example a Technology File with the following statements tP egl ON inl THRU int_st TO out tP eq2 ON inl TO int_st will cause a third arc represented below to be generated internally in the timing model to complete the actual signal path through the devi
174. odels o Hardware physical models 1 2 QuickSim II User s Manual V8 5_1 Overview of QuickSim Il Why Simulate o Behavioral models written in a standard high level language o Technology description models Multiple states logic 1 0 and X unknown and multiple strengths strong resistive high impedance and indeterminate e Timing modes such as minimum typical and maximum timing values e Timing error checking such as setup and hold e Initialization and oscillation handling algorithms e Tri state and bidirectional modeling algorithms Why Simulate Computer simulation of digital circuits has long been used to extend the range of many types of analyses and to enable the analysis of larger and more complex designs This type of analysis when performed prior to the prototype stage ensures the design s quality earlier in the engineering process where errors are easier and cheaper to fix With a simulator you can analyze the design as you would on the test bench with stimulus probes and waveform displays The major benefit of the workstation is integration of this analysis task with other phases of the development cycle from concept to design to analysis to physical layout to the manufacturing test environment With this improved productivity design cycles can be considerably shorter than with the classic methods of paper pencil breadboard hand layout and manual test program generation QuickSim Il Over
175. on Here are some situations in which you may find saving the simulation state useful You want to end the current session and then later start from the point at which you ended Saving the simulation state is different than saving the results of the simulation which you do by saving the Results WDB You want to experiment with applying different sets of stimulus and need to repeatedly return to the same point in a simulation Your initialization requirements are lengthy and complex and you frequently reset simulation time to zero To save a simulation state perform the following steps 1 3 68 Choose the following pulldown menu path Menu Bar gt File gt Save gt State The simulator displays the Save State dialog box which is shown in Figure 3 27 QuickSim II User s Manual V8 5_1 Operating Procedures Saving and Restoring Simulation States Save State O Viewpoint Pathname quicksim_state Navigator _ Replace al Query when Waveform DBs have edits pending OK Reset Cancel Help Figure 3 27 Save State Dialog Box 2 Specify a location by using one of the following methods o Enter a pathname in the Pathname entry box The default for this pathname is the current working directory with the leafname of quicksim_state o Click on the Navigator button and use the dialog navigator o Click on the Viewpoint button If you click on the Viewpoint button the directory is that of th
176. on Y and schedules a transition to X immediately and then a transition to the final state 1 at time 8 nsec Spikes During Circuit Initialization To avoid spikes while the circuit is being initialized which is common in most models a power up grace period on these warnings can be specified with the Change Warning Start command Note that spike models will still be applied spike conditions will still affect the output pin but the warning messages for these spikes will not be generated and reported Spike Message Reporting You can specify whether or not messages are reported when spikes occur You can specify reporting for the entire design using the Quicksim shell command switch or on a hierarchical basis using the Change Spike Warnings command In addition new in release A 3 you can selectively suppress messages based on the 2 36 QuickSim II User s Manual V8 5_1 Key Concepts Waveform Databases action taken when a spike occurs This allows avoiding warnings when a spike is transported through the device intact but still warn about potential glitches when the spike falls in the X region Three switches are added to the Change Spike Warnings command to facilitate suppressing specific unwanted messages These are Suppress X and Transport The three switches can be used in any combination but are mutually exclusive with the on and off switches For more information on the Change Spike Warnings command refer to
177. on the Visible button QuickSim II User s Manual V8 5_ 1 Operating Procedures Invoking QuickSim Il QuickSim II Design Navigator Symbol Interface Timing mode Previous Unit Delay Constraint Detail of Delay timing mode Hidden Visible Timing mode Min Typ Max Unit Use Full Linear Delays Delay Scale 1 Constraint mode Off State only Messages Spike model X immediate Suppress _ Hazard check Spike warnings to display _ Contention check _ Suppress Bix _ Model messages _ Transport _ Toggle check Simulator resolution 0 1 ns _ Transport _ Blmcheck _ Bim debug OK Reset Cancel Figure 3 2 QuickSim Il Dialog Box d Fill out the dialog box the only required entry is the Design pathname Each entry or specification in the dialog box corresponds to a shell command line argument or switch The only required argument is the Design pathname argument For specific information about the command line arguments and switches refer to quicksim in the Digital Simulators Reference Manual e Click on the OK button at the bottom of the dialog box QuickSim II User s Manual V8 5_ 1 3 9 Invoking QuickSim Il Operating Procedures The Design Manager creates a new shell for the QuickSim II application a Conditions and modes that you set in the QuickSim II dialog box affect the root of the design and all levels below it Setting Note conditions and modes when
178. onic designs For general information especially about models and model types refer to Electronic Designs on page 2 2 For a more complete description refer to Digital Model Organization and Evaluation in the Digital Modeling Guide Effects of Design Changes After you make a design change during a simulation the simulator must make some adjustments The simulator handles design changes differently depending on whether or not the change affects the design connectivity Design connectivity refers to the way the nets pins and instances are connected or related and is always determined in the context of the design viewpoint Common to all changes The following behavior applies regardless of the type of design change The timing values are recalculated if necessary If timing values are being used the simulator recalculates them If the simulator is set up for unit delay simulation new timing values are not recalculated e All displayed timing information is invalidated The simulator lines out windows that contain invalid information such as the Timing Info windows Lining out consists of drawing diagonal lines with the window QuickSim II User s Manual V8 5_1 2 43 Design Changes in QuickSim Il Key Concepts borders The affected windows have update buttons small upward pointing arrows located near the window s minimize and maximize buttons that you can click on to update their contents e The stimulus and t
179. orm databases Contain compiled waveform data generated from the simulation or through stimulus input QuickSim II User s Manual V8 5_1 2 5 Design Evaluation and Model Selection Key Concepts A version freezing mechanism called latching allows you to maintain a specific version of your design and all the objects it references Design latching allows you to stabilize the version of your design so you can simulate it without dealing with incremental changes until you are ready When you are ready to test the updated version of the design you can unlatch the old version Then the next time you invoke the simulator it brings in the newest version of each object that the design references To maintain the new version you must again latch the design For detailed information about design viewpoints configurations and design latching refer to the Design Viewpoint Editor User s and Reference Manual Design Evaluation and Model Selection As the simulator invokes it evaluates the design and selects the functional and timing models to simulate The following information controls how the simulator evaluates the design and selects the simulation models Model registration labeling and Model property values When the simulator locates a primitive instance it matches the instance s Model property to the component s registered labels and then selects the models that the matching labels reference For background information about labels an
180. ory pathname in the Component Model Directory entry box and the name of the model in the Model_name entry box For example if you are simulating a design that contains a sheet based component that resides at my_path my_component you would specify the fields shown in Figure 3 34 QuickSim II User s Manual V8 5_1 3 79 Changing the Design in QuickSim Il Operating Procedures Reload Model Component Model Directory MY_PATH my component Model_name schematic Model Type N View Model Figure 3 34 Specifying a Model o Click on the View Model button and select the desired model in the resulting list box 3 Specify the type of model to reload by clicking on the appropriate Model Type button 4 Click on the OK button Remember that the simulator reloads the specified model for all instances that reference it For more information about reloading models see Reloading Models on page 2 46 For information about the Reload Model command refer to Design Viewpoint Editor User s and Reference Manual Writing Property Changes to a Specific Back Annotation Object You can save property changes to any back annotation object that the design viewpoint references To specify the back annotation object that is to receive all subsequent property additions and modifications perform the following steps 1 Create a design viewpoint window by choosing the following pulldown menu Menu Bar gt
181. ose either the Selected instances button or the Named instances button from the top of the dialog box If you choose the Named instances button you must also complete the Instance name entry box b Click on the Change button which reveals a new dialog box where you can click on the appropriate Timing mode button For information about the timing modes refer to Simulation Timing Modes on page 2 19 c To scale the delay values of the selected or specified instances enter a number in the Delay Scale entry box the default is 1 The simulator multiplies the delay values by the value you specify d To override the timing modes set at levels below the selected or specified instances click on the Override button Note that this button will not override lower level timing modes that were also set with the Override button QuickSim II User s Manual V8 5_1 3 35 Loading an SDF File Operating Procedures 4 Activate your choices by clicking the OK button at the bottom of the dialog box Loading an SDF File To meet these timing goals you are allowed to annotate the QuickSim II timing cache directly Once QuickSim II is invoked in min typ or max timing mode a timing cache exists that can be annotated with SDF file information The following procedure describes how to enable constraint checking for one or more instances 1 Choose the following pulldown menu path Menu Bar gt File gt Load gt SDF File The simula
182. p Getting Quick Help Getting Reference Help Entering and Exiting a Simulation QuickSim II User s Manual V8 5_ 1 Entering a Simulation Pre exit Considerations Common Simulation Interface Procedures Operating Procedures Cross Index Table 4 1 Operating Procedures in the SimView Common Simulation User s Manual Entering and Exiting a Simulation cont Exiting a Simulation Setting Up for Simulation Setting Up the Session Setting Up SimView Changing the SimView Environment Defaults Changing Window Display Formatting Defaults Setting Up the Kernel SimView Automating the Setup Procedures Saving Setups Restoring Setups Resetting Setups Manipulating Stimulus Creating Stimulus Modifying Stimulus Saving Stimulus Loading Waveform Databases into Program Memory Unloading a Waveform Database Connecting Stimulus to a Design Disconnecting Stimulus From a Design Controlling Simulation Running a Simulation Stopping a Simulation Resetting a Simulation Analyzing Simulation Results 4 2 Viewing Different Forms of Results QuickSim II User s Manual V8 5_ 1 Operating Procedures Ciissidnd ewing and Analysis Support DVAS Procedures Table 4 1 Operating Procedures in the SimView Common Simulation User s Manual Using Various Analysis Features Acting On the Simulation Data Changing
183. pe a count of the instances with Technology files e for each model type a count of the instances with constraint checking enabled the pathname to each non builtin model and their instance count the number of unique nets in the design reported as type NET This information is reported to the Info Messages report window The following procedure describes how to create a Model Statistics report 1 Select the desired hierarchical instances If you don t select anything Model Statistics for the entire design will be reported 2 Choose the following pulldown menu path Menu Bar gt Report gt Model Statistics The simulator displays the Report Model Statistics dialog box which is shown in Figure 3 22 Report Model Statistics Instance Note 7 report statistics for entire deisgn Figure 3 21 Report Model Statistics Dialog Box 3 Enter the instance hierarchical pathname or leave as is to report for the entire design QuickSim II User s Manual V8 5_1 3 53 Gathering Toggle Statistics Operating Procedures 4 Click the OK button The Info Message window appears with the model information you requested The following figure shows how this information is presented Statistics for instance T I 245 Instance Count By Model Type kxkkkKKKKKMOde L Statistics Information x COUNT total instances of specified mo
184. ped once to the pins of a model and the set of statements in the corresponding Technology File The mapping information is then stored in a template for the CELLTYPE of the cell being parsed Since SDF does not require that model wide templates be defined the set of SDF in templates will constantly be checked and modified if necessary Correlating an SDF Statement with a Technology File Statement The SDF parser drives the translation of the SDF file For each CELL the INSTANCE context is set then DELAY and TIMINGCHECK statements are processed Mapping of an SDF statement to a Technology File statement is a methodical attempt to find the best fit for each SDF statement Each statement is checked in each of the following categories D 8 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation e Signal names e Statement type e Signal edge transitions Conditional expressions SDF COND and Technology File WITH clauses If an SDF statement does not find a proper match in the Technology File a warning is given following its first encounter unless these warning messages are suppressed The rules for correlating the statement attributes are outlined in the following sub sections To understand this section readers should have a working knowledge of the MGC Technology File language and SDF syntax For Technology File syntax see the MGC Technology File Development Manual For the complete SDF sy
185. perating Procedures Checking Device Stability The simulator displays the Change Stability Check dialog box which is shown in Figure 3 24 with no design objects selected Change Stability Check On Selected objects Named objects Object name Stability check A ott wv On OK Reset Cancel Help Figure 3 24 Change Stability Check Dialog Box 3 Make the appropriate choices from the dialog box as follows a Choose either the Selected objects button or the Named objects button from the top of the dialog box If you choose the Named objects button you must also complete the Object name entry box b To enable stability checking click the On button c To specify a state that triggers the stability check click on the appropriate State button which are defined as follows e Any Triggers stability checking when the targeted signal makes any kind of logic transition Default QuickSim II User s Manual V8 5_ 1 3 59 Keeping Circuit Activity Operating Procedures e Triggers stability checking when the targeted signal transitions to 0 from either X or 1 o 1 Triggers stability checking when the targeted signal transitions to 1 from either X or 0 e X Triggers stability checking when the targeted signal transitions to X from either 0 or 1 d To override stability checking set at levels below the selected or specified objects click on the Override button Note that this button will
186. points to the section of text that describes the corresponding setup condition or command If you are viewing this manual online you can travel the hyperlink by positioning the pointer on the desired button or label and clicking the Select mouse button QuickSim II User s Manual V8 5_1 3 21 Setting Up QuickSim Il Operating Procedures 3 22 Setup Analysis Timing mode Current Unit Delay Constraint Detail of Delay timing mode Hidden Visible Timing mode typ Change Delay Scale 1 C Override Constraint mode Off State only Messages _ Override Spike model X immediate Suppress _ Override _ Hazard check _ Override Spike warnings to display _ Contention check _ Override __ Suppress _ Override Ej Model messages _ Override Bl X _ Transport __ Toggle check _ Override OK Reset Cancel Figure 3 5 Expanded Setup Analysis Dialog Box The items in the expanded portion of this dialog box establish setup conditions that propagate to lower levels in the design The Override buttons that appear to the right of these items allow you to override similar settings at lower levels If an item is set with the Override button at a lower level in the design the propagating effect of a setting at a higher level is ended For more information about this hierarchical behavior refer to Effects of Hierarchical Commands in the Digital Simulators Reference Manual To establish a spec
187. ported into AMP timing models This SDF information has become an industry standard maintained by Open Verilog International OVI SDF timing information exists in a file that can be imported into the timing cache that QuickSim II uses You can use two methods to import the SDF file Load SDF File command in QuickSim II This method allows you to directly annotate the timing cache from within QuickSim II For more information on the Load SDF File command refer to Load SDF File in the Digital Simulators Reference Manual e The importsdf switch to the Timebase command This option works within TimeBase to allow you to annotate and view SDF timing information interactively For more information on the use of the importsdf switch used with the timebase command refer to Importing an SDF File in TimeBase in the Technology File Development Manual OVI SDF Versions Supported The initial release of SDF in will support OVI version 2 1 of SDF with two exceptions PATHPULSE and GLOBALPATHPULSE annotation will not be supported in this release Also annotation of net delays are supported using the INTERCONNECT statement but the more global NETDELAY statement which has been dropped in SDF V3 0 will not be supported OVI SDF Version 2 0 syntax is a subset of V2 1 and will also be supported QuickSim II User s Manual V8 5_1 D 1 The Annotation Process SDF in QuickSim Il OVI SDF Version 1 0 syntax is conditionally supported Vers
188. rather than a result of running out of memory Memory Fault problems may be related to Out of Memory problems although they are less common Memory Fault errors are typically caused by the following 1 Logic Modeling s LMC_QSIM utilities bind_utilities needs to be run Installing new software can cause the link pointing to the Logic Modeling software to be replaced Re running bind_utilities recreates the link 2 Network problems have on rare occasion caused QuickSim failures with the Memory Fault message 3 If you are using Logic Modeling s R38 or later SmartModel library it is possible to receive a Memory Fault if your environment is not set up properly for the SmartModel license The LM_LICENSE_FILE environment variable must point to the location of your LMC_QSIM auth adm smartlicense dat file For more information see your SmartModel documentation and release notes A 16 QuickSim II User s Manual V8 5_1 QuickSim Il Troubleshooting Error Messages Issued Error Messages Issued There are a large number of possible error messages that you can encounter when invoking QuickSim Some of these messages are generated by QuickSim or TimeBase while others may be generated by the ASIC vendor s library that has been used in your design Cannot Connect to Child Cannot connect to child Too Many Net Recursions Too many net recursions e Parameter Undefined TSUD Parameter undefined TSUD QuickSim II User s
189. rea Backtrace complete There are no more nets in this path that have an X state value You can now examine the instance that is attached to the selected nets to see why it is generating the X state Changing the Design in QuickSim Il During a simulation session you can change your design without exiting and re invoking the simulator The design changes you can perform during a simulation include reloading models swapping models and changing property values For a discussion of the effects of these categories of design changes refer to Design Changes in QuickSim I which begins on page 2 42 Reloading A Model To reload a specific model perform the following steps 1 Choose the following pulldown menu path Menu Bar gt File gt Load gt New Models gt Specified The simulator displays the Reload Model dialog box which is shown in Figure 3 33 3 78 QuickSim II User s Manual V8 5_1 Operating Procedures Changing the Design in QuickSim Il Reload Model Component Model Directory View Model Model_ name a Model Type A Schematic HDL Arch HDL Entity All instances in the entire Quick Part design that reference this Quick Part Table model will be reloaded TechFile Lib TechFile Memory Table Model OK Reset Cancel Vv Vv Vv Vv Vv Vv VY Figure 3 33 Reload Model Dialog Box 2 Specify a model by using one of the following methods o Enter the model s direct
190. reate aR 2 Design Viewpoint sabe y ee SPENE D Optionally Run Analyze Results TimeBaseto A Calculate Timing E Modify Design Bie een ae E optional Figure 1 2 QuickSim II Design Flow The generic design flow is as follows 1 Select and obtain the models you need to create your design based on the specified requirements If your design is an ASIC you typically choose a set of models from an ASIC library vendor ASIC vendor libraries contain predefined circuit configurations that are integrated into their specific manufacturing environment and can provide a high level of accuracy 2 Capture the design You can capture designs using the Design Architect which supports traditional schematic based design System 1076 VHDL modeling and the five AutoLogic Input Formats You can use the AutoLogic synthesis application to synthesize VHDL models into either QuickSim II User s Manual V8 5_1 1 7 QuickSim II Overview Overview of QuickSim Il 1 8 netlists or gate representations both of which are compatible in the simulator For information about synthesizing VHDL models refer to the AutoLogic VHDL Synthesis Guide For information about the AutoLogic Input Formats refer to the AutoLogic BLOCKS Manual Optionally invoke the Design Viewpoint Editor DVE to create a viewpoint that defines a custom configuration For more information about design viewpoints refer to Design Viewpo
191. revails over posedge as well as NONE for Rising Technology File edges IOPATH 01 clk q 19 11 23 17 23 11 QuickSim II User s Manual V8 5_1 D 17 SDF Technology File Correlation SDF in QuickSim Il Finally an SDF statement similar to the one above but with the matching COND condition would be considered an even better fit for the top statement COND clr IOPATH 01 clk q 20 11 23 17 23 11 Correlating Output Pin Transitions For TIMINGCHECK SDF statements the to pin transition is fitted the same way as on pins inputs as discussed above But for SDF path delays IOPATH no output pin transition is specified since data for all possible transitions can appear in the SDF data field The to pin output transition in the Technology File is not considered when correlating an SDF IOPATH statement to a Technology File DELAY edge Rather the Technology File transition is used to indicate where SDF in will look for data in the SDF data field Twelve Value Data Fields The V2 1 SDF data field can have up to 12 data sets rvalues which may be values or triplets to indicate the possible transitions of a 4 state model Table D 3 below shows with an X where the Technology File s to pin transitions specify to look for data in a 12 value SDF data field When multiple columns are marked SDF in will use the largest delay value found among them for the timing mode being
192. riorities When the simulator invokes it reads multiple back annotation objects according to the priority beginning with the lowest and ending with the highest If the same property is changed in more than one back annotation object the change specified in the higher priority back annotation object supersedes the others By default the simulator writes to the back annotation object that has the highest priority but you can specify that the changes be written to any of the referenced back annotation objects To write a property change to a specific back annotation object you need to first display a list of the back annotation objects that the design viewpoint references which you can do by choosing the Menu Bar gt Report gt Design Viewpoint pulldown menu path Then before you change the property click on the back annotation object that you want to receive the property change The simulator writes all subsequent property changes to the selected back annotation object however its priority remains unchanged You cannot change the priority of a back annotation object within the simulator but you can do so within the Design Viewpoint Editor DVE For information about managing multiple back annotations and back annotations in general refer to the Design Viewpoint Editor User s and Reference Manual Loading Net Delays into QuickSim II QuickSim II allows you to load Netdelay information from external files in particular IDD type which
193. ronic design The simulator reads stimulus from and writes results to waveform databases A waveform database is a compiled form of the design s activity During the simulation session you can modify the design You can change property values to correct design errors or to perform what if analysis You can also update technology files VHDL source files schematics and compiled models such as QuickPart Tables and QuickPart Schematics A back annotation object stores the edits made to the associated design during the simulation session For more information about modifying your design during a simulation refer to page 3 78 e The SimView simulator creates waveform databases and allows you to analyze simulation data that QuickSim II creates SimView is sometimes called a read only simulator because it cannot calculate circuit behavior However SimView can create and save waveform databases as well as setup data such as breakpoints and simulation expressions For more information about SimView refer to the SimView Common Simulation User s Manual QuickSim II User s Manual V8 5_1 1 11 QuickSim II Overview Overview of QuickSim Il Simulator Architecture The simulator consists of several major pieces of software The pieces are organized into an architecture that optimizes simulation efficiency and performance Figure 1 4 shows a representation of the simulator architecture QuickSim Il Front En
194. roup Name cycles Table 3 2 System Setup Groups Description Cycle information for SimView assertions expressions User defined expressions hdl_setup Array size VHDL assert severity heir_modes Spike model timing mode inst timing scale constraint_mode kernel checking model_messages keeps List of signals whose activity is to be stored in temporary memory list_ windows Open List windows and their contained signals and attributes model_load Loads specified modelfiles monitor_flags Monitor flags font wdb format monitor_windows Open Monitor windows and their contained signals and attributes probes Probes synonyms and flags qs_parameters Kernel time scale absfile check_blm inertial transport delay run_setup Iteration limit keep time keep type full window template run run type quiet until stop step session_attributes Palettes softkeys menu bar title area Message area window layout simview_attributes Force template clock period pin coercion 4 9 12 state mapping source_views Open source views sheets QuickSim II User s Manual V8 5_ 1 Operating Procedures Restoring Setup Conditions Table 3 2 System Setup Groups Group Name Description synonyms Instance synonym definitions trace_windows Open Trace windows and their contained signals cursors and attr
195. s e Window Report Files Contain ASCII representations of text based windows such as the List Breakpoints Waveforms and Transcript windows e Waveform Database Contains waveform data that was stored in memory In memory waveform databases include the Results Stimulus and Forces waveform databases all three are created and maintained by the simulator and any waveform database that you have previously loaded into memory Logfile Contains simulation results in ASCII format You can create logfiles from the contents of any loaded in memory waveform database Logfile contents and syntax is described in Simulation Logfiles in the SimView Common Simulation Reference Manual Force File Contains Force commands The simulator can create a force file from the waveforms in waveform databases such as either the Forces or the Stimulus waveform database e Setup Objects Contain information about the simulator s initial setup conditions You can save these in the design viewpoint container to maintain a strong association to your simulation e Save State Objects Contain information about the simulator s state You can save these in the design viewpoint container to maintain a strong association to your simulation e RAM ROM Files Contain the current contents of a RAM or ROM in the design These ASCII files are produced by the Write Modelfile command and are represented in modelfile format QuickSim II User s Manual V8 5
196. s Manual V8 5_ 1 Key Concepts Spike Models Current Time scheduled new time current time current X state final Xstate tinal 4 Duration of X state with suppress spike model Duration of X state with X immediate spike model Figure 2 9 X Duration for Spikes with Two tPX Transitions e If the scheduled state is not a tPX transition and it is the same as the X portion of the new state s tPX transition the duration of the X portion begins with the earliest X state and lasts until the latest final state This produces a worst case handling of the spike Figure 2 10 shows two waveforms and identifies the duration of the resulting X state If the scheduled state is not the same as the X portion of the new state s tPX transition the simulator simply removes the scheduled state from the event queue and schedules the new tPX transition without adjusting the duration of the X state Time _ Current scheduled new current state et state current X state State uration of X state wit uppress spike mode Duration of X state with X immediate spike model Figure 2 10 X Duration for Spikes with One tPX Transition QuickSim II User s Manual V8 5_ 1 2 27 Spike Models Key Concepts To receive notification of spike conditions you can use th
197. s when the breakpoint interrupts the simulation enter the functions in the Action list entry box The functions must conform to all AMPLE syntax requirements 3 If you want to interrupt the simulation based on an activated VHDL object perform the following steps a Click on the Object button The simulator expands the dialog box The expanded portion of the Add Breakpoint dialog box is shown in Figure 3 30 QuickSim II User s Manual V8 5_1 3 73 Using Breakpoints Operating Procedures 3 74 Add Breakpoint On Expression VHDL object VHDL object Qualifier m On change On occurrence 1 Jm End of timestep Action list jm Stop simulation Ej Delay actions Jm Filter redundant events OK Reset Cancel Help Figure 3 30 VHDL Portion of Add Breakpoint Dialog Box b Enter a VHDL object in the Object entry box A VHDL object is the label or hierarchical name of a VHDL block process or executable statement The breakpoint condition is satisfied when the first executable statement associated with the specified VHDL object is activated Optionally enter a simulation expression in the Qualifier entry box For information about defining simulation expressions refer to Simulation Expressions in the SimView Common Simulation Reference Manual To specify that the breakpoint occurs when the evaluation of the Qualifier entry changes while the specified VHDL object is activated cli
198. simulation is described in the next section Running a Batch Simulation For simulation jobs that don t require visual feedback for interaction you can run QuickSim II as a batch simulator The advantage to running a batch simulation is an increase in simulation performance because a batch simulation runs without graphics To run the simulator in batch mode you must invoke it from an operating system shell instead of from the Design Manager The two approaches to batch mode simulation are as follows e Using redirected input e Using a here document Both approaches use the Nodisplay command line switch The following sections describe the methods of batch simulation Using Redirected Input One approach to batch simulation is to use redirected input Redirected input where you redirect a simulation dofile to the simulator directly on the command line The following procedure describes how to use redirected input for a batch simulation 1 Create a file called a dofile or a logical transcript that contains the commands and functions you want the simulator to execute during the simulation QuickSim II User s Manual V8 5_1 3 11 Running a Batch Simulation Operating Procedures A common way to collect the simulation commands and functions is as follows a Perform the simulation in interactive mode and save in a file the contents of the Transcript window b If desired edit the dofile to add or remove functions
199. ssociated delays This three step process 1s an iteration QuickSim II User s Manual V8 5_1 2 15 How QuickSim II Processes Circuit Activity Key Concepts If an resulting events have a delay of 0 the simulator schedules them in a new event list in the current slot Immediately these events become mature requiring the simulator to perform another iteration for the current slot The simulator repeatedly performs iterations until either there are no more events in the current slot or an iteration limit is reached You can limit iterations with the Set Iteration Limit command described in the Digital Simulators Reference Manual If the delay of an event is greater than the amount of time in one revolution of the wheel QuickSim II saves the event and schedules it later If this kind of delay happens frequently it can decrease the simulator s performance The Scheduling Algorithm When the simulator reads a design electrical connectivity is established with three fundamental elements pins instances and nets Instances represent the component s behavior and graphical representation nets connect instances together and pins are the interface between instances and nets Figure 2 5 shows a schematic based design On the schematic pins bold portions are labeled P1 through P6 instances are labeled I1 through I3 and nets are labeled A through D The numbers that appear below the pin labels indicate the associated delay
200. st_des it hangs never loading the design because the symbol test has a schematic that also contains the symbol test QuickSim II User s Manual V8 5_1 A 7 Quicksim II Hangs During Invocation QuickSim Il Troubleshooting NOTICE THAT THE CIB VIEW OF TEST DOESN T APPEAR ODD COMPONENT test DEFAULT INTERFACE IS test INTERFACE test PINS Compiled User Id Pin Name Pin Name Properties 1 PRE PRE pin PRE pintype ENA 2 CLR CLR pin CLR pintype ENA 3 Q Q pin Q pintype OUT 4 J J pin J pintype IN 5 CLK CLK pin CLK lt p gt pintype ENA 6 QB QB pin QB pintype OUT 7 K K pin K pintype IN BODY PROPERTIES model value qbfall 0 qbrise 0 qfall 0 qrise 0 NTERFACE MODEL ENTRIES Model Entry Type Model Info 0 mgc_symbol Path TIMP test Labels default_sym Status Valid for interface Valid for property 1 mgc_schematic Path TIMP schematic Labels schematic Sschematic default Status Valid for interface Valid for property QuickSim II User s Manual V8 5_ 1 QuickSim Il Troubleshooting Quicksim II Hangs During Invocation NOTICE THAT CIB VIEW OF TEST_DES DOES NOT APPEAR ODD COMPONENT test_des DEFAULT INTERFACE IS test_des INTERFACE test
201. stics for nets that toggled only to 1 and not to 0 e Zero Reports statistics for nets that toggled only to 0 and not to 1 None Reports statistics for nets that did not toggle to 1 or to 0 e Any Reports the nets that had toggle checking enabled c Choose a short or long report using one of the Detail amount buttons d To override the toggle reporting set at levels below the selected or specified objects click on the Override button Note that this button will not override lower level toggle reporting that was also set with the Override button 4 Activate your choices by clicking the OK button Checking Device Stability You can check for circuit activity when a specific signal changes state such as a clock signal which can be useful for analyzing synchronous designs or portions of designs For example you may want to know if a synchronous design is stable when the active edge of a clock signal transitions The following procedure describes how to control stability checking 1 Select the desired nets or buses You can verify that you have selected only the desired objects by looking at the highlighting in the displayed windows Although object selection is not required it is generally easier than specifying names of objects in the dialog box created in the next step 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Stability Check 3 58 QuickSim II User s Manual V8 5_1 O
202. t 2 10 QuickSim II User s Manual V8 5_1 Key Concepts Simulator Accuracy has a fixed signal state which is useful in debugging because it cancels the effects of any driving output that is connected to the net Simulator Accuracy The accuracy of a simulator can be measured in two ways accuracy in the verification of logical state strength values and accuracy in timing Logical Accuracy Logical accuracy is a direct function of the signal states that the simulator can model When more than one signal is connected to one net the simulator must have a means of determining an accurate result Table 2 3 see page 2 12 is a matrix that describes how the simulator resolves node contention between two or more output pins To determine the state of a node connected to the outputs of two gates the simulator figuratively locates the output state of one gate in the left hand column and the output state of the other gate in the top row their cross point indicates the state of the node When more than two outputs are connected the simulator first separates the signal states into two categories signals of strengths S R or Z and signals of strength I Then it calculates a single state for each category as follows it plots the result of two states from the same category and then plots that result with another state in the same category It continues combining plotted results with output states until it has a single state for each categor
203. t command allows you to set a grace period for which warning messages and violation actions are not performed This will allow your design to stabilize properly initial memory data to be retained and eliminate the clutter of inappropriate warning messages The Change Warning Start command is described in the Digital Simulators Reference Manual Design Changes in QuickSim Il QuickSim IT supports incremental design changes which can dramatically decrease the time for a design iteration the cycle of design creation revision and simulation depending on how much of the design is actually affected You can make three basic types of design changes without exiting the simulator Model reloading You can reload models to obtain the most recent model version For example assume that you invoke the simulator on a large design and after simulating for a while you discover a problem with the schematic or a technology file You can correct the problem using the appropriate editor recompile if necessary and reload the result into the simulation without having to exit and re invoke the simulator For more information about reloading models refer to Reloading Models on page 2 46 Model swapping You can swap models by substituting one model representation for another This swap is accomplished by changing the value of the Model property For example if you want to begin to use a gate representation in place of a VHDL you can change
204. tate Objects Contain information about the simulator s state You can restore a saved state to establish the same point in a simulation that was achieved in a previous session Environment Variables These are set in a command window or shell prior to invoking QuickSim II A list of environment variables used by QuickSim II is described in Appendix C Figure 1 6 shows the types of output data that QuickSim II can produce QuickSim II Display Window Waveform Set d Window Report Files ese SE E Plots Design Viewpoint Logfile Back The simulator s output can include the following kinds of data Objects RAM ROM Files Figure 1 6 QuickSim II Output Or Annotation Stimulus Objects e Display Shows you the simulation waveforms and logic state values To save time you can omit the display by using the Nodisplay switch when you invoke the simulator You might use the Nodisplay batch approach 1 16 QuickSim II User s Manual V8 5_1 Overview of QuickSim Il QuickSim II Overview when simulating a large design Instead of displaying the results immediately you can store them in either a waveform database or a logfile and view them later Design Viewpoint Defines the design configuration rules and holds design viewpoint related data such as the simulation timing cache waveform databases logfiles save state and setup objects and connections to back annotation object
205. tation tool set lt N Falcon Framework Schematic Digital Capture Simulation Design QuickSim Il Architect SimView Physical Test Layout QuickGrade Il Seton QuickFault Il Y Hardware Modeling LM Series QuickSim II User s Manual V8 5_1 Architectural Component Modeling Modeling BLMs QuickPart Schematic System 1076 QuickPart Table Memory Table Model Sheet Based Parts Figure 1 1 IDEA Tool Set 1 5 QuickSim II Overview Overview of QuickSim Il QuickSim IT operates on a model of a digital logic circuit which consists of parts that you have connected together using design creation applications such as Design Architect Before you create your design you need to obtain the parts that your design requires You can create your own parts using any of the component architectural or hardware modeling techniques that QuickSim II supports You can also use parts from libraries provided by third party vendors When your design simulates correctly you can perform the physical layout which is supported by other Mentor Graphics tool sets Or if you are using a third party library the library vendor might perform the layout Data that is calculated during design layout might include load dependent dela
206. ted across the device This means that both state changes from event and event2 will be scheduled on the output The output will change from stateO to state at time tl d1 and change from statel to state2 when event2 matures at time t2 d2 This behavior is shown in Figure 2 16 suppress limit 4 lt gt x_limit 7 gt d1 13 a gt IN event1 scheduled at time t1 d1 i event2 at time t2 d2 OUT a a 0 t t2 Figure 2 16 Pulse in Transport Region X_limit lt t2 t1 lt d1 Note When an event to be transported is scheduled the delay used is determined by the state transition from the previously scheduled event event1 and the new event event2 instead of from the transition between the current state state0 and the new event The assumption is that if a pulse is wide enough to be transported the scheduled state more closely matches the current internal state of the device than the output state Scheduling Events Before Other Scheduled Events When events are already scheduled on the output pin as a result of previous spikes that are being transported and a new event needs to be inserted into the queue of scheduled events for that output pin rather than appended to the end all events 2 34 QuickSim II User s Manual V8 5_1 Key Concepts Spike Models that are scheduled to occur after the latest entered event are discarded This concept is illustrated in Figure 2 17
207. terms and definitions Logic value 1 0 or X either 1 or 0 e Strength S strong R resistive I indeterminate Z high impedance e Driving signal Any signal that does not have a Z strength The contention model defines the circumstances that identify a contention condition When setting the contention model you can also specify an amount of time that the contention condition must exist before the simulator generates any warning message You can set the contention model for any bus net or at the design root and you can specify these items using selection or specific design names When you set the model on a bus or net the property affects only that bus or net When you set it on the design root it affects all the nets in the design 3 44 QuickSim II User s Manual V8 5_ 1 Operating Procedures Changing the Contention Model When the simulator detects a valid contention condition it creates a message window and displays a message that describes the reason for the contention You can set the contention model on any net bus or at the design root The following procedure describes how to set this model 1 Select the desired net or bus You can verify that you have selected only the desired instances by looking at the highlighting in the displayed windows Although instance selection is not required it is generally easier than specifying names of instances in the dialog box created in the next step 2
208. that will be tolerated before the load operation aborts 3 Activate your choices by clicking the OK button at the bottom of the dialog box The Load SDF operation begins writing load information to the Info Messages report window In addition the compilation time is reported Checking for Design Constraints Design constraints are device limitations that you define in technology files During the simulation the simulator can verify whether these constraints are being met if they are not it can respond with an appropriate warning message You can define design constraints for device limitations such as setup and hold requirements and frequency limitations QuickSim II User s Manual V8 5_1 3 37 Checking for Design Constraints Operating Procedures During a simulation session you can enable constraint checking for specific instances at any design level The following procedure describes how to enable constraint checking for one or more instances 1 Select the desired instance or instances You can verify that you have selected only the desired instances by looking at the highlighting in the displayed windows Although instance selection is not required it is generally easier than specifying instance names in the dialog box 2 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Constraint Mode The simulator displays the Change Constraint Mode dialog box which is shown in Figure
209. the Stimulus Changing Your Design Design Viewing and Analysis Support DVAS Procedures Table 4 2 Operating Procedures that are found in the Design Viewing and Analysis Support Manual Selecting Objects Selecting Objects Graphically Unselecting Objects Graphically Selecting Objects by Name Selecting Every Instance Net or Pin in a Design Selecting Objects by Property Unselecting Objects by Property Selecting Objects by System Property Selecting Based on Connectivity Examining Levels of the Design Opening a Sheet for the Selected Hierarchy Objects Opening a Sheet Implementing the Current Instances Removing a View Window Scaling the Contents of a View Viewing the Entire Sheet Window QuickSim II User s Manual V8 5_ 1 4 3 Design Viewing and Analysis Support DVAS P perdtings Procedures Cross Index Table 4 2 Operating Procedures that are found in the Design Viewing and Analysis Support Manual Enlarging a Portion of the Sheet Scaling the Contents of a View Zooming In and Out on a Sheet Window cont Scrolling the View Window Using Protection Preventing Objects From Being Selected Unprotecting Protected Objects Using the Selection Filter Using Groups Creating a Group of Items Selecting and Unselecting Groups Current Naming Context Setting the Naming Context Reporting the Naming Context The Effective Context
210. the models into an identifiable group The simulator selects the models that it uses during simulation according to how they are labeled The value of the instance s Model property determines the labels that the simulator selects For example you could have several technology models where each one has a different label and describes a different set of process requirements If the associated graphical model has all of these labels it could be grouped with any of the technology models for any given instance This ease of association provides flexibility For more information about how QuickSim II selects models refer to Design Evaluation and Model Selection on page 2 6 For more information about how to register and label models refer to DA Model Registration in the Design Architect User s Manual Design Viewpoints and QuickSim Il A design viewpoint is a data object that performs two functions it defines the set of configuration rules that the simulator uses to evaluate the design and it serves as a container object in which information related to the simulation can be managed A design configuration can define four categories of rules 2 4 QuickSim II User s Manual V8 5_1 Key Concepts Design Viewpoints and QuickSim Il Parameter The value of a design based variable that is resolved outside of the component For example you can use parameters to define bus widths so that the design can be configured appropriately for dif
211. the value of the Model property from within the simulator so that it refers to the schematic For general information about models and model types refer to Electronic Designs on page 2 2 For more information about swapping models refer to Swapping Models on page 2 47 Design property changes You can add or change property values directly in the simulator This activity is referred to as annotating the design For 2 42 QuickSim II User s Manual V8 5_1 Key Concepts Design Changes in QuickSim Il more information about changing design properties refer to Changing Properties on page 2 47 From within the simulator you can also import ASCII back annotation files which contain a set of property changes formatted in ASCII For information about importing ASCII back annotation files refer to Importing an ASCII Back Annotation File in the Design Viewpoint Editor User s and Reference Manual The simulator keeps track of all incremental design changes This tracking ensures compatibility with related design information that is saved such as the timing cache and save state data objects The simulator automatically checks the data objects that are dependent on the design configuration and prohibits them from being used if they are not compatible To understand the capabilities and the effects of changing your design in QuickSim II you need to fully understand the concept structure and constituents of electr
212. to Technology File statements For more information on the sim_ cmp system function refer to sim_ cmp in the Technology File Development Manual Unsupported operators Some operators that are legal in SDF do not correlate with AMP WITH expressions and are ignored The following operators are ignored in this version of SDF in QuickSim II User s Manual V8 5_1 D 13 SDF Technology File Correlation SDF in QuickSim Il e Unary operators amp amp l e Binary operators lt lt gt gt gt gt lt lt The conditional operation lt test gt lt expr gt lt expr gt e List concatenation using a comma Correlating Input Pin Transitions SDF allows the specification of an input transition by using one of eight edge specifiers posedge negedge 01 10 OZ Z1 1Z ZO For example see posedge in the delay statement below COND clr IOPATH posedge clk q 17 11 23 17 23 11 Technology Files may specify almost any paired combination of the states A L H V X T U For a definition of these see the Technology File Development Manual In order to correlate the 70 possible Technology File edge transitions to the 8 used in SDF we first put them into more general categories as below e Rising Is defined as LH VH LV e Falling Is defined as HL VL HV Not Falling Includes these transitions LX LA LT LU XH AH TH UH RI and the state H
213. tor displays the Change Constraint Mode dialog box which is shown in Figure 3 14 Load SDF File Pathname Navigator Instance Relative context for SDF Design path Message reporting mode Context Syntax Verbose Max Errors Number of errors before loading aborts OK Reset Cancel Help Figure 3 13 Change Constraint Mode Dialog Box 2 Make the appropriate choices from the dialog box as follows a Enter the pathname to the SDF file or use the Navigator button to find and select the SDF file 3 36 QuickSim II User s Manual V8 5_1 Operating Procedures Checking for Design Constraints b If you only want to annotate part of your design such as an ASIC instance enter the instance path For example i 231 c Click on the message reporting mode button that best fits your needs The detail of information that is presented follows o Context Default Will output warnings when SDF in is unable to find an instance or instance is of the wrong type ex non primitive to receives SDF data This is the default mode Syntax error are also reported in this mode o Syntax In this mode only syntax errors found while parsing the SDF file are reported o Verbose Used by modelers to output a report of the correlation between the SDF in template and the Technology File as well as other informational messages Context and syntax errors will also be reported d Optionally enter the MaxErrors
214. ts built in primitives QuickPart Tables QuickPart Schematics Memory Table Models System 1076 VHDL models Hardware Modeling Library HML and LM Family hardware models and Behavioral Language Models BLMs For general information about modeling capabilities and techniques refer to the Digital Modeling Guide Technology Files Provide pin to pin path delay pin rise and fall delays timing constraints custom error condition messages and technology 1 14 QuickSim II User s Manual V8 5_1 Overview of QuickSim Il QuickSim II Overview dependent data You create and compile technology files as part of the modeling process Notice that compiled technology files are considered models because they add to the overall definition of a component For more information about technology files refer to the Technology File Development Manual e Standard Delay File format SDF Can be directly annotated into the timing cache object used by QuickSim II so that SDF timing delays can be used directly in a simulation QuickSim II and TimeBase can annotate this information e Linear Technology Files Provide straight line approximations of the timing that is defined by a technology file When you use linear technology files a typical design s timing is computed approximately 10 times faster than when you use full technology files For more information about linear technology files refer to the Technology File Development Manual e Waveform D
215. type of initialization in the simulator using the Initialize command with the Classic switch Note that the classic style of initialization cannot be used when you simulate a design that consists of or contains System 1076 models 1 QuickSim II sets all nets according to associated Init properties 2 It sets all other nets to XR or to the state specified with the Initialize command 3 Using a delay of 0 for every transition the simulator propagates the initialized values through the circuit until it reaches a stable state no zero delay events or until the simulator reaches the iteration limit The simulator does not advance simulation time during classic initialization Suppressing Warnings During Initialization The initialization that QuickSim II performs at invocation does not advance the simulation clock In addition default initialization does not stabilize the design You may want to continue this initialization with a short initialization run to stabilize your design before gathering simulation data Some of the dynamic checks done during simulation are unwarranted during your circuit initialization run Memory Table models of RAMs with initialized memory may invalidate when unknown signals X are on address and control lines QuickSim II User s Manual V8 5_1 2 41 Design Changes in QuickSim Il Key Concepts Spikes hazards net contention and setup hold violations are common at this time The Change Warning Star
216. ure 3 5 Figure 3 6 Figure 3 7 Figure 3 8 Figure 3 9 Figure 3 10 XV IDEA Tool Set 1 5 QuickSim IT Design Flow 1 7 QuickSim IT Data Flow 1 10 Architecture of QuickSim I 1 12 QuickSim II Input 1 14 QuickSim IT Output 1 16 An Electronic Design 2 2 Model Selection Flow Chart 2 7 Simple Events 2 14 Timing Wheel 2 15 How the Simulator Sees the Schematic 2 16 Scheduling Events 2 18 Timing Mode Comparison 2 19 Inertial and Transport Delay Modes 2 22 X Duration for Spikes with Two tPX Transitions 2 27 X Duration for Spikes with One tPX Transition 2 27 Spike Pulse Propagation Regions 2 28 Single Output Device Spike Example 2 30 Pulse in Suppress Region t2 tl lt suppress limit_____ 3 1 X pulse Region suppress_limit lt t2 tl lt x_limit__________2 33 Pulse in X pulse Region X immediate is Specified 2 33 Pulse in Transport Region X_limit lt t2 t lt dJ ___ S S CSC 34 Spike with Previous Event Scheduled____PJ ___ Scheduling Multiple Spike Models 2 36 Design Manager Session Window 3 7 QuickSim ITI Dialog Box 3 9 Exit QuickSim Dialog Box 3 14 Setup Analysis Dialog Box 3 20 Expanded Setup Analysis Dialog Box 3 22 Change Timing Mode Dialog Box 3 24 INIT Prompt Bar 3 25 Change Warning Start Dialog Box 3 26 Change Warning Start User Specifications 3 26 Save Setup Dialog Box 3 28 QuickSim II User s Manual V8 5_1 Table of Contents Figure 3 11 Figure 3 12 Figure 3 13 Figure 3 14 Fi
217. us two and take 11 from the 10 second column Six Value Data Fields Pre V2 1 SDF formats are limited to 6 or fewer rvalues This format does not allow for explicit annotation of specific transition to or from X Technology File transitions that would look for data in the X rvalues the last six columns of the table above in the twelve state format are redirected as shown in Figure D 2 i Ol 10 OZ Zl 1Z ZO OX X1 1X XO XZ ZX b bo Ay Figure D 2 Twelve to Six Rvalue Transform Three Value Data Fields It is also legal to specify only three rvalues in SDF for AH AL and AZ transitions If only three data fields are parsed and the 12 field format specifies to look for data only in columns 4 12 then the twelve to six transform above is performed If that mapping does not specify a data location in the first three fields the six to three transform below is performed D 22 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation y yp Pp 01 10 0Z Z1 1z ZO Figure D 3 Six to Three Rvalue Transform For example if a Technology File statement tP 12 ON clk AA TO q ZU is encountered and only three data fields appear as in the SDF statement IOPATH CLK Q 1 2 3 then the SDF ZX field where data would be found in a 12 field format is mapped to Z1 and ZO according to Figure D 2 which is then mapped to 10 and 01 according to Figure D 3 The
218. used For example given the following SDF delay statement TOPATH clk 1 2 3 4 9 6 7 8 9 10 11 12 This Technology File statement tP 11 ON clk LH TO q AA is given the longest delay from the SDF data which is 12 While this Technology File statement tP 11 ON clk LH TO q AH looks in the 01 Z1 and X1 locations second table row and chooses 8 D 18 QuickSim II User s Manual V8 5_1 SDF in QuickSim Il SDF Technology File Correlation Table D 3 Technology File to SDF 12 Value Data Field TRANS 01 oZ Z1 1Z OX X1 1X XZ ZX AA X X X X X X AH AL AT AU AV AX AZ MIPS PS IP IP lt MIPS PS IP IP lt MIPS PS iP IP lt FA PSPS PSPS ies S P lt IPS PIP PX eK S HA JSI I lt HL HT HU gt lt HV HX PPS PS IPS PSPS P a Ps SS HZ LA LH LT LU LV LX LZ RI TA I lt P lt IP TH TL TT TU TV TX MIP PS PA IP IPS IPS IPS IPS I lt lt lt PS IPS lt lt PS PS IP P lt lt PS IPS lt TZ UA UH lt lt UL QuickSim II User s Manual V8 5_ 1 D 19 SDF Technology File Correlation SDF in QuickSim Il Table D 3 Technology File to SDF 12 Value Data Field TRAN
219. view The QuickSim II logic simulator is a sophisticated computer program that allows you to test a software breadboard of a digital hardware design It is an interactive logic simulator that allows you to verify the functionality of models of electronic designs QuickSim I has the following features QuickSim II User s Manual V8 5_ 1 1 3 QuickSim Il Overview Overview of QuickSim Il 12 state ttming wheel simulator that can simulate technologies such as CMOS TTL ECL and so on Logic analyzer type tracing that lets you graphically examine the logic states of signals e Interactive control of the simulation that lets you control and observe the state of any signal in the design You can trace list monitor stimulate or set breakpoints on any signal e An interface that is shared with other Mentor Graphics simulators and is compliant with Motif standards to provide a common look and feel This visual interface is called SimView UI e The ability to save setup conditions stimulus and particular states of the simulation so that they can be restored at any time in the future Incremental design capabilities that let you update modified design components and change property values during the simulation even if the change affects the design s connectivity or timing These incremental design capabilities let you make a change and then resume the simulation quickly e The ability to perform simulations with varying
220. vity The basic unit of time resolution for QuickSim II is the timestep which is user set and which defaults to 0 1nS when the simulator is invoked QuickSim II uses timestep increments to model the passing of time during a simulation run All simulation activity occurs within timestep boundaries The smaller the timestep the greater the timing resolution Modeling attributes help describe some of the real world timing characteristics of components You typically develop modeling attributes during the schematic entry phase of the design process Examples of the modeling attributes include the following Minimum typical and maximum timing for rising and falling signals on inputs and outputs inertial delay Minimum typical and maximum pin to pin timing which is defined in technology files Setup hold skew and minimum pulse width timing checks and clock frequency constraints Timing constraint violations that affect output pin states Timing as a function of pin loading and simulated physical effects Transport delays for HML LM Family models and QuickPart Schematics but not for QuickPart Tables Compensation routines annotate the timing of a design with load dependent delay estimates from physical layout data process variation data as well as temperature and voltage variances How QuickSim Il Processes Circuit Activity Understanding how the simulator processes a simulation can help you use it more efficiently The fol
221. waveform databases Also they are removed from the keep list and any windows they may appear in and expressions and breakpoints that reference the invalid signal names are deleted The simulator lists in a status window any signals that are removed Reloading Models If you create a new version of a model such as by editing a schematic after you invoke the simulator you can bring the new version into the simulation by reloading the model Reloading models changes the design connectivity The effects of changing design connectivity are described in Effects of Design Changes beginning on page 2 43 You can use only one version of a model in a design viewpoint at any given time Therefore any model that you reload during a simulation is used for each instance that references that model For example assume that your simulation shows the schematic model of a counter device to be faulty and your design contains 24 instances of this counter You then correct the problem in the Design Architect and reload the model from the simulator to bring the new version into your simulation The simulator then uses the new version of the schematic model for each instance of this counter There are several approaches to reloading models as follows e You can reload a specific model which updates each instance that uses that specific model The simulator locates all affected instances and then re evaluates the design from the point of each updated instanc
222. y and then it calculates the actual state of the node using the final values from each category For example consider five connected output pins that have the following states OS XI XR 1Z and OI Using Table 2 3 the simulator would plot them as follows 1 First it would separate the signal states into the two categories 0S XR and 1Z and XI and OI 2 Next it would plot XR and OS to yield OS QuickSim II User s Manual V8 5_1 2 11 Simulator Accuracy Key Concepts 3 Then it would plot OS the result from step 2 and 1Z to yield OS 4 It would then plot XI and OI to yield XI 5 Last it would plot OS the result from step 3 and XI the result from step 4 to yield XS which is the actual state of the node Table 2 3 QuickSim II Node Resolution NOTES Q0 3 Signal value of logic 0 L a Signal value of logic 1 X 3 Signal value is unknown 0 or 1 a n Signal strength of high impedance Ro 3 Signal strength of resistive SSE Signal strength of strong Signal strength of indeterminate Timing Accuracy Timing accuracy in logic simulation is a function of three factors the simulator s basic unit of timing resolution the attributes associated with the modeling methods and special compensation routines QuickSim II User s Manual V8 5_ 1 Key Concepts How QuickSim Il Processes Circuit Acti
223. y values which you can insert or back annotate to the design for the final verification Before moving into your manufacturing processes you can further analyze your design using Mentor Graphics timing and test analysis applications The QuickPath static timing analyzer the QuickGrade II fault grader and the QuickFault II fault simulator which are optional Idea Station applications help determine your design s timing and testability requirements and performance QuickSim II Design Flow The flow through design creation and analysis is influenced by many factors and it can be unique for each development effort A company s internal requirements and use of external applications can dictate the tasks and the timing that the developer must adhere to Although there are many different design flows some generic tasks apply to almost all of them Figure 1 2 illustrates a generic design creation and simulation design flow 1 6 QuickSim II User s Manual V8 5_1 Overview of QuickSim Il QuickSim II Overview 6 Invoke 4 QuickSim Il A SimView gt y System E q Full Timing LA Functionality A Set Up Simulation Environment by 1 i a J L Obtain Models B Generate Refine 4 Stimulus 2 Capture Design v ii Run Simulation a Optionally C
224. you invoke the simulator is faster than setting them at the root level after the simulator is invoked This is because of the time it takes to propagate conditions to lower levels of the design Invoking from A Shell Invoking the simulator from a shell consists of entering a single command on the shell s command line The following example invokes the simulator on the design viewpoint of a component quicksim my_big_design my_vpt timing_mode typ This example includes the timing_mode switch and a timing mode value of typ This switch and value combination causes the simulation to include all typical timing values The quicksim shell command provides numerous switches so that you can invoke the simulator with exactly the conditions you desire Some general categories of conditions that you can issue are as follows Setup conditions restoring a saved setup object e Timing mode unit delays or full or linear min typ or max delays Delay scale value Constraint checks Spike model e Simulator resolution timestep value Debugging BLMs 3 10 QuickSim II User s Manual V8 5_1 Operating Procedures Running a Batch Simulation For specific information about the command line switches and the setup conditions that they apply refer to the quicksim command description in the Digital Simulators Reference Manual If your simulation does not require graphical interaction you can run a batch simulation Batch
225. ype default vi OK Cancel Figure 3 7 INIT Prompt Bar 2 Enter the appropriate State Value that you want to apply to your design 3 Use the stepper arrows to choose either default or classic initialization 4 Click on the OK button The simulator places the State Value on nets and pins in your design as an initial value If you choose classic initialization the simulator also runs without advancing the simulation clock until no events are pending to stabilize your design Suppressing Initialization Warnings When you perform and circuit initialization run after invocation or an initialize command some of the dynamic checks performed are unwarranted Memory Table model memory may loose its initialized values due to unknowns Xs on address and control signals Other warning messages that are issued as your design stabilizes may not be important To suppress warning messages and violation actions during your initialization run perform the following steps 1 Choose the following pulldown menu path Menu Bar gt Setup gt Kernel gt Change gt Warning Start The simulator then displays the Change Warning Start dialog box shown in Figure 3 8 QuickSim II User s Manual V8 5_1 3 25 Setting Up QuickSim Il Operating Procedures Change Warning Start Enable messages and or memory invalidations at time Which actions should be disabled until the above start time All User Spe

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