Help file for ex_RLC example
Contents
1. To illustrate this let s alter the capacitor value 1 Select the capacitor and select RMB gt Edit Model Properties This will bring up the Model Properties dialog Model Properties C1 capacitor ES Model Properties C1 capacitor General Parameters General Parameters Simulation Model Type REAL REAL LOW Library EDULIB v E CAPACITANCE Entity Architecture CAPACITOR w IDEAL w Eritity File Hame CAPACITOR WHO Architecture File Name Same as the Entity File Automatic format correction m cena The General tab displays information on the VHDL AMS library entity architecture and file name The Parameters tab allows you to change the value of any VHDL generic parameter 2 Change the CAP value to 100u as shown above and re simulate 3 When the simulation dialog appears select the Results tab and change the Viewer Loading Options to Append Display as shown below Simulation Control ex_rlc Simulations Muli A un Advanced Result Database Name Viewer Loading Options Load Onl ppend Display Wavetorms saved in Results D atah Replace Displa Time domain Analysis TopLevel W aveforms v TopLevel Waveforms v w Select Wravetorms for FFT Al 4 The new results will be automatically appended to your active graph Copyright Mentor Graphics Corporation 2003 5 Help on ex_RLC Sweeping Parameters With SystemVision it is also possible to auto2. The Advanced tab is used for advanced simulation settings normally not required 2 Click the OK button to run the simulation the Output Window will display the simulation progress and any error messages that may be issued Viewing Results 1 The simulation results will automatically be loaded into the waveform viewer upon completion of a successful simulation if not look in the Output Window for any error messages 2 Individual signals can be viewed by double clicking with the LMB or by using the drag and drop feature You can also plot a signal from the schematic by selecting the desired signal and using RMB gt Plot Waveform Use one of these methods to plot the sionals vinput and vload which should appear as shown below input load La 2 0m 12 0m 16 0m Time 3 3 Look at any other signals of interest Additional waveform viewing features are summarized below v Multiple graph windows and workspaces can be easily created using the menus or drag and drop V Signals can be deleted using the Delete key on your keyboard or by using the RMB gt Delete command on the signal name Markers can be place to view waveform coordinates S S The Measurement Tool can be used to measure various waveform characteristics more on this later Copyright Mentor Graphics Corporation 2003 4 Help on ex_RLC Modifying the Design With SystemVision it is easy to modify design parameters re simulate and compare results
3. EAL Automatic format correction 3 Click on the Parameters tab set AC_MAG to 1 and select OK 4 Re invoke the Simulation Control dialog Simulation Control ex_rlc Simulations Results Experiment Mame Operating Point Analysis Enable Time Domain Analysis Frequency Analysis L_ Enable Enable End Time 20m Freg Start C Enable FFT Freq Stop Enable the Frequency Analysis and run from 1 to 1meg frequency units are Hz Be sure to disable the parameter sweep in the Multi Run tab Click OK to run the analysis Plot the signal vload to see the frequency response te E Y1 Bf ab iviosa E Y2 Alb B Cphase vload 10 0 20 0 30 0 40 0 50 0 60 0 Magnitude dB 70 0 80 0 90 0 100 0 110 0 120 0 100 gt Out towed 1063 gt done Frequency Hz Copyright Mentor Graphics Corporation 2003 10 Help on ex_RLC Copyright Mentor Graphics Corporation 2003 11
4. Help on ex_RLC RLC Example Copyright Mentor Graphics Corporation 2003 All Rights Reserved This document contains information that is proprietary to Mentor Graphics Corporation The original recipient of this document may duplicate this document in whole or in part for internal business purposes only provided that this entire notice appears in all copies In duplicating any part of this document the recipient agrees to make every reasonable effort to prevent the unauthorized use and distribution of the proprietary information Copyright Mentor Graphics Corporation 2003 1 Help on ex_RLC Example ex_RLC Description This is a simple design containing a resistor inductor and capacitor driven by an ideal voltage source The models are written completely in the VHDL AMS modeling language use the RMB gt Push Language gt VHDL to view the source files The purpose of this example is to show how electrical building blocks can be easily written in VHDL AMS and simulated in SystemVision A picture of the schematic is shown below PU E 6 4 N Figure 1 RLC circuit Getting Started Users are encouraged to look through the following documents from the System Vision Help menu The RLC example is also used in the Getting Started with SystemVision tutorial Help gt SystemVision Help Topics This is the main online help resource with hyperlinks Topics include Introduction to SystemVision The User
5. Interface SystemVision Commands and How do I tips Help gt SystemVision Online Manuals gt Getting Started The Getting Started tutorial is provided to acquaint users with System Vision It is recommended that users run through this tutorial prior to running other examples Help gt SystemVision Online Manuals gt User s Manual The Users Manual is provided as a reference source for SystemVision Detailed explanations on tool usage are provided Help gt SystemVision OnlineManuals gt SystemVision Quick Reference Guide This document should be printed and used as a reference for running System Vision examples Help gt SystemVision Online Manuals gt VHDL AMS Quick Reference Guide This VHDL AMS reference succinctly reviews many VHDL AMS language features It is intended for those users interested in creating understanding VHDL AMS models Copyright Mentor Graphics Corporation 2003 2 Help on ex_RLC e For specific information on the Waveform Viewer select Help gt Quick Start and Help gt Tutorial gt Open Tutorial from the main Waveform Viewer window brief summary of the basic steps required to simulate the RLC circuit is given below as well as some design exploration suggestions Design Selection Viewing Editing 1 Make sure the ex_RLC project is loaded into SystemVision 2 From the Project tab click on Design Roots gt ex_rlc to open the schematic Simulating the circuit 1 From the P
6. matically sweep parameters over a specified range Doing so however requires you to switch to the Spice on top mode see Simulating with Spice tutorial for more details Before simulating SystemVision generates a netlist which is sent to the simulator for processing This netlist can be either in VHDL AMS or SPICE format For a nominal simulation there is no difference as to which netlist is used but in order to sweep parameters you must use a Spice netlist To change the netlist format select Simulation gt Testbench Options from the pulldown menu to display the following dialog Testbench Options ex_rlc Design Setup Compile Order Netlisting Option Spice VHDL Spice amp VHDL Simulation Options Toplevel File type 2 Spice Toplevel Filename Sakis Additional File List From this dialog set the Toplevel File Type to Spice you may still generate both Spice and VHDL netlists is desired Setting up Parametric Sweeps 1 Click Simulation gt Simulate to invoke the Simulation Control dialog 2 Click on the Multli Run tab and change Parameter Change Type to Sweep Values as shown below Simulation Control ex_rlc Parameter Value Parameter Edit Copyright Mentor Graphics Corporation 2003 6 Help on ex_RLC 3 Click on the Parameter Edit button to invoke the Sweep Parameter dialog Sweep Parameter Parameter E ycl cap Nominal alue Sweep Type Increment Sweep Start 10u Swee
7. opyright Mentor Graphics Corporation 2003 4 Help on ex_RLC 2 The sign and symbol next to the signal name indicates it is a compound waveform Each member can also be displayed by clicking on the sign to expand and plotting individually 3 Placing your cursor over one of the members in the graph area will display the individual member name along with the parameter value s used for that simulation run as shown above 4 Placing your cursor over the signal name and selecting RMB gt Parameter Table will allow you to view the parameter values for all the runs Parameter Table Waveform ex_rle 1 vload D S EtC1 CAF ates a ates v 6 ES ales y Performing a Measurement 1 Click on the Measurement Tool in the toolbar to bring up the measurement dialog Measurement Tool settings Measurement All Types r Risetime r Source Wawveformis Measurement Setup Thresholds Topline ee 5 1e Baseline Automates xl Lower Upper 10 90 M Levels are Relative to the Topline and Baseline Measurement Results Annotate Wwaveformis with Result Markers Apply Measurementto Entire Waveform x Remove All Previous Risetime Results Apply close Help Copyright Mentor Graphics Corporation 2003 8 Help on ex_RLC 2 Select the Risetime measurement from the pulldown list 3 Set the Source Wavewform to the compound waveform vload 4 Leave the thresholds set at au
8. p Stop 100u Sweep Increment 1 Cua Replace current sweep parameters Select Parameter Select YHOL Instance Parameters kd pel w io yli ic yh ind pr rez yy_pulse ac_mag wy pulse ac phase pe pulse delay pe pulse initial pe pulse period pe pulsel pulse pe pulse H2p pe pulse tp pe pulse width 4 Click on the browse button to select the capacitance yc1 cap Note Since this design consists exclusively of VHDL AMS models you need to set the Select field to VHDL Instance Parameters 5 Fill in the rest of the Sweep Parameter dialog as shown above and select OK to continue 6 The Simulation Control dialog will be automatically updated with the sweep information Click OK to continue with the simulation The output window will display the progress of each simulation run Viewing Multi Run Results Again the results will automatically be loaded into the waveform viewer They will be in the form of compound multi member waveforms 1 Plot the signal vload as shown below use LMB to zoom in Mentor Graphics Waveform Analyzer File Edit View Format Cursor Window Help SSH S ex Boe pRB rh QAQQANER BEAD Waveform List x Currently Open Databases E Gq ex_rie 1 Contains ut A vinput Ea vioad Voltage Vv 2 yload_10 ymid 0 yet 0 yi1 0 yr yv_pulse1 H workspace1 10m 15m 20m 25m 30m 35m 40m 44 Time 5 Ki E Data X 1 70000m Y1 3 60644 C
9. tomatic 5 Select Annotate Waveforms to annotate the graph with a measurement marker and click Apply 6 Note the marker can be moved from one member to the next 7 Move your cursor over the marker and select RMB gt Measurement Results to view a table of the measurement results 8 Return to the Measurement Tool and select Plot New Waveform 9 Click Apply will display a new waveform as shown below Risetime vload 347 52633U on d Ti ql LE 10 04 20 04 20 04 40 04 50 0u 60 1 50 000000 Parameter E YC1 CAP 10 This automatically calculates the risetime of each individual member and plots it as a function of the capacitance Placing a cursor will display the risetime and associated capacitance value Performing a Frequency Analysis With SystemVision it is also possible to perform a small signal frequency AC analysis Before running a frequency analysis you will need to add an AC component to the voltage source Typically this involves normalizing the AC magnitude to 1 and AC phase to 0 for the desired input 1 Select the voltage source on the schematic 2 Select RMB gt Edit Model Properties to invoke the model properties dialog Copyright Mentor Graphics Corporation 2003 J Help on ex_RLC Model Properties Y_PULSE1 v_pulse EJ Parameterz Default TIZP TIME TP21I TIME WIDTH TIME PERICO TIME PLILSE VOLTAGE Al MAG VOLTAGE INITIAL VOLTAGE DELAY TIME AC PHASE R
10. ull down menu select Simulation gt Simulate to invoke the Simulation Control window there is also a simulation icon available on the iconbar The VHDL AMS files will be compiled as necessaty v The Simulations tab is for the basic settings and to enable disable the desired analyses Enable the Time Domain Analysis and set End Time to 20m as shown Simulation Control ex_rlc Simulations Results Multi Aun Advanced Esperment Hame exrlc cmd w Operating Point Analysis Enable Time Domain Analysis Frequency Analysis Enable 5etup i _ Enable End Time Freg Start e Enable FFT Fred Stop Y The Results tab is used to select the signals for viewing The default selection is TopLevel Waveforms which will save all signals at the highest level of hierarchy Since this is a small design All Signals was selected for convenience You can also choose Selected Waveforms and click on the browse button to select individual signals Simulation Control ex_rlc Simulations Results Multi Run Advanced Result Database Name Viewer Loading Options ex_tic Load Only v Waveforms saved in Results Database Time domain nalysis Frequency Analysis All Waveforms v TopLevel Waveforms YW TopLevel Waveforms All Waveforms Selected Waveforms lJ None Copyright Mentor Graphics Corporation 2003 3 Help on ex_RLC v The Multi Run tab is for performing parametric variations more on this later v
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