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Programmer`s Manual Digital Gamma Finder (DGF)

1. Usage example Download DSP parameters to the current DGF module DSP Values is a pointe here r pointing to the DSP parameters no need to specify file name C_Dgf4c Buffer IO DSP Values 0 0 Read DSP memory values from the current DGF module Memory Values is a poin here C Dgf4c_ B ter pointing to the memory block no need to specify file name uffer IO Memory Values 1 1 W 12 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved Options for Compiling DGF 4C C Driver DGF 4C C Driver can be compiled as either a WaveMetrics Igor XOP file which is currently used in the DGF 4C Viewer or a standalone C Library The latter option can be used by advanced users to integrate DGF modules into their own data acquisition systems The following table summarizes the required files for these two options Table 2 3 Two options for compiling the DGF 4C C Driver Compilation Required Files Option C source files C header files Library files boot c camac c camacdll c booth enc pcice32_n1 lib Standalone ee globals h sharedfiles h 3 A CC32 c Communication c ae pcice32_n1 dll Clay dgf4c c c utilities c utilities cesa wnaspi32 dll oe i vpcic32d h Winaspi h Ps boot c camac c camacdll c boot h Camacdll h CC32 c Communication c globals h sharedfiles h pcice32_n1 lib Igor XOP dgf4c_c c utilities c utilities h Libcc32 h pcice32
2. Wait 50ms Boot Write TSAR FADA 1 1 DSP Write Memory DSPcode 2 DSPcode 3 F 16 A 0 DSPcode N Write TSAR FADA 1 0 Write Memory DSPcode 0 DSPcode 1 F 16 A 0 Do not read from the modules before the system FPGAs of all modules in the crate are configured because unconfigured system FPGAs may interfere with the CAMAC communication In particular avoid working with only one out of several powered modules unless all modules are configured Revision D and revision E modules use the same System FPGA configuration and DSP code but different Trigger Filter FPGA configuration files In mixed systems to decide which files to download read the version register from the interface FPGA issue F 17 A 8 The hardware version is encoded in the lower 4 bits of the returned data word revision D 3 revision E 4 To check the success of the downloads issue a Read ICSR command F 1 A 8 If the return value is zero all downloads were successful If not the bit pattern contains information which download did not succeed if bit 0 is 1 the system FPGA is not configured if any of bits 4 7 is 1 the trigger filter FPGA for channel 0 3 is not configured After initialization the switchbus registers in the ICSR have to be set in order to properly terminate trigger signals To set the ICSR register issue a Write ICSR command with the bit pattern that matches your system see Table 9 7 in User s Manual Fo
3. s Manual V3 04 XIA 2004 All rights reserved UserRunInit This function is called at each run start for new runs as well as for resumed runs The purpose is to precompute often needed variables and pointers here and make them available to the routines that are being called on an event by event basis The variables in question would be those that depend on settings that may change in between runs UserChannel This function is called for every event and every DGF 4C channel for which data are reported and for which bit 0 of the channel CSR_B ChannelCSRB variable has been set It is called after all regular event processing for this channel has finished but before the energy has been histogrammed UserEvent This function is called after all event processing for this particular event has finished It may be used as an event finish routine or for purposes where the event as a whole is to be examined UserRunFinish This routine is called after the run has ended but before the host computer is notified of that fact Its purpose is to update run summary information Global variables UserIn 16 16 words of input data also visible to host UserOut 16 16 words of output data also visible to host When entering UserChannel the following globals have been set by the DSP Atstart Address of 1st word of the ADC trace Tlen Length of the ADC trace Energy Pulse height of the event ChanNum Current channel number GSLTtimeA high w
4. GLOBAL_DATA_NAMES used to transfer parameters applicable to individual SYNCH_WAIT and IN_SYNCH used to broadcast SYNCH_WAIT or IN SYNCH Element of array User_Var_Names see Table 3 1 used to transfer parameters Global Data Values Find Xact Global DATA Match MODULE _CSRA 0x2400 download MODULE _CSRA to DSP C_Dgf4c User Par IO Global Data Values GLOBAL DATA NAMES 0 set user variable ENERGY RISETIME to 6 0 us User Var Values Find Xact_User Match ENERGY RISETIME 6 0 download ENERGY RISETIME to DSP C Dgf4c User Par IO User Var Values ENERGY RISETIME 0 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved C_Dgf4c_Acquire_Data Syntax long C_Dgf4c Acquire Data long Run_Type Data acquisition run type unsigned int User data An unsigned 32 bit integer array containing the data to be transferred char file name Name of the file used to store list mode or histogram data Description Use this function to acquire ADC traces MCA spectrum or list mode data The string variable file_name needs to be specified when stopping a MCA run or list mode run in order to save the data into a file or when calling those special list mode runs to retrieve list mode data from a saved list mode data file In all other cases file name can be specified as an empty string The unsigned 32 bit integer array User_data is only used for acquiring ADC traces control ta
5. 24 sum the total number of traces for the two modules traceposlen long malloc totaltraces 3 4 allocate memory to hold position and length information C_Dgf4c_ Acquire Data 0x5001 traceposlen file name_1 locate traces Trace0 unsigned short malloc traceposlen 1 2 allocate memory to hold the first trace Trace0 0 traceposlen 0 position of the first trace Trace0 1 traceposlen 1 length of the first trace C_Dgf4c_ Acquire Data 0x5002 Trace0 file name_1 read out the first trace and put it into trace0 20 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved 4 User Accessible Variables User parameters are stored in the data memory space of the on board DSP The organization is that of a linear memory with 16 bit words Subsequent memory locations are indicated by increasing addresses The data memory space as seen by the host computer starts at 0x4000 There are two sets of user accessible parameters 256 words in data memory are used to store input parameters These can and must be set properly by the user application A second set of 160 words is used for results furnished by the DGF 4C module These should not be overwritten As of this writing the start address for the input parameter block is InParAddr 0x4000 and for the output parameter block it is OutParAddr 0x4100 i e the two blocks are contiguous in memory space We provide an ASCII file named DGFcodeE var which conta
6. Carlo from the host computer For this to work the module has to halt the background activity of continuous base line measuring Next data have to be downloaded and the event processing started When done the host can read the results from the known address The process is fairly simple The host writes the length of the data block that is to be downloaded into the variable XDATLENGTH Then the data are written to the linear I O buffer the address and length of which are given in the variables AOUTBUFFER and LOUTBUFFER Next the user starts a data run and reads the results after the run has ended 47 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved 7 Appendix B Control DGF 4C modules using CAMAC commands This appendix includes the CAMAC commands which appeared in earlier versions of DGF manuals Version 2 80 or earlier Although DGF users are recommended to use to DGF 4C C Driver to program their DGF modules CAMAC commands are the other alternative to control the modules 7 1 CAMAC interface The CAMAC interface through which the host communicates with the DGF 4C is implemented in its own FPGA The configuration of this gate array is stored in a PROM which is placed in the only DIP 8 IC socket on the DGF 4C board The interface conforms to the regular CAMAC standard as well as the newer Level 1 fast CAMAC with a cycle time of 400 ns per read operation The interface moves 16 bit data words at a time The upper 8
7. ControlTask 10 reading out the I O buffer after every run The 3 bytes of a histogram entry BO LSB B1 and B2 are mapped onto two 16 bit words W0 B1 B0 and W1 0x00 B2 in the I O buffer WO occupies the lower memory address and BO and B2 form the least significant bytes of WO W1 Write histogram memory 1 page Writes the DSP s main I O buffer into the first page of external memory The target channel is specified by HOSTIO Write histogram memory subsequent pages Writes the DSP s main I O buffer into a subsequent page of external memory The page is specified by an internal page counter The page counter is set to zero first page in a ControlTaks 11 and incremented after each ControlTask 11 or 12 The byte organization is the same as described at the end of Control task 10 reserved First ADC Calibration DGF 4C revision D only Subsequent ADC Calibrations DGF 4C revision D only Contact XIA for details 42 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved 6 Appendix A User supplied DSP code 6 1 Introduction It is possible for users to enhance the capabilities of the DGF 4C by adding their own DSP code XIA provides an interface on the DSP level and has built support for this into the DGF 4C Viewer The following sections describe the interfaces and support features 6 2 The development environment For the DSP code development XIA uses and recommends version 5 or 6 of the assembler a
8. DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved C_Dgf4c_Boot_System Syntax long C Dgf4c Boot System long Boot Pattern The DGF boot pattern Description Use this function to boot all DGF modules in the system Before booting the modules it initializes the CAMAC communication port and if CAMAC Master is going to be used loads the CAMAC station number register Parameter description Boot_Pattern is a bit mask used to control the boot pattern of DGF modules Bit 0 Boot system FPGA Bit 1 Boot FIPPI Bit 2 Boot DSP Bit 3 Load DSP parameters Bit 4 Apply DSP parameters call Set_ DACs and Program _FIPPI Under most of the circumstances all the above tasks should be executed to initialize the DGF modules i e the Boot Pattern should be Ox1F Return values Value Description Error Handling 0 Success None lt 0 Boot failed Check the error message reported by the driver Usage example boot DGF 4C modules ret C Dgf4c Boot System 0x1F if ret lt 0 error handling 5 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved C_Dgf4c_User_Par_lO Syntax long C Dgf4c User Par IO double User Par Values A double precision array containing the user parameters to be transferred char User Par Name A string variable which designates which type of user parameters to be transferred long direction Transfer di
9. Energy values are all reported as unsigned 16 bit numbers and a pulse step covering the full range of the ADC would be reported as having amplitude of 65535 That is an LSB of an energy value corresponds to 1 4 of an original ADC unit for 14 bit ADCs or to 1 16 of an original ADC unit for 12 bit ADC units Waveform data are reported as untriggered traces in the Oscilloscope of the DGF4C Viewer cf control task 4 or as triggered traces in the list mode trace display of the DGF4C Viewer during regular data acquisition Revision D and E DGFs report the waveforms in the Oscilloscope as 14 bit numbers and the list mode trace as 16 bit numbers The trigger threshold set by the FASTTHRESH variable is always in units of the 12 bit ADC times the length of the trigger filter measured in 25ns ticks The Ramp Offset DAC control task 3 always reports results in units of the 12 bit ADC The following example may illuminate this Assume a DC offset such that it measures 400 units on the 12 bit ADC Assume a step pulse with a pulse height of 1000 units as measured by the 12 bit ADC Oscilloscope shows baseline at 1600 The pulse step would show as a jump from 1600 to 5600 in the Oscilloscope display Traces acquired in list mode data runs would show a jump from 6400 to 22400 The energy would be reported as 1000 For a trigger filter length of 100ns FastLength 4 and FASTTHRESH 100 the trigger threshold will be 25 units of the 12 bit ADC This value
10. Files 3 All Files 4 C XIA DGF4C DSP DGFcodeE Ist File of DSP memory variable names All Files 5 C XTA DGF4C Firmware fdgf4c4D bin FIPPI configuration for Module 1 Rev D All Files 6 C XTA DGF4C Firmware fdgf4c4E bin FIPPI configuration for Module 2 Rev E The global variable array Module Global Values also needs to be initialized before C Driver functions can be called to start the initialization Table 3 3 lists those global variables Table 3 3 Initialization of Module_Global_ Values Module Global Names Module Global Values Note NUMBER MODULES 2 The total number of DGF 4C modules CONTROLLER ID 0 0 J73A 1 CC32 2 offline SCSI BUS 0 Usually 0 or 1 could be 0 to 7 CRATE ID 1 The crate number on the front panel dial of the controller CAMAC MASTER 1 1 enable 0 disable use master controller FAST CAMAC 0 1 enable 0 disable use level 1 fast CAMAC transfer LAM_ ENABLE 0 1 enable 0 disable use LAM interrupt SLOT_WAVE 0 24 CAMAC master controller SLOT WAVE 1 3 Module 1 sits in slot 3 SLOT _WAVE 2 11 Module 2 sits in slot 11 3 1 2 Boot DGF 4C modules The boot procedure for DGF 4C modules includes the following steps First all the global parameter names should be downloaded by calling function C_Dgf4c_Hand_Down_Names Then function C_Dgf4c User Par IO should be called to
11. M are preset and guaranteed as follows LO L7 0 MO 0 MI 1 M2 1 M4 0 M5 1 M6 1 M3 and M7 have no guaranteed values UserBegin UserRunInit and UserRunFinish No further restrictions but user code must leave the associated registers listed above in exactly this state when exiting UserChannel 15 16 17 These registers may not even temporarily be overwritten because there L5 L6 are interrupt functions which depend on the contents of these registers M0 M1 M2 M4 M5 M6 10 11 13 14 These registers may be altered but must be restored on exit L0 L1 L2 L3 L4 L7 I2 These registers may be altered and need not be restored M3 M7 UserEvent 15 16 17 These registers may not even temporarily be overwritten because there L5 L6 are interrupt functions which depend on the contents of these registers M0 M1 M2 M4 M5 M6 14 These registers may be altered but must be restored on exit L0 L1 L2 L3 L4 L7 10 11 12 13 These registers may be altered and need not be restored M3 M7 46 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved 6 5 Debugging tools Besides the debugging tools that are accessible through the DGF 4C Viewer it is also possible to download data into the DGF data buffers and call the event processing routine This allows for an in situ test of the newly written code and allows exploring the valid parameter space systematically or through a Monte
12. Once a new variable has been written to DSP memory it has to be activated by starting a run with RunTask 0 and ControlTask 5 SLOWLENGTH The rise time of the energy filter depends on SlowLength RiseTime SlowLength 2 Decimation 25ns SLOWGAP The flat top of the energy filter depends on SlowGap FlatTop SlowGap 2 Decimation 25ns There is a constraint concerning the sum value of the two parameters SlowLength SlowGap lt 32 FASTLENGTH The rise time of the trigger filter depends on FastLength RiseTime FastLength 25ns Note the constraint FastLength lt 32 FASTGAP The flat top of the trigger filter depends on FastGap FlatTop FastGap 25ns There is a constraint concerning the sum value of the two parameters FastLength FastGap lt 32 FASTADCTHR This value is used by the previous versions of DGF 4C Viewer to store the fast trigger threshold in ADC units The DGF 4C module does not use this value 29 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved For revision D and revision E modules one LSB of this variable corresponds to 4 LSB of the reported waveform data which are 14 bit numbers For DGF 4C Viewer 3 00 or later this value is not in use any more FASTTHRESH This is the trigger threshold used by the trigger filter FPGA The value relates to a trigger threshold through the formula FASTTHRESH TriggerThreshold FASTLENGTH The TriggerThreshold can be set on the Settings tab o
13. active only while a data acquisition run is in progress Comparing the run time with the real time allows judging the overhead due to data readout Compute the run time using the following formula RunTime RunTimeA 6553612 RunTimeB 65536 RunTimeC 25ns GSLTTIMEA GSLTTIMEB GSLTTIMEC Signal arrival time of a logic 0 gt 1 transition at the GSLT front panel LEMO input The time latched is the real time at that moment NUMEVENTSA NUMEVENTSB Number of valid events serviced by the DSP Again the high word carries the suffix A and the low word the suffix B DSPERROR This variable reports error conditions 0 NOERROR no error 1 RUNTYPEERROR unsupported RunType 2 RAMPDACERROR Baseline measurement failed SYNCHDONE This variable can be set to 1 to force the DSP out of an infinite loop caused by a malfunctioning Busy Synch loop when a run start request was issued 35 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved with SYNCHWAIT 1 BUFHEADLEN At the beginning of each run the DSP writes a buffer header to the I O buffer BufHeadLen is the length of that header Currently BUFHEADLEN is 6 but this value should not be hardcoded it should be read from the DSP to ensure upgrade compatibility EVENTHEADLEN For each event in the I O buffer or the Level 1 buffer there is an event header containing time and hit pattern information EventHeadLen is the length of that header Currently EVEN
14. bit 1 to 1 ie NewRun command cmd setbit 0 cmd set bit 0 to 1 ie start a new run Write CSR cmd issue NewRun command cemd clrbit 1 cmd clear bit 1 of cmd use cmd for the ResumeRun command for k 1 k lt Nruns k while Read_CSRQ AND 0x2000 y wait until run has ended use bit wise AND Read data and save to file Write_CSR cmd issue ResumeRun command The transfer from external memory to DSP memory is accomplished by control runs as outlined in the pseudocode in Table 7 5 The DSP variable HOSTIO specifies the channel to read For the first page of the spectrum start a run with RUNTASK 0 CONTROLTASK 9 For subsequent pages CONTROLTASK 10 The page number is incremented automatically by the DSP in every control run 53 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved Table 7 5 Accessing spectrum memory Address GetAddress AOUTBUFFER find the variable AOUTBUFFER Write _TSAR Address AOUT Read_Data 1 read the value of AOUTBUFFER and store in AOUT Address GetAddress LOUTBUFFER find the variable LOUTBUFFER Write_TSAR Address LOUT Read_Data 1 read the value of LOUTBUFFER and store in LOUT Address GetAddress HOSTIO Write_TSAR Address Write_Data channel 1 write 1 word setting HOSTIO to selected channel Address GetAddress RUNTASK Write_TSAR Address Write Data 0 1 write 1 word setting RUNTASK to 0 Address GetAddress CONTROL
15. on the other parameter Name l All Files is a string array which has MAX NUMBER OF MODULES 5 elements Currently MAX NUMBER OF MODULES is defined as 24 The first five elements of All Files are the name of system FPGA file DSP code binary file DSP I O parameter values file DSP code I O variable names file and DSP code memory variable names file The remaining elements are FIPPI file names for each module All file names should contain the complete path name Note all modules use the same system FPGA and DSP codes but could use different FIPPI files An example of All Files is given in Table 3 2 Module_Global_Names is a string array containing global variable names which are applicable to all modules e g number of modules in the crate the CAMAC controller type the SCSI number and the CAMAC crate ID etc Module _Global_Names currently can hold 64 names If less than 64 names are needed which is the current case the remaining names should be defined as empty strings A detailed description of Module Global Names is given in Table 3 6 Global_Data_Names is a string array containing global variable names which are applicable to each individual module e g module number module CSR coincidence pattern and run type etc Global Data Names can currently hold 64 names If less than 64 names are needed which is the current case the remaining names should be defined as empty strings A detailed description of Global Data Names is gi
16. there are 16 different hit patterns and each can be individually selected or marked for rejection by setting the appropriate bit in the COINCPATTERN mask Consider the 4 bit hit pattern 1010 The two 1 s indicate that channel 3 MSB and channel have reported a hit Channels 2 and 0 did not The 4 bit word reads as 10 decimal If this hit pattern qualifies as an acceptable event set bit 10 in the COINCPATTERN to 1 The 16 bit in COINCPATTERN cover all combinations Setting COINCPATTERN to OxFFFF causes the DGF to accept any hit pattern as valid In the DGF 4C Viewer this variable can be set in the Coincidence Pattern Edit Panel reachable through the Settings tab by clicking on Edit next to the Coinc Pattern entry COINCWAIT Duration of the coincidence time window in 25ns clock ticks The actual coincidence window is 50ns wider than the value determined by COINCWAIT For this feature to work bit no 1 of the ChannelCSRA of the involved channels should be cleared This ensures that the DSP can at the end of the coincidence window suppress further hits reporting by late channels In the DGF 4C Viewer this bit is set or cleared in line 1 of the Channel CSRA Edit Panel The line has the title Measure individual live time Make sure it is unchecked so the DSP globally controls FPGA triggering and live time measurements When acquiring long waveforms it may be necessary to delay DSP data reading to ensure that the FIFOs will contain valid
17. 0 dummy file name 1 stop run and save list mode run data k if k gt Nruns break C_Degf4c_Acquire_Data 0x2100 dummy issue ResumeRun command while 1 C_Dgf4c_ Acquire Data 0x3100 dummy file name 2 store energy histogram The list mode data in the I O buffer can be written in a number of formats User code should access three DSP variables BUFHEADLEN EVENTHEADLEN and CHANHEADLEN in the settings file of a particular run to navigate through the data set To facilitate the access of list mode data after a run is finished the DGF 4C C Driver provides several utility routines to parse the list mode data saved in the output file and read out the waveform energy or PSA values of each event The code in Table 3 9 shows how to read waveforms from a list mode file 19 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved Table 3 9 An Example Code Showing How to Access List Mode Data C_Dgf4c_Acquire_Data 0x1100 dummy start a new list mode run while C_Dgf4c_Acquire_Data 0x4100 dummy wait until run has ended C_Dgf4c_Acquire_Data 0x6100 dummy file name_1 store list mode data in a file C_Dgf4c_ Acquire Data 0x3100 dummy file _name_2 store energy histogram in a file C_Dgf4c_ Acquire _Data 0x5100 listmodewave file name_1 parse list mode file totaltraces 0 for i 0 1 lt 2 i totaltraces listmodewave i
18. 24 bit word first followed by a second write in which the lower 8 bits 50 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved carry the lower portion of the 24 bit word For reads you will receive the higher 16 bits in the first word and the lower 8 bits of the 24 bit word in the lower 8 bits of the second read 7 4 Using level 1 fast CAMAC data reads Fast CAMAC reads are implemented for data reads from DSP memory and can be applied to reading list mode and histogram data It is important to note that some CAMAC controllers do not deassert the N line at the end of the fast CAMAC data transfer In such a case the red front panel LED will remain lit after the transfer In fact the controller may deassert the N line only after the next regular CAMAC command has been completed Therefore you have to issue a dummy command to the module say Read_CSR to make the controller deassert the N line 7 5 Accessing DSP variables Setting individual DSP variables in general requires a very good understanding of how the DGF 4C works However you may want to be able to change some of the settings using your own host computer The best strategy is to create an image of the first 256 data words of the DSP memory in your host computer and then download the whole set Since your change of variables may require a reprogramming of the DGF DACs or the trigger filter FPGAs you should call the relevant DSP routines You may also want to make sure y
19. 4C C Driver 16 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved Table 3 5 An Example Code to Illustrating How to Set DSP Variables set global data variable MODULE_CSRA to 0x2400 Global_Data_Values Find_Xact Global DATA Match MODULE_CSRA 0x2400 download MODULE_CSRA to DSP C_Dgf4c User Par IO Global_Data Values GLOBAL DATA NAMES 0 set user variable ENERGY _RISETIME to 6 0 us User_Var_Values Find_Xact_User_Match ENERGY_RISETIME 6 0 download ENERGY _RISETIME to DSP C_Dgf4c User Par IO User Var Values ENERGY_RISETIME 0 Table 3 6 Descriptions of Global Variables in DGF 4C Module_Global_Names VO Type Unit Corresponding DSP Legal Range of Variables Variable Values NUMBER_MODULES Read Write N A N A 1 Max of Modules CONTROLLER ID Read Write N A N A Check Controller SCSI BUS Read Write N A N A Check SCSI bus CRATE ID Read Write N A N A Check Crate CAMAC MASTER Read Write N A N A 0orl FAST CAMAC Read Write N A N A Oorl LAM ENABLE Read Write N A N A Oorl C LIBRARY RELEASE Read only NA N A N A C LIBRARY BUILD Read only N A N A N A SLOT WAVE Read Write N A N A N A Global_Data_Names VO Type Unit Corresp
20. 5ns if XWAIT gt 11 XWAIT has to be multiple of 4 The following variables affect internal MCA histogramming of the DGF 4C module ENERGYLOW Start energy histogram at ENERGYLOW LOG2EBIN This variable controls the binning of the histogram Energy values are calculated to 16 bits precision The LSB corresponds to 1 16 of a 12 bit ADC unit or 1 4 of a 14 bit ADC for revision E modules The DGFs 32 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved CFDTHR however do not have enough histogram memory available to record 64K spectra nor would this always be desirable The user is therefore free to choose a lower cutoff for the spectrum EnergyLow and control the binning Observe the following formula to find to which MCA bin a value of Energy will contribute MCAbin Energy EnergyLow 2 Log2Ebin As can be seen Log2Ebin should be a negative number to achieve the correct behaviour At run start the DSP program ensures that Log2Ebin is indeed negative by replacing the stored value by abs Log2Ebin The histogramming routine of the DSP takes care of spectrum overflows and underflows This sets the threshold of the software constant fraction discriminator The threshold fraction f is encoded as Round f 65536 with 0 lt f lt 1 PSAOFFSET PSALENGTH When recording traces and requiring any pulse shape analysis by the DSP these two parameters govern the range over which the analysis will be applied Th
21. ASE DSP software release number DSPBUILD DSP software build number The following channel variables contain run statistics Again the variable names carry the channel number as a suffix For example the LIVETIME words for channel 2 are LIVETIMEA2 LIVETIMEB2 LIVETIMEC2 Channel numbers run from 0 to 3 LIVETIMEA LIVETIMEB LIVETIMEC Total live time as measured by the trigger filter FPGA of that channel It excludes times during which the FPGA was prevented from sending triggers due to ongoing DSP data reads or when the run was stopped Convert the three LiveTime words into a live time using the formula LiveTime LiveTimeA 6553612 LiveTimeB 65536 LiveTimeC 0 400us 37 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved FASTPEAKSA The number of events detected by the fast filter is FASTPEAKSB NumEvents FASTPEAKSA 65536 FASTPEAKSB ADCPERDACA Gain variable ADCPERDACB Both words currently unused but reserved 4 3 ADC data The revision E DGF 4C modules employ 14 bit waveform digitizing ADCs while revision D DGF 4C modules employ 12 bit ADCs All modules are operating at 40MSPS Hence the natural units are 25ns for a time step Depending on which DGF 4C modules being used the original waveform data are either 14 bit unsigned numbers ranging from 0 to 16383 or 12 bit unsigned numbers ranging from 0 to 4095 Derived quantities however are reported by the DGF to higher than 12 bit precision
22. Double precision User_Par_Name Global Data Values 64x24 Double precision The way to fill the User_Values array is to fill the channel first then the module First 64 values are stored in the array for channel 0 and then repeat this for other three channels At that time 64x4 values have been filled for module 1 Then repeat this for the remaining 6 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved modules For the Global _Data Values array first store 64 values for module 1 and then repeat this for other modules User_Par_Name is a string variable which selects what type of parameters to be transferred It can be one of the following four choices 1 MODULE_GLOBAL_NAMES used to transfer parameters applicable to all modules 2 modules 3 to all modules 4 applicable to an individual channel of an individual module direction indicates the transfer direction of parameters 0 download write parameters from the user interface to the driver 1 upload read parameters from the driver to the user interface Return values Value Description Error Handling 0 Success None lt 0 Transfer failed Check the error message reported by the driver Usage example set global data variable MODULI E CSRA to 0x2400
23. P program though it may slow it down Writing to the TSAR transfers the TSAR content to a DMA address register in the DSP With each read or write the address register in the DSP is incremented The TSAR in the interface FPGA however remains unaltered Therefore if you want to read from the same memory location twice you have to write the TSAR again Table 7 2 List of CAMAC commands for revision D and revision E DGFs Refer to subsection 7 4 concerning peculiarities of the fast level 1 CAMAC reads Command F A code Action Write CSR F 17 A 0 Write to CSR Read CSR F 1 A 0 Read CSR Write ICSR F 17 A 8 Write to ICSR Read ICSR F 1 A 9 Read ICSR Write TSAR F 17 AQ Write to TSAR Read TSAR F 1 A 1 Read TSAR Write WrdCnt F 17 A 2 Write to word count register Read WrdCnt F 17 A 2 Read word count register Write Data F 16 A 0 Write data to DSP memory Read Data F 0 A 0 Read Data fast F 5 A 0 Read data from DSP memory Level 1 fast CAMAC DSP data read Secondly data and program memory of the DSP are organized into different banks with different word length Data memory is 16 bit wide and you read one location with each CAMAC cycle The program memory is 24 bit wide The DSP uses a 16 bit data bus and has to transfer the 24 bit words in two CAMAC cycles For writes you have to write the higher 16 bits of the
24. Procedure for downloading and activating a new set of parameters cmd Read_CSR cmd CLRBIT 0 cmd clear bit 0 Write CSR cmd stop run without overwriting other bits while Read_CSR amp 0x2000 Wait for end of run Write TSAR 0x4000 start of data memory Write _Data DSPvalues 256 write 256 words Address GetAddress RUNTASK Write_TSAR Address Write _Data 0 1 write 1 word setting RUNTASK to 0 Address GetAddress CONTROLTASK Write_TSAR Address Write _Data 0 1 write 1 word setting CONTROLTASK to 0 cmd Read_CSR cmd SETBIT 0 cmd set bit O of cmd to 1 Write CSR cmd start run without overwriting other bits while Read_CSR amp 0x2000 wait until DACs are reprogrammed Address GetAddress CONTROLTASK Write_TSAR Address Write _Data 5 1 write 1 word setting CONTROLTASK to 5 Address GetAddress AOUTBUFFER Rev D only obtain address of I O buffer Write_TSAR Address Write_Data calibration N_ calibration Rev D only write ADC calibration file cmd Read_CSR cmd SETBIT 0 cmd set bit 0 of Ret to 1 Write CSR cmd start run without overwriting other bits while Read_CSR amp 0x2000 wait until trigger filter FPGAs are reprogrammed 52 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved Table 7 4 Command sequence for multiple runs in a row cmd Read CSR read value of interface CSR cmd setbit 1 cmd set
25. Programmer s Manual Digital Gamma Finder DGF DGF 4C Version 3 04 January 2004 X Ray Instrumentation Associates 8450 Central Ave Newark CA 94560 USA Phone 510 494 9020 Fax 510 494 9040 http www xia com Disclaimer Information furnished by XIA is believed to be accurate and reliable However XIA assumes no responsibility for its use or for any infringement of patents or other rights of third parties which may result from its use No license is granted by implication or otherwise under the patent rights of XIA XIA reserves the right to change the DGF product its documentation and the supporting software without prior notice N Nn COV ELV IC Wei rite BASIE UE A UE ARR TLS EE ASD EE AA he as Ban 1 DG ACC Div aia ad iS LI aan aa 1 Detac Hand Down Names ui dd id ita rc 3 OS GIA Boot Nat tn A daa TA 5 C Dette User Par TO e do aes 6 Co Dette Acquite Dia tila 8 C Det4c Set Current Mod Wann aid di 10 Dgf4e O oak al Za ahr eaten A nad sea Rasa elt la aha 11 Options for Compiling DGF 4C C DriVeL ooonooccncccnoccconncconocononono conc ccoo occ nono n cono cconn cnn ncnnnss 13 Control DGF 4C Modules via DGF 4C C DrIiVeL ooooonicccccococonoconnnonnnconccconocnnn nono nono ncnnns 14 Dek a nitiali ati on io 14 3 1 1 nitialize global variables dt cuumeauceanv enews 14 3 1 2 Boot DGE AC MmOdules aiii 15 32 Setting DSP variables an A Aa 16 3 3 Access spectrum memory or list mode data oooo
26. TASK Write_TSAR Address Write Data 9 1 write 1 word setting CONTROLTASK to 9 cmd Read_CSR cmd SETBIT 0 cmd set bit O of cmd to 1 Write_CSR cmd start run without overwriting other bits while Read_CSR amp 0x2000 wait until 1 spectrum page is transferred to I O buffer Write TSAR AOUT write the buffer start address Read _Data DMCA LOUT read LOUT 16 bit words into the array DMCA for k 0 k lt xLOUT k 2 reconstruct the MCA entry EMCA k DMCA 2 k 1 8 0x00FF 256 DMCA 2 k forG 1 j lt 7 j 1 repeat for following 7 pages Address GetAddress CONTROLTASK with CONROLTASK 10 Write_TSAR Address Write_Data 10 1 write 1 word setting CONTROLTASK to 10 cmd Read_CSR cmd SETBIT 0 cmd set bit 0 of cmd to 1 Write_CSR cmd start run without overwriting other bits while Read_CSR amp 0x2000 wait until spectrum page is transferred to I O buffer Write_TSAR AOUT write the buffer start address Read_Data DMCA LOUT read LOUT 16 bit words into the array DMCA for k 0 k lt LOUT k 2 reconstruct the MCA entry EMCA j 4096 k DMCA 2 k 1 amp OxOOFF 256 DMCA 2 k 54 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved When a sequence of runs is requested the controller overhead can be kept to a minimum in the following way Start the runs with the LAM interrupt enabled bit 4 of the CSR set even if LAMs are not se
27. THEADLEN is 3 but this value should not be hardcoded it should be read from the DSP to ensure upgrade compatibility CHANHEADLEN For each channel that has been read there is a channel header containing energy and auxiliary information ChanHeadLen is the length of this header CHANHEADLEN varies between 2 and 9 words depending on the run type see RUNTASK The event and channel header lengths plus the requested trace lengths determine the maximum logically possible event size The maximum event size 1s the sum of EventHeadLen and the ChannelHeadLengths plus the TraceLengths for all channels marked as good 1 e which have bit 2 in the ChanCSRA set Example With all four channels marked as good and required trace lengths of 1000 i e 25us the maximum event size will be MaxEventSize EventHeadLen 4 ChanHeadLen 1000 4039 In the last line typical values for EventHeadLen 3 and ChanHeadLen 9 were substituted BufHeadLen equals 6 Thus there is room for at least 2 events in the I O buffer which is 8192 words long But there is not enough room in the Level 1 buffer which contains only 2048 words Below follow the addresses and lengths of a number of data buffers used by the DSP program The addresses are generated by the assembler linker when creating the executable On power up the DSP code makes these values accessible to the user Note that the addresses will typically change with every new compilation Therefore your code sho
28. _n1 dll dgf4c iface c dgf4c_igor c vpcic32d h Winaspi h wnaspi32 dll Degf4cWinCustom rc dgf4c_iface h The Igor XOP option also needs the following files in the Igor XOP Library provided by WaveMetrics IgorXOP h VCExtralncludes h Xop h XOPResources h XOPStandardHeaders h XOPSupport h XOPSupportWin h XOPWinMacSupport h XOPSupport x86 lib and IGOR lib 13 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved 3 Control DGF 4C Modules via DGF 4C C Driver 3 1 Initialization DGF 4C modules sitting in a CAMAC crate can be initialized using those functions described in Section 2 As an example we assume two DGF 4C modules one revision D and one revision E module sit in slot 3 and 11 respectively The CAMAC controller sits in slot 24 functioning as a master controller Users are also encouraged to read the sample code shipped with the C Driver 3 1 1 Initialize global variables As discussed in Section 2 we assume that three global variable arrays have been defined Module Global Values Global Data Values and User Values For these three global variable arrays we also need to define three global name arrays Module Global Names Global Data Names and User_Var Names respectively Table 3 1 lists the names contained in each of these name arrays The order of placing these names into the array is not important since the C Driver uses search functions to locate each name at run time Table 3 1 Con
29. are computed as follows PREAMPTAUA floor t PREAMPTAUB 65536 t PreampTauA To recover t use t PREAMPTAUA PREAMPTAUB 65536 This ends the block of channel input data Note that there are four equivalent blocks of input channel data one for each DGF 4C input channel We now show the output variables again beginning with module variables and continuing afterwards with the channel variables The output data block begins at the address 0x4100 Note however that this address could change The output data block comprises of 160 34 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved words 1 block of 32 is reserved for module data 4 blocks of 32 words each hold channel data DECIMATION The DSP reads this value from the trigger filter FPGA It is a characteristic of the configuration that was downloaded You will find that the available configuration files support decimations of 0 1 2 3 4 5 and 6 REALTIMEA REALTIMEB REALTIMEC The 48 bit real time clock A B C are the high middle and low word respectively The clock is zeroed on power up and in response to a synch interrupt when InSynch was set to 0 prior to the run start This requires the Busy Synch loop to be closed see the discussion above RealTime RealTimeA 6553612 RealTimeB 65536 RealTimeC 25ns RUNTIMEA RUNTIMEB RUNTIMEC The 48 bit run time clock A B C words are as for the RealTime clock This time counter is
30. ated and processes the data This in situ code testing allows the most control in the debugging process and is more powerful than having to rely on real signal sources 6 3 Interfacing user code to XIA s DSP code When the DSP is booted it launches a general initialization routine to reach a known and useful state As part of this process a routine called UserBegin is executed It is used to communicate addresses and lengths of buffers local to the user code to the host The host finds this information in the USEROUT 16 buffer described in the main section of this document The calling of UserBegin is not maskable All other functions that are part of the user interface will be called only if bit 0 of MODCSRB is set at the time 43 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved When a run starts the DSP executes a run start initialization during which it will call UserRunInit It may be used to prepare data for the event procesing routines When events are processed by the DSP code it may call user code in two different instances Events are processed one channel at the time For each channel with data UserChannel is called at the end of the processing but before the energy is histogrammed UserChannel has access to the energy the acquired wave form the trace and is permitted one return value This is the routine in which custom pulse shape analysis will be performed After the entire event consisting of data f
31. ay is a quantity that the user will want to set In the DGF 4C Viewer it is called TraceDelay measured in microseconds and is available through the Settings tab The recommended setting for PafLength is PafLength TriggerDelay TraceDelay 0 025 8 Note the constraint PafLength lt 4092 Note that PAFLength should be adjusted only in multiples of 4 as the hardware ignores the lower two bits of this value TRIGGERDELAY This is a partner variable to PafLength For a decimations TriggerDelay PeakSample 6 2 Decimation Note that TriggerDelay should be adjusted only in multiples of 4 as the hardware ignores the lower two bits of this value For MCA runs without taking traces trace length 0 TriggerDelay should be 1 RESETDELAY This variable controls the restarting of the FIFO after it was halted to read the waveform When triggers are distributed across channels and modules a halted FIFO is automatically restarted if the trigger filter FPGA does not receive the distributed event trigger within RESETDELAY 25ns clock ticks after the internal event trigger The default value written by the DGF module should not be changed by the user 31 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved FTPWIDTH The fast trigger pulse which is sent to the multiplicity output has a programmable width set through FTPWidth The pulse width is given in sampling clock periods of 25ns Note the constraint FTPwidth l
32. bits of the read and write bus are ignored 7 2 Initialization Configure first the system FPGA and then the trigger filter FPGAs Then read the ICSR register to confirm that the downloads were successful and set the switchbus bits in the ICSR register to terminate the trigger bus lines Finally download the DSP data to the DSP FPGA configuration files will be found in the DGF4C FirmWare directory These are byte oriented binary files They should be written using block transfer mode one byte at a time The DGF 4C expects to see the data in the lower 8 bits of the CAMAC data way write bus Table 7 1 Boot procedure for revision D and revision E DGFs Action CAMAC command Data Notes Configure Write ICSR F 17 A 8 0x1 System Wait at least 50ms FPGA Write SysFPGA Configuration data Do not read until all F 17 AC0 modules configured Read Read Version F 1 A 13 Result s lower 4 bits hardware contain revision version number D 3 E 4 Configure Write ICSR F 17 A 8 OxFO Trigger Wait at least 50ms Filter Write _FipFPGA Configuration data According to FPGA FU7 AQ revision found above 48 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved Confirm Read_ICSR F 1 A 8 If result 0 all FPGA downloads were Downloads successful Set Write_ICSR F 17 A 8 Switchbus Write CSR F 17 A 0 0x10
33. can be adjusted through the dT variable in the Oscilloscope panel The results are written to the 8192 words long I O buffer Use this function to check if the offset adjustment was successful From the DGF 4C Viewer this function is available through the Oscilloscope Panel Hit the Refresh button to start four consecutive runs with ControlTask 4 in the selected module one for each channel 40 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved ControlTask 5 ControlTask 6 ControlTask 9 ControlTask 10 ProgramFiPPI Write all relevant data to the FiPPI control registers Measure Baselines This routine is used to collect baseline values Currently DSP collects six words BOL BOH BIL B1H time stamp and ADC value for each baseline 1365 baselines are collected until the 8192 word I O buffer is almost completely filled The host computer can then read the I O buffer and calculate the baseline according to the formula B1 B1L B1H 65536 20 MATION BO BOL B0H 65536 202 MATION S TAU PreampTauA PreampTauB 65536 Baseline B1 B0 260 025 SlowLength SlowGap 2 DECIMATION TAU Baseline values can then be statistically analyzed to determine the standard deviation associated with the averaged baseline value and to set the BLCUT BLCUT should be about 3 times the standard deviation Baseline values can also be plotted against time stamp or ADC value to explore the detector performance BLCUT should be
34. d as good will contribute to spectra and list mode data Read always Channels marked as such will contribute to list mode data even if they did not report a hit This is most useful when acquiring induced signal waveforms on spectator electrodes i e electrodes that did not collect any net charge but only saw a transient induced signal Enable trigger Set this bit for channels that are supposed to contribute to an event trigger Trigger positive Set this bit to trigger on a positive slope clear it for triggering on a negative 27 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved Bit 6 Bit 7 Bit 8 Bit 9 Bit 10 Bit 11 Bit 12 15 CHANCSRB Bit 0 Bit 1 slope The trigger filter FPGA can only handle positive signals The DGF handles negative signals by inverting them immediately after entering the FPGA GFLT Set this bit if you want to validate or veto events using the front panel GFLT LEMO input When the bit is cleared the GFLT input is ignored When set the event is accepted only if validated To be validated the GFLT input must be a logic 1 no later than an energy filter rise time after the signal arrival and must remain at logic 1 level until a rise time flat top after signal arrival Histogram energies Set this bit to histogram energies from this channel in the on board MCA memory Reserved Set to 0 Reserved Compute constant fraction timing This pulse s
35. data Secondly when using 6 bit decimation in the FPGA the minimum value for COINCWAIT is larger than 1 in all circumstances Use the following formula to determine COINCWAIT CW ch PEAKSEP ch 2 Decimation ch 0 to 3 OA r 7 CWmax MIN ls 2 Decimation MAX c W ch ch 0 gt 3 25 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved CWmin MAX 0 MIN CWeh ch 0 gt 3 COINCWAIT MAX 1 CW max CW min SYNCHWAIT Controls run start behavior When set to 0 the module simply starts or INSYNCH HOSTIO XdatLength USERIN U00 UNUSEDA resumes a run in response to the corresponding request When set to 1 closing the Busy Synch loop is required For a single module this is accomplished by connecting the Busy output to the Synch input via a Lemo cable If two or more modules are in the system and are to run synchronously a more complex wiring scheme is needed All Busy outputs must lead to the inputs of a multi input OR The result from the OR operation must be fed back to the Synch inputs This kind of set up in connection with Sync Wait 1 will ensure that the last module ready to actually begin data taking will start the run in all modules And the first module to end the run will stop the run in all modules This way it never happens that a multi DGF system is only partially active InSynch is an input output variable It is used in multi DGF systems in which the modules are drive
36. e analysis begins at a point PSAOFFSET sampling clock ticks into the trace and is applied over a piece of the trace with a total length of PSALENGTH clock ticks INTEGRATOR This variable controls the event energy reconstruction BLCUT 0 Normal code 1 Use energy filter gap sum only This is useful for scintillator applications where event energies can be derived by setting the energy filter flat top long enough to cover the whole scintillation pulses 2 Ignore energy filter gap sum when reconstructing event energy This is useful for step pulses whose amplitude is the difference between the high and low steps This variable sets the cutoff value for baselines in baseline measurements If BLCUT is not set to zero the DSP checks continuously each baseline value to see if it is outside of the limit set by BLCUT If the baseline value is within the limit it will be used to calculate the average baseline value Otherwise it will be discarded Set BLCUT to zero to not check baselines therefore reduce processing time ControlTask 6 can be used to measure baselines The host computer can then histogram these baseline values and determine the appropriate value for BLCUT for each channel according to the standard deviation SIGMA for the averaged baseline value BLCUT could be set to be three times SIGMA 33 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved CFDREG Reserved for FPGA based constant fraction discriminat
37. ented detector the ADC offset would be 2048 units 1 e midway between 0 and 4095 Note that for both revision D and revision E modules ADC waveforms are reported as 14 bit numbers ranging from 0 to 16383 Hence the DC offsets should be adjusted to produce readings of 1600 and 8192 counts respectively for unipolar and bipolar signals A user program would use the result from the calibration task to find set and program the correct offset DAC values Since the offset measurement has to take the preamplifier offset into account this measurement must be made with the preamplifier connected to the DGF 4C input The control task makes 16 measurements at each DAC step and uses the last computed DC offset value to enter into the I O buffer Due to electronic noise it may occasionally happen that none of the sixteen attempts at a base line measurement is successful in which case a zero is returned The user software must be able to cope with an occasional deviation from the expected straight line On exit the task restores the offset DAC values to the values they had on entry Untriggered Traces This task provides ADC values measured on all four channels and gives the user an idea of what the noise and the DC levels in the system are This function samples 8192 ADC words for the channel specified in HOSTIO The XWAIT variable determines the time between successive ADC samples samples are XWAIT 25ns apart In the DGF 4C Viewer XWAIT
38. esults including time of arrival energy XIA pulse shape analysis user pulse shape analysis GSLTtimeA GSLTtimeB GSLTtimeC etc are written into the I O buffer for each channel However values of XIA pulse shape analysis and user pulse shape analysis are meaningless due to no trace capture RunTask 513 0x201 requests a compressed fast list mode run without trace capture Both Level 1 buffer and 1 O buffer are used in this RunTask Nine words of results including time of arrival energy XIA pulse shape analysis user pulse shape analysis GSLTtimeA GSLTtimeB GSLTtimeC etc are written into the I O buffer for each channel However values of XIA pulse shape analysis and user pulse shape analysis are meaningless due to no trace capture RunTask 514 0x202 requests a compressed fast list mode run The only difference between RunTask 514 and 513 is that in RunTask 514 only four words of results time of arrival energy XIA pulse shape analysis user pulse shape analysis are written into the 1 O buffer for each channel However values of XIA pulse shape analysis and user pulse shape analysis are meaningless due to no trace capture RunTask 515 0x203 requests a compressed fast list mode run The only difference between RunTask 515 and 513 is that in RunTask 515 only two words of results time of arrival and energy are written into the I O buffer for each channel RunTask 769 0x301 requests a MCA run The raw data stream is alway
39. f the DGF 4C Viewer MINWIDTH This value aids the pile up inspector MinWidth is the minimum duration in sample clock ticks 25ns which the output from the fast filter must spend over threshold Pulses shorter than that will be rejected as noise spikes The recommended setting is MinWidth FastLength FastGap MAXWIDTH This value aids the pile up inspector MaxWidth is the maximum duration in sample clock ticks 25ns which the output from the fast filter may spend over threshold Pulses longer than that will be rejected as piled up The recommended setting is Max Width FastLength FastGap SignalRiseTime 25ns Note the constraint MaxWidth lt 256 Setting Maxwidth 0 switches this part of the pile up inspector off Indeed it is recommended to begin with MaxWidth 0 Once the other parameters have been optimized one can use the MaxWidth cut to improve the pile up rejection at high count rates Maxwidth should be tuned by observing the main energy peak in the spectrum for fixed time intervals Once the MaxWidth cut is too tight there will be a loss of efficiency in the main peak Setting MaxWidth to such a value that the efficiency loss in the main peak is acceptable will give the best overall performance in terms of efficiency and pile up rejection PEAKSAMPLE This variable determines at what time the value from the energy filter will be sampled Note that the following formulae depend on the decimation 0 bit decimation PeakSamp
40. hape analysis computes the time of arrival for the signal from the recorded waveform The result is stated in units of 1 256 of a sampling period 25ns Time zero is the start of the waveform Enable contribution to multiplicity Any of the four channels can contribute to the multiplicity output at the front panel With this bit one can switch this contribution on or off Reserved Control and status register B If set call user written DSP code If set all words in the channel header except Ndata trigtime and energy will be overwritten with the contents of URETVAL Depending on the run type this allows for 6 2 or 0 user return values in the channel header Bit2 15 are reserved Set to 0 The following two data words are used to set the on board DACs for this channel Once a new variable has been written to DSP memory the DACs have to be reprogrammed by starting a run with RunTask 0 and ControlTask 0 28 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved GAINDAC This DAC is used to program the variable gain amplifier The GainDAC value corresponds to a gain according to the following formula Gain V V 0 1639 104 65535 GAINDAC 32768 TRACKDAC This DAC determines the DC offset voltage The offset can be calculated using the following formula Offset V 3 0 32768 TRACKDAC 32768 U02 Begin of a reserved data block The following block of data contains trigger filter FPGA data
41. he host into the internal memory This is useful for diagnosing DGF modules by looking at their internal memory values The other usage of this function is to read save copy or extract DGF s configurations though its settings files In a multi module DGF system it is essential for the host to know which module and which channel it is communicating to The function C_Dgf4c_Set_Current_ModChan is used to set the current module and channel The detailed description of each function is given below 2 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved C_Dgf4c_Hand_Down_Names Syntax long C Dgf4c Hand Down Names char Names An array containing the names to be downloaded char Name A string indicating the type of names file or variable names to be downloaded Description Use this function to download file or variable names from host user interface to the DGF 4C C driver The driver needs these file names so that it can read the DGF hardware configurations from the files stored in the host computer and download these configurations to the DGF The variable names are used by the driver to obtain the indices of DSP variables when the driver converts user variable values into DSP variable values or vice versa Parameter description Names is a two dimensional string array containing either the file names or the variable names It can be one of the following four sets of names whose selection depends
42. hts reserved Note that since software revision 2 60 the RUNTASK variable determines which buffer is the intermediate buffer in a run Bit 1 9 Reserved Set to 0 Bit 10 13 Bitmask for switchbus settings for revision D and revision E DGF 4Cs only These bits are stored in DSP memory but have to be written to the ICSR register by the host computer to set the FET switches for proper trigger line termination Refer to Table 9 7 in Section 9 3 of the DGF User s Manual for application details To terminate the fast trigger bus line with 100 Q set bit 10 of the ICSR To terminate the event trigger dsp trigger bus line with 100 Q set bit 13 of the ICSR Bit 11 12 Reserved Bit 14 15 Reserved MODCSRB Module Control and Status Register B This is a bit oriented variable Bit 0 If set user written DSP code is called Bit 1 15 Reserved Set to 0 MODFORMAT List mode data format descriptor Currently it is not in use SUMDAC The value of this variable controls the SUMDAC digital to analog converter It can be used to set a trigger threshold on either the multiplicity or the sum analog signal from any combination of the four input channels See the user s manual for the required jumper settings The threshold in volt can be calculated as follows Threshold 32768 SUMDAC 32768 3 0V RUNTASK This variable tells the DGF what kind of run to start in response to a run start request Nine run tasks are currently suppor
43. initialize the global variable array Module Global Values After that function C_Dgf4c Hand Down Names should be called again to download the file name array All Files Finally function C_Dgf4c_ Boot System should be called to boot the modules The following code is an example showing how to boot the DGF 4C modules using the C Driver functions 15 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved Table 3 4 An Example Code Illustrating How to Boot DGF 4C Modules download module global names C_Dgf4c Hand _Down_Names Module Global_Names MODULE GLOBAL NAMES download global data names C_Dgf4c Hand _Down_Names Global_Data_Names GLOBAL DATA NAMES download user variable names C_Dgf4c Hand _Down_Names User_Var_Names USER_VAR_NAMES initialize module global values C_Dgf4c User Par IO Module Global Values MODULE GLOBAL VALUES 0 download file names C_Dgf4c Hand Down _Names All Files ALL FILES boot DGF 4C modules C_Dgf4c Boot _System 0x1F set current module and channel number C_Dgf4c_Set_Current_ModChan 1 0 3 2 Setting DSP variables The host computer communicates with the DSP by setting and reading a set of variables called DSP I O variables These variables totally 416 unsigned 16 bit integers sit in the first 416 words of the data memory The first 256 words which store input variables are both readable and writeable whi
44. ins in a 2 column format the offset and name of every user accessible variable We suggest that user code use this information to create a name gt address lookup table rather than relying on the parameters retaining their address offsets with respect to the start address The input parameter block is partitioned into 5 subunits The first contains 64 data that pertain to the DGF 4C as a whole It is followed by four blocks of 48 words which describe the settings of the four channels Below we describe the module and channel parameters in turn Where appropriate we show how a variable can be viewed using the DGF 4C Viewer The DGF 4C C Driver function used to write or read these parameters is C_Dgf4c User Par IO and the corresponding DSP parameters to the user defined global variables are listed in Table 3 6 4 1 Module parameters MODNUM Logical number of the module This number will be written into the header of the I O buffer to aid offline event reconstruction MODCSRA Module Control and Status Register A The viewer panel is the Module CSRA Edit Panel This is a bit oriented variable Bit 0 Write data to the circular Level 1 buffer In this mode data are first being written into a 2048 word deep buffer Results but not traces are written to the linear I O buffer This mode is useful when only the results from pulse shape analyses but not the traces are requested 21 DGF 4C Programmer s Manual V3 04 XIA 2004 All rig
45. is shown by the DGF4C Viewer as the threshold value in the Settings tab 38 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved 5 Control Tasks The DSP can execute a number of control tasks which are necessary to control hardware blocks that are not directly accessible from the host computer The most prominent tasks are those to set the DACs program the trigger filter FPGAs and read the histogram memory The following is a list of control tasks that will be of interest to the programmer To start a control task set RUNTASK 0 and choose a CONTROLTASK value from the list below Then start a run by setting bit 0 in the control and status register CSR Control tasks respond within a few hundred nanoseconds by setting the RUNACTIVE bit 13 in the CSR The host can poll the CSR and watch for the RUNACTIVE bit to be deasserted All control tasks indicate task completion by clearing this bit Execution times vary considerably from task to task ranging from under a microsecond to 10 seconds Hence polling the CSR is the most effective way to check for completion of a control task Control Task 0 SetDACs Write the gaindac and trackdac values of all channels into the respective DACs Also program the SumDAC Reprogramming the DACs is required to make effective changes in the values of the variables GAINDAC 0 3 TRACKDAC 0 3 and SUMDAC Control Task 1 Connect inputs Close the input relay to connect the DGF electro
46. l 1 buffer and the output data buffer will be cleared The ResumeRun initiation consequently is much faster a few microseconds as compared to about 50ms for NewRun For clarity the code below shows how to interact with a single module but is easily expanded to deal with an arbitrary number of modules Table 7 6 Using the word count register in a sequence of list mode data runs Reading the word count register clears that register clears any LAM request by this module and advances the TSAR to the second word of the output buffer for Nrun 0 Nrun lt MaxRun Nrun main loop MaxRun runs cmd Read_CSR read CSR cmd setbit 0 cmd set bit 0 in cmd for run start request If Nrun 0 cmd setbit 1 cmd set bit 1 in cmd for NewRun Else cmd clrbit 0 cmd clear bit 1 incmd for ResumeRun Endif Write_CSR cmd write back cmd without corrupting other bits while Read_CSR amp 0x4000 wait for run to end poll LAMstate bit of CSR NumData Read_WrdCnt get the number of data available Bufdat 0 NumData NumData is also the first word of output data Read _Data bufdat 1 NumData 1 read remaining NumData 1 data words and store in bufdat array 55 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved
47. le max 0 SlowLength Slow Gap 7 1 bit decimation PeakSample max 2 SlowLength Slow Gap 4 2 bit decimation PeakSample SlowLength Slow Gap 2 3 bit and higher decimation PeakSample SlowLength Slow Gap 1 If the sampling point is chosen poorly the resulting spectrum will show energy resolutions of 10 and wider rather than the expected fraction of a percent For some parameter combinations PeakSample needs to be varied by 30 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved PEAKSEP one or two units in either direction due to the pipelined architecture of the trigger filter FPGA This value governs the minimum time separation between two pulses Two pulses that arrive within a time span shorter than determined by PeakSep will be rejected as piled up The recommended value is PeakSep PeakSample 5 If PeakSep gt 33 PeakSep PeakSample 1 Note the constraint 0 lt PeakSep PeakSample lt 7 PAFLENGTH A FIFO control variable that needs to be written into the trigger filter FPGA Using the programmable almost full register we can time the waveform capturing thus that by the time the DSP is triggered at the end of the pile up inspection period the data of interest have percolated through to the begin of the FIFO and are available for read out without delay The acquired waveform will start rising from the baseline at a time delay after the beginning of the trace This del
48. le the remaining 160 words which store pointers to various data buffers and run summary data are only readable The exact location of any particular variable in the DSP code will vary from one code version to another To facilitate writing robust user code we provide a reference table of variable names and addresses with each DSP code version Included with your software distribution is a file called DGFcodeE var It contains a two column list of variable names and their respective addresses Thus you can write your code such that it addresses the DSP variables by name rather than by fixed location It should come as no surprise that many of the DSP variables have meaningful values and ranges depending on the values of other variables A complete description of all interdependencies can be found in Section 4 All of these interdependencies have been taken care of by the DGF 4C C Driver So instead of directly setting DSP variables users only need to set the values of those global variables defined in Table 3 1 The C Driver will then convert these values into corresponding DSP variable values and download them into the DSP data memory On the other hand if users want to read out the data memory the C Driver will first convert these DSP values into the global variable values The code shown in Table 3 5 is an example of setting DSP variables through the C Driver Table 3 6 gives a complete description of all the global variables being used by the DGF
49. m 18 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved memory is accessible after a MCA run or a list mode run if histogramming energy is requested The following code in Table 3 7 is an example of how to start a MCA run and read out the MCA spectrum after the run is finished Table 3 7 Accessing the spectrum memory start a MCA run dummy is an unsigned 32 bit integer array of any size C_Dgf4c_Acquire_Data 0x1301 dummy gt wait until run has ended while C_Dgf4c_Acquire Data 0x4301 dummy stop run and save MCA spectrum to a file C_Dgf4c_Acquire_Data 0x3301 dummy file_name read out the MCA spectrum and put it to array User_data C_Dgf4c_Acquire Data 0x7301 User_data gt 3 3 2 Access list mode data In a list mode run setup you can do any number of runs in a row The first run would be started as a NEW run This clears all histograms in memory Once the I O buffer is full and has been read out you can RESUME running This keeps the histogram memory intact and you can accumulate spectra over many runs The example code shown in Table 3 8 illustrates this Table 3 8 Command sequence for multiple list mode runs in a row C_Dgf4c_ Acquire Data 0x1100 dummy start a new list mode run k 1 initialize counter do while C_Dgf4c_ Acquire _Data 0x4100 dummy wait until run has ended C_Dgf4c_Acquire_ Data 0x610
50. n by a common clock When InSynch is 1 the module assumes it is in synch with the other modules and no particular action is taken at run start If this variable is 0 then all system timers are cleared at the beginning of the next data acquisition run RunTask gt 0 Using the Busy Synch loop as described above the timers are reset when the entire system actually starts the run After run start InSynch is automatically set to 1 Clock resetting can occur only if the Busy Synch loop is closed A 4 word data block that is used to specify command options Currently it is only used to specify the channel in an external memory transfer specify the channel when reading untriggered traces specify the channel for baseline measurements Length of a data block to be downloaded from the host Use XdatLength 0 as the default value for normal operation A block of 16 input variables used by user written DSP code Many unused but reserved data blocks have names of the structure Unn Those unused data blocks which reside in the block of input parameters for each channel are called UNUSEDA and UNUSEDB Only used in Controltask 4 for reading untriggered traces UNUSEDA stores the weight in the geometric weight averaging scheme to remove higher frequency signal and noise components The value is calculated as follows For a given dt in us calculate the integer intdt dt 0 025 26 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights
51. nd linker distributed by Analog Devices Both versions are in use at XIA and work fine It may be inconvenient but is unavoidable to program the ADSP 2181 on board processor in assembler rather than in a higher level programming language like C We found that code generated by the C compiler is bloated and consequently runs very slow As the main piece of the code could not be written in C at all we did not burden our design by trying to be compatible with the C compiler Hence using the C compiler is currently not an option With the general software distribution we provide working executables and support files To support user DSP programming we provide files containing pre assembled forms of XIA s DSP code together with a source code file that has templates for the user functions The user templates have to be converted by the assembler and the whole project is brought together by the linker XIA provides a link and a make file to assist the process In the DGF 4C Viewer we provide powerful diagnostic tools to aid code developing and a data interface to exchange data between the host and the user code The DGF 4C Viewer can at any time examine the complete memory content of the DSP and call any variable from any code section by name A particularly useful added feature is the capability to download data in native format into the DSP and pretend that they were just acquired The event processing routine which calls the user code is then activ
52. nics to the input connector Control Task 2 Disconnect inputs Open the input relay to disconnect the DGF electronics from the input connector Control Task 3 Ramp offset DAC This is used for calibrating the offset DAC For each channel the offset DAC is incremented in 2048 equal size steps At each DAC setting the DC offset is determined and written into the I O buffer At the end of the task the I O buffer holds the following data Its 8192 words are divided up equally amongst the four channels Data for channel 0 occupy the lowest 2048 words followed by data for channel 1 etc The first entry for each channel s data block is for a DAC value of O the last entry is for a DAC value of 65504 In between entries the DAC value is incremented in steps of 32 An examination of the results will reveal a linearly rising or falling response of the ADC to the DAC increments The slope depends on 39 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved ControlTask 4 the trigger polarity setting 1 e bit 5 ofthe channel control and status register A ChanCSRA For very low and very big DAC values the ADC will be driven out of range and an unpredictable but constant response is seen From the sloped parts a user program can find the DAC value that is necessary for a desired ADC offset It is recommended that for unipolar signals an ADC offset of 400 units is chosen For bipolar signals like the induced waveforms from a segm
53. o be initialized This is a process in which the names of system configuration files and variable names are downloaded to the driver The function C_Dgf4c_Hand_Down_Names is used to achieve this The second step is to boot the DGF modules It involves downloading all FPGA configurations and booting the digital signal processor DSP It concludes with downloading all DSP parameters the instrument settings and commanding the DSP to program the FPGAs and the on board digital to analog converters DAC All this has been encapsulated in a single function C_Dgf4c_Boot_System Now the instrument is ready for data acquisition The function used for this purpose is C_Dgf4c_ Acquire Data By setting different run types it can be used to start end or poll a data acquisition run list mode run MCA run or special task runs like acquiring ADC traces It can also be used to retrieve list mode or histogram data from the DGF modules 1 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved After checking the quality of a MCA spectrum a DGF user may decide to change one or more settings like energy filter rise time or flat top The function used to change DGF settings is C_Dgf4c User Par IO This function converts a user parameter like energy filter rise time in us into a number understood by the DGF hardware or vice versa Another function C_Dgf4c_Buffer_IO is used to read data from DSP s internal memory to the host or write data from t
54. onding DSP Legal Range of Variables Variable Values MODULE NUMBER Read only N A MODNUM 1 Max of Modules MODULE CSRA Read Write N A MODCSRA N A MODULE CSRB Read Write N A MODCSRB N A MODULE FORMAT Read Write N A MODFORMAT N A MAX EVENTS Read Write N A MAXEVENTS N A COINCIDENCE PATTERN Read Write N A COINCPATTERN 0 65535 ACTUAL COINCIDENCE WAIT Read Write N A COINCWAIT N A MIN COINCIDENCE WAIT Read only NA COINCWAIT N A SYNCH WAIT Read Write N A SYNCHWAIT Oorl IN_SYNCH Read Write N A INSYNCH Oorl RUN_TYPE Write only N A RUNTASK 0x100 0x301 BUFFER HEAD LENGTH Read only N A BUFHEADLEN 6 EVENT HEAD LENGTH Read only N A EVENTHEADLEN 3 CHANNEL HEAD LENGTH Read only N A CHANHEADLEN 9 4 2 OUTPUT BUFFER LENGTH Read only N A LOUTBUFFER 8192 NUMBER_EVENTS Read only N A NUMEVENTSA N A NUMEVENTSB RUN_TIME Read only s RUNTIMEA N A RUNTIMEB RUNTIMEC 17 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved DECIMATION Read only NA DECIMATION 1 2 3 4 5 6 User_Var_Names I O Type Unit Corresponding Legal Range of DSP Variables Variable Values CHANNEL CSRA Read Write NA CHANCSRA N A CHANNEL CSRB Read Write NA CHANCSRB N A ENERGY RISETIME Read Write us SLOWLENGTH Depends on decimation ENERGY FLATTOP Read Write us SLOWGAP Depend
55. onocccinccincccnoncconncconaconn cono nonn coco nocnnns 18 3 3 1 Access PECUARIA R R 18 3 3 2 Access list mode A A a 19 User Accessible Variables ista a 21 A T A Maio e a E a R EA 21 4 2 Channel vanables cenian ee a a e A omens E EE 27 43 A o a 38 Control Task dada 39 Appendix A User supplied DSP code siciliana 43 6 1 sd nsn Gata ia Seiad le tia S a Genel ls ae cells ERE 43 6 2 The development environment ccceecceessecsseceseceeeeceeeeeeseecsaeceseeeeeeeeseecsseenseenees 43 6 3 Interfacing User code to XIA s DSP COE imitan lisas liada 43 6 4 Theinterface sron e e A E aan iit alata thine E cca eins vas celal 44 O DIT neiseina e chance a a a aaa aa 47 Appendix B Control DGF 4C modules using CAMAC commands eee 48 Tale SCAMAC IEA A A a ada 48 Tide cs A AI 48 Tas LLAMA EM a o do 50 7 4 Using level 1 fast CAMAC data reads oocooconccciocccoonoconanonnnonnncnnncconocnnn cono ncon caco nacnnos 51 To Accessing DSP Val lables at Aid 51 7 6 Data acquisition runs and data buffering lia 51 11 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved 1 Overview This manual is divided into three major sections The first section is a description of the DGF 4C C Driver which is currently used in the DGF 4C Viewer Advanced users can build their own user interface using the user accessible functions in the driver The second section is a reference guide to program the DGF 4C modules via the C Driver This
56. or LOG2BWEIGHT The DGF measures baselines continuously and effectively extracts DC offsets from these measurements The DC offset value is needed to apply a correction to the computed energies To reduce the noise contribution from this correction baseline samples are averaged in a geometric weight scheme The averaging depends on Log2Bweight DC_avg DC DC_avg DC 22LOG2BWEIGHT DC is the latest measurement and DC_avg is the average that is continuously being updated At the beginning and at the resuming of a run DC_avg is seeded with the first available DC measurement As before the DSP ensures that LOG2BWEIGHT will be negative The noise contribution from the DC offset correction falls with increased averaging The standard deviation of DC_avg falls in proportion to sqrt 2 LOG2BWEIGHT When using a BLCUT value from a noise measurement the DGF will internally adjust the effective Log2Bweight for best energy resolution up to the maximum value given by LOG2BWEIGHT Hence the Log2B weight setting should be chosen at low count rates dead time lt 10 Best energy resolutions are typically obtained at values of 3 to 4 and this parameter does not need to be adjusted afterwards U04 Begin of an unused data block PREAMPTAUA High word of the preamplifier exponential decay time PREAMPTAUB Low word of the above The two variables are used to store the preamplifier decay time The time Tt is measured in us The two words
57. ord middle low word GSLTtimeB of the 40MHz timer GSLTtimeC GSLT arrival time RUNTASK RUNTASK of the current run EOL lagging Energy filter low word E0H lagging Energy filter high word EIL leading Energy filter low word ElH leading Energy filter high word Y our return value is UretVal It is an array of 6 words If bit 1 of ChanCSRB is 0 only the first word is incorporated into the output data stream by the main code See Tables 4 2 to 4 6 in the user manual for the output data structure If the bit is 1 up to six values are incorporated overwriting the XIA PSA value the USER PSA value the GSLT time and the 45 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved reserved word in the channel header If the run type compresses the standard nine channel header words the number of user return values is reduced accordingly 1 e only 2 words are avallable in RunTask 0x102 or 0x202 and no words in RunTask 0x103 or 0x203 When entering UserChannel or UserEvent the address register I5 will point to the start of the current event Register usage The user routines may use all computational registers without having to restore them However the secondary register set cannot be used because the XIA interrupt routines use these The usage of the address registers I0 I7 and the associate registers M0 M7 and LO L7 is subject to restrictions These are listed below for the various routines The associate registers L
58. ou stopped any run in progress Assuming that the 256 DSP variable values are stored in an array called DSPvalues the sequence of operations in pseudocode using the CAMAC commands defined above is given in Table 7 3 7 6 Data acquisition runs and data buffering When the DSP receives an event interrupt it responds by gathering the requested data from the RTPUs We minimize the dead time associated with the interrupt routine by writing the intermediate data to a buffer and deferring the event related computations Those are performed by an event processing routine which is executed in regular not interrupt mode A global write and a global read pointer control writing to and reading from the data buffer The interrupt routine updates the write pointer while the event processing routine increments the read pointer The read pointer is incremented to point to the next event only after the event computations are finished You can do any number of list mode runs in a row The first run would be started with bit 1 of the interface CSR set to 1 This clears all histograms in memory Subsequent runs would complete when the linear data buffer is full Once it has been read out you resume running with bit 1 of the interface CSR set to 0 This keeps the histogram memory intact and you can accumulate spectra over many runs The pseudocode in Table 7 4 illustrates this 51 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved Table 7 3
59. ported by the driver NOTE when polling the status of a data acquisition run Run_Type 0x4000 the return value of C_Dgf4c_Acquire_Data will depend on the run type Data run list mode or MCA run 0 runis still in progress 1 runhas finished Control task runs O runhas finished 1 runis still in progress Usage example start a new list mode run C_Dgf4c Acquire Data 0x1100 dummy wait until the run has ended while C_Dgf4c Acquire Data 0x4100 dummy stop run and save list mode run data C_Dgf4c Acquire Data 0x6100 dummy file name 1 store energy histogram C Dgf4c Acquire Data 0x3100 dummy file name 2 9 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved C_Dgf4c_Set_Current_ModChan Syntax long C_Dgf4c Set Current ModChan unsigned short Module Module number to be set unsigned short Channel Channel number to be set Description Use this function to set the current module number and channel number Parameter description Module is an unsigned 16 bit integer which specifies the current module to be set Module should be in the range of to 23 Channel is an unsigned 16 bit integer which specifies the current channel to be set Channel should be in the range of 0 to 3 Return values Value Description Error Handling 0 Success None lt 0 Failed to set module or channel number Check the error message reported by
60. r example to set termination for both fast and DSP triggers issue F 17 A 8 0x2400 The lower 8 bits should be always zero Booting the DSP is done similarly to configuring the FPGAs A write to the interface control and status register halts the DSP Then one downloads the DSP code except for the first word which has to be written last When it is written the DSP starts running The DSP code is stored in a binary file as a sequence of 32 bit numbers The file to be used for booting the DSP is DGFcodeE bin Table 7 1 assumes that the code is stored in an integer 16 array called DSPcode 0 N in which the high word of each 32 bit program instruction is stored at even 49 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved numbered indices On file the 32 bit words are stored in PC native format i e least significant byte first 7 3 CAMAC commands Below follows a list of CAMAC commands to be used by programmers This list is not exhaustive The modules also respond to other commands not listed here Those commands however are for XIA use only Therefore you must make sure that the modules are not addressed with commands other than those shown in Table 7 2 Accessing DSP memory is a two step process First you have to write the start address for the data transfer into TSAR Then you begin a block transfer The data transfer between the interface FPGA and the DSP is via a DMA channel and does not interrupt the running DS
61. rection read or write Description Use this function to transfer user parameters between the user interface driver and DSP s I O memory Some of these parameters are applicable to all DGF modules in the system like CAMAC Controller ID or SCSI Bus number Other parameters are applicable to either a DGF module independent of its four channels e g coincidence pattern or any of the four channels in a DGF module e g energy filter settings For those parameters which need to be transferred to or from DSP s internal memory other parameters such as number of modules are only used by the driver this function calls another function UA_PAR_IO which first converts these parameters into numbers that are recognized by both the DSP and the driver then performs the transfer Parameter description User_Par Values is a double precision array containing the parameters to be transferred Depending on another input parameter User_Par_Name different User_Par Values array should be used Totally three User_Par Values arrays should be defined and all of them are one dimensional arrays The corresponding relationship between User Par Values and User_Par_ Name is listed in Table 2 1 Table 2 1 The Combination of User_ Par _ Name and User _ Par Values User Par Values Name Size Data Type MODULE GLOBAL NAMES Module Global Values 64 Double precision GLOBAL DATA NAMES SYNCH_WAIT or IN_SYNCH Element of array User_Var_Names User_Values 64x24x4
62. reserved Then if intdt gt 11 XWAIT 4 floor intdt 3 4 3 Finally UNUSEDA floor 65536 intdt 3 4 If intdt lt 11 UNUSEDA is ignored 4 2 Channel variables All channel 0 variables end with 0 channel 1 variables end with 1 etc In the following explanations the numerical suffix has been removed Thus e g CHANCSRAO becomes CHANCSRA etc CHANCSRA The control and status register bits switch on off various aspects of the Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 DGF 4C operation see the Channel CSRA Edit Panel reachable through the Settings tab of the DGF 4C Viewer In general setting the bit activates the option in question Respond to group triggers only Set this bit if you want to control the waveform acquisition for non triggering channels by a triggering master channel For this option to work properly choose one channel as the master and have its Trigger Enable bit set All dependent channels should have their Trigger_Enable bit cleared Set bit 0 in all slave channels You should also set it in the master channel to ensure equal time of arrivals for the fast trigger signal which is used to halt the FIFOs Measure individual live time Keep this bit cleared when operating with master and slave channels or when making coincidence measurements using single modules Set this bit when measuring independent spectra i e when list mode data are not required Good channel Only channels marke
63. rom one to four channels has been processed the function UserEvent may be called It may be used in applications in which data have to be correlated across channels At the end of a run the closing routine may call UserRunFinish typically for updating statistics and similar run end tasks The above mentioned routines are described below including the interface variables and the permissible use of resources 6 4 The interface The interface consists of five routines and a number of global variables Data exchange with the host computer is achieved via two data arrays that are part of the I O parameter blocks visible to the host The total amount of memory available to the user comprises 2048 instructions and 1000 data words Host interface as supported by the DGF4C Viewer UserIn 16 16 words of input data UserOut 16 16 words of output data Interface DSP routines UserBegin This routine is called after rebooting the DSP Its purpose is to establish values for variables that need to be known before the first run may start Address pointers to data buffers established by the user are an example The host will need know where to write essential data to before starting a run Since the DSP program comes up in a default state after rebooting UserBegin will always be called This is different for the routines listed below which will only be called if for at least one channel bit 0 of ChannelCSRB has been set 44 DGF 4C Programmer
64. rviced by the controller At the end of each run the DSP writes the buffer start address into its own DMA address register sets the LAMstate bit bit 14 of the CSR and writes the number of data words NumData available into the word count register of the CAMAC interface NumData is also stored in the first word of the output buffer To see if the run is finished the user code should poll the modules and check if the LAMstate bit is set If so reading the word count register tells the number of words available and clears the register it can t be read twice The read also clears the LAMstate bit and advances the TSAR to the second word of the output buffer A data read can follow immediately without having to write the TSAR keeping in mind that since the TSAR was advanced only ndat 1 words should be read This mechanism allows the DSP to dynamically shift memory allocations during or in between runs without having to notify the host computer The following piece of pseudocode illustrates this It shows how to start and stop runs from the host and read the data The first run in a sequence will be of type NewRun meaning that all histograms are cleared and a complete run initiation is performed prior to starting This ensures that all parameter changes that were made in between runs will go into effect The following runs will be of the ResumeRun type in which all previous data are kept and histograms will not be cleared Only the leve
65. s sent to the Level 1 buffer independent of MODCSRA The data gathering interrupt routine fills that buffer with raw data while the event processing routine removes events after processing If the interrupt routine finds the Level 1 buffer to be full it will ignore events until there is room again in the buffer The run will not abort due to buffer full condition This run type does not write data to the I O buffer The module variable MAXEVENTS should be set to zero to avoid early run termination due to a MAXEVENTS exceeded condition The RunTask can be chosen as the run type in the Run tab of the DGF 4C Viewer CONTROLTASK Use this variable to select a control task Consult the control tasks section of this manual for detailed information The control task will be launched when you issue a run start command with RUNTASK 0 24 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved MAXEVENTS The module ends its run when this number of events has been acquired In the DGF 4C Viewer MAXEVENTS is automatically calculated when a run mode is chosen from the run type pulldown menu The calculation is based on the trace lengths set by the user Set MaxEvents 0 if you want to switch off this feature e g when logging spectra done automatically in an MCA mode run COINCPATTERN In the DGF 4C Viewer the user can request that certain coincidence anticoincidence patterns are found for the event to be accepted With four channels
66. s Write DSP I O vaneble values to modules 1 Read DSP I O variable values from modules 1 0 Values to be written Write to certain locations of the data memory 1 All DSP variable values Read all DSP variable values from modules 0 Save current settings in all modules to a file 2 1 N A Read settings from a file and apply to all modules 0 Values 0 source module Extract settings from a file and apply to number Values 1 source selected modules 3 channel number Values 2 i copy extract pattern bit mask Copy settings from a source module to Values 3 Values 4 destination modules destination channel pattern xs Values 0 address Values 1 Specify the location and number of words to be 4 N A length written into the data memory 11 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved Special care should be taken for this I O operation since mistakenly writing to some locations of the data memory will cause the system to crash The Type 4 I O operation should be called first to specify the location and the number of words to be written before calling this one If necessary please contact XIA for assistance Any unsigned 16 bit integer array could be used here Direction can be either 0 or 1 and it has no effect on the operation Return values Value Description Error Handling 0 Success None lt 0 I O operation failed Check the error message reported by the driver
67. s on decimation TRIGGER RISETIME Read Write us FASTLENGTH 0 025 0 775 TRIGGER FLATTOP Read Write us FASTGAP 0 0 75 TRIGGER_THRESHOLD Read Write N A FASTTHRESH 0 4095 FASTLENGTH VGAIN Read Write V V GAINDAC 0 16 VOFFSET Read Write V TRACKDAC 3 3 TRACE LENGTH Read Write us TRACELENGTH 0 100 TRACE DELAY Read Write us TRIGGERDELAY 0 100 PSA START Read Write us PSAOFFSET 0 100 PSA END Read Write us PSALENGTH 0 100 EMIN Read Write N A ENERGYLOW 0 32768 BINFACTOR Read Write NA LOG2EBIN 1 2 3 4 5 6 TAU Read Write us PREAMPTAUA N A PREAMPTAUB BLCUT Read Write N A BLCUT N A XDT Read Write us XWAIT gt 0 075 BASELINE PERCENT Read Write BASELINEPERCENT 0 100 CFD THRESHOLD Read Write CFDTHR 0 100 MULTIPLICITY PULSE WIDTH Read Write 25 ns FTPWIDTH 1 65535 LIVE_TIME Read only s LIVETIMEA N A LIVETIMEB LIVETIMEC INPUT_COUNT_RATE Read only cps FASTPEAKSA N A FASTPEAKSB FASTPEAKSC LIVETIMEA LIVETIMEB LIVETIMEC 3 3 Access spectrum memory or list mode data 3 3 1 Access spectrum memory The MCA spectrum memory is fixed to 32K words 24 bits per word per channel residing in the external memory The memory is organized into 8 pages of 4K words To read out the spectra to the host each page has first to be transferred from the external memory to the linear I O buffer in the DSP memory and then read out by a DMA transfer The Spectru
68. set to zero while running ControlTask 6 Read histogram memory 1 page Transfers the first page of external memory into the DSP s data memory The target location in the DSP memory is the main I O buffer beginning at the address contained in AOUTBUFFER The external memory is organized on a channel by channel basis and HOSTIO specifies which channel to transfer This routine is used to read out spectra after a run During a data run each channel fills a 32K spectrum 24 bits deep in the external memory The external memory is organized into 8 pages of 4K words In the control run one 4K x 24 bits page is written into the 8K x 16 bits I O buffer After the control run is finished the host has to read out the I O buffer ControlTask 9 always transfers the first page of a given channel then increments a page counter For subsequent transfers of the remaining 7 pages use ControlTask 10 Read histogram memory subsequent pages Transfers a page of external memory into the DSP s main I O buffer An internal page counter specifies the page It is set to zero first page in a ControlTaks 9 and is incremented by the DSP after each ControlTasks 9 or 10 To read out all 8 pages of a channels spectrum first start a run with ControlTask 9 followed by seven runs with 41 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved ControlTask 11 ControlTask 12 ControlTask 13 19 ControlTask 20 ControlTask 21
69. sk 0x4 reading out list mode data or MCA spectrum In all other cases User_data can be any unsigned integer array with arbitrary size Make sure that User_data has the correct size and data type before reading out ADC traces list mode data or MCA spectrum Parameter description Run_Type is a 16 bit word whose lower 12 bit specifies the type of either data run or control task run and upper 4 bit specifies actions start stop poll as described below Lower 12 bit 0x100 0x101 0x102 0x103 list mode runs 0x200 0x201 0x202 0x203 fast list mode runs 0x301 MCA run 0x1 0x15 control task runs 0x3 adjust offsets 0x4 acquire ADC traces Upper 4 bit 0x1000 start new run 0x2000 resume run 0x3000 stop run and automatically store spectrum data 0x4000 poll 0x500x list mode special runs 0x5000 Parse list mode data file 0x5001 Locate list mode traces 0x5002 Read list mode traces 8 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved 0x5003 Read list mode energies 0x5004 Read list mode event PSA values 0x6000 stop list mode run during repeated runs 0x7000 manually read spectrum from module 0x8000 manually read spectrum from a MCA file 0x9000 stop any data run file _nameis a string variable which specifies the name of the output file It needs to have the complete file path Return values Value Description Error Handling 0 Success None lt 0 Data acquisition failed Check the error message re
70. t 256 This completes the list of values that control the trigger filter FPGAs The following input parameters are used by the DSP program They become active as soon as the first data taking run has been started Only then will the output parameters reflect the changes made to the set of input parameters TRACELENGTH This tells the DSP how many words of trace data to read The action XWAIT taken depends on FIFO length which is 4096 for all Rev D and Rev E modules If TraceLength lt FIFOlength the DSP will read from the FIFO In that case individual samples are 25ns apart If FIFOlength lt TraceLength the DSP will read from an FPGA register which mirrors the current ADC output In that case individual readings are at least 75ns apart In addition only post trigger data will be available because the DSP is then reading data in real time rather than data stored in a FIFO TraceLengths greater than FIFOlength are useful only when reading out only one channel In this case it allows acquiring a long trace to measure the exponential decay time of a preamplifier Currently the DGF 4C Viewer limits TraceLength not to exceed FIFOlength Extra wait states The time between recorded samples is AT 3 XWAIT 25ns XWAIT is used differently when acquiring untriggered traces in a control run with ControlTask 4 In this case the time between recorded samples is AT 3 25ns if XWAIT lt 3 XWAIT 25ns if 4 lt XWAIT lt 11 XWAIT 2
71. ted 22 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved RunTask Mode Trace CHANHEADLEN Capture 0 Slow control run N A N A 256 0x100 Standard list mode Yes 9 257 0x101 Compressed list mode Yes 9 258 0x102 Compressed list mode Yes 4 259 0x103 Compressed list mode Yes 2 512 0x200 Standard fast list mode No 9 513 0x201 Compressed fast list mode No 9 514 0x202 Compressed fast list mode No 4 515 0x203 Compressed fast list mode No 2 769 0x301 MCA mode No N A RunTask 0 is used to request slow control tasks These include programming the trigger filter FPGAs setting the DACs in the system transfers to from the external memory and calibration tasks RunTask 256 0x100 requests a standard list mode run In this run type all bells and whistles are available The scope of event processing includes computing energies to 16 bit accuracy and performing pulse shape analyses for improved energy resolution and better time of arrival measurements Nine words of results including time of arrival energy XIA pulse shape analysis user pulse shape analysis GSLTtimeA GSLTtimeB GSLTtimeC etc are written into the 1 O buffer for each channel Level 1 buffer is not used in this RunTask RunTask 257 0x101 requests a compressed list mode run Both Level 1 buffer and I O buffer are used in this RunTask but no traces are written into the I O b
72. tents of Global Name Arrays Array Names NUMBER MODULES CONTROLLER ID SCSI BUS CRATE ID Module Global Names CAMAC_ MASTER FAST_CAMAC LAM ENABLE C_LIBRARY RELEASE C_LIBRARY BUILD SLOT WAVE MODULE NUMBER MODULE CSRA MODULE CSRB MODULE _ FORMAT MAX EVENTS COINCIDENCE PATTERN ACTUAL _ COINCIDENCE WAIT MIN COINCIDENCE WAIT Global Data Names SYNCH_WAIT IN SYNCH RUN TYPE BUFFER HEAD LENGTH EVENT HEAD LENGTH CHANNEL HEAD LENGTH OUTPUT BUFFER LENGTH NUMBER EVENTS RUN_ TIME DECIMATION CHANNEL CSRA CHANNEL CSRB ENERGY RISETIME ENERGY FLATTOP TRIGGER RISETIME TRIGGER FLATTOP TRIGGER _ THRESHOLD VGAIN VOFFSET TRACE LENGTH TRACE DELAY PSA START PSA END EMIN BINFACTOR TAU BLCUT XDT BASELINE PERCENT CFD THRESHOLD MULTIPLICITY PULSE WIDTH LIVE TIME INPUT COUNT RATE User_Var Names Additionally a string array All Files containing the file names for the initialization is also needed Table 3 2 lists the file names needed to initialize two DGF 4C modules 14 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved Table 3 2 File Names in All Files All Files File Name Note All Files 0 CAXIADGF4C Firmware dgf4c bin System FPGA configurations All Files 1 C XIA DGF4C DSP DGF codeE bin DSP code All Files 2 C XTA DGF4C Configuration test itx Settings file C XIA DGF4C DSP DGFcodeE var File of DSP I O variable names All
73. the driver Usage example Set current module to 1 and current channel to 3 C Dgf4c Set Current ModChan 1 3 10 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved C_Dgf4c_Buffer_lO Syntax long C_Dgf4c Buffer IO unsigned short Values An unsigned 16 bit integer array containing the data to be transferred unsigned short type unsigned short direction char file name File name Description Use this function to 1 download or upload DSP parameters between the user interface and the DGF modules 2 save DSP parameters into a settings file or load DSP parameters from a settings file and applies to all modules present in the system 3 copy parameters from one module to others or extracts parameters from a settings file and applies to selected modules Parameter description Values is an unsigned 16 bit integer array used for data transfer between the user interface and DGF modules type specifies the I O type direction indicates the data flow direction The string variable file name contains the name of settings files Different combinations of the three parameters Values type direction designate different I O operations as listed in Table 2 2 Data transfer type Data transfer direction Table 2 2 Different I O operations using function C_Dgf4c_Buffer_IO Type Direction Values T O Operation 0 0 DSP I O variable value
74. uffer Nine words of results including time of arrival energy XIA pulse shape analysis user pulse shape analysis GSLTtimeA GSLTtimeB GSLTtimeC etc are written into the I O buffer for each channel RunTask 258 0x102 requests a compressed list mode run The only difference between RunTask 258 and 257 is that in RunTask 258 only four words of results time of arrival energy XIA pulse shape analysis user pulse shape analysis are written into the I O buffer for each channel RunTask 259 0x103 requests a compressed list mode run The only difference between RunTask 259 and 257 is that in RunTask 259 only two words of results time of arrival and energy are written into the I O buffer for each channel RunTask 512 0x200 employs the same internal data format as RunTask 256 but omits buffer full checks and trace capture The run is stopped when the required number of events MaxEvents has been acquired This run type uses the shortest possible interrupt routine for raw data gathering Hence it allows 23 DGF 4C Programmer s Manual V3 04 O XIA 2004 All rights reserved for the shortest time between two logged events For best results the channel variables PAFLength and TriggerDelay should be set to 1 for all channels involved i e the trace length for each channel should be set to 0 and bit 10 of ChanCSRA described in Section 4 2 for each channel should be cleared Level 1 buffer is not used in this run type Nine words of r
75. uld never assume to find any given buffer at a fixed address Note that addresses in the DSP data memory fall into the range from 0x4000 to Ox7FFF The word length in data memory is 16 bit If an address falls in the range from 0 to 0x3FFE it points to a location in program memory Here the word lengths are 24 bits USEROUT 16 words of user output data which may be used by user written DSP code 36 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved AOUTBUFFER Address of the I O buffer LOUTBUFFER Number of words in the I O buffer AECORR unused reserved LECORR unused reserved Formerly address and length of an array containing coefficients for energy calculations Now these coefficients are calculated in the DSP code from the decay time ATCORR unused reserved LTCORR unused reserved Formerly address and length of an array containing coefficients for normalization and time of arrival corrections Now these coefficients are calculated in the DSP code from the decay time HARDWAREID ID of the hardware version HARDVARIANT Variant of the hardware FIFOLENGTH Length of the onboard FIFOs measured in storage locations Rev D and Rev E DGF 4Cs have FIFOs with 4096 locations FIPPIID ID of the FiPPI FPGA configuration FIPPIVARIANT Variant of the FiPPI FPGA configuration INTRFCID ID of the CAMAC interface FPGA configuration INTRFCVARIANT Variant of the CAMAC interface FPGA configuration DSPRELE
76. ven in Table 3 6 3 DGF 4C Programmer s Manual V3 04 XIA 2004 All rights reserved 4 User_Var_Names is a string array containing variable names which are applicable to individual channels of individual modules e g channel CSR filter rise time filter flat top voltage gain and DC offset etc User_Var_Names currently can hold 64 names If less than 64 names are needed which is the current case the remaining names should be defined as empty strings A detailed description of User_Var_Names is given in Table 3 6 Name is a string variable used to select which set of names to be handed down It can be one of the following four choices ALL FILES MODULE GLOBAL NAMES GLOBAL DATA NAMES or USER VAR NAMES Return values Value Description Error Handling 0 Success None 1 Invalid name Check the second parameter Name Usage example download module global names define Module Global Names first C_Dgf4c Hand Down_Names Module Global Names MODULE GLOBAL NAMES download global data names define Global Data Names first C_Dgf4c Hand Down Names Global Data_Names GLOBAL DATA NAMES download user variable names define User Var Names first C Dgf4c Hand Down Names User Var Names USER VAR NAMES download file names define All Files first C_Dgf4c Hand Down Names All Files ALL FILES 4
77. will be interesting to those users who want to integrate the DGF 4C modules into their own data acquisition system The third section describes those user accessible variables that control the functions of the DGF 4C modules Those advanced and curious users can use this section to better understand the operation of the DGF 4C Additionally this manual also includes instructions on how to write User DSP code Appendix A and to control DGF modules using CAMAC commands Appendix B The scope of this document is all DGF 4C modules with serial numbers D1100 through D1199 and E1200 through E1299 Modules with serial numbers E1200 through E1299 have 14 bit ADCs as opposed to the 12 bit ADCs on other modules Modules with serial numbers D1100 through D1199 and E1200 through E1299 have 4K FIFOs which allow storing up to 4096 ADC samples for each channel 2 DGF 4C C Driver The DGF 4C C Driver consists of a group of C functions which can be used to configure DGF modules make MCA or list mode runs and retrieve data from DGF modules These functions can be compiled as a WaveMetrics Igor XOP file which is currently used by the DGF 4C Viewer a dynamic link library DLL or static library to be used in customized user interfaces or applications In order to better illustrate the usage of these functions an overview of the operation of DGF is given below and the usage of these functions is mentioned wherever appropriate At first the DGF 4C C Driver needs t

Programmer`s Manual Digital Gamma Finder (DGF)

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