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Programmer`s Manual PIXIE-4

1. download ENERGY RISETIME to the DSP retval Pixie User Par IO Channel Parameter Values 23 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved ENERGY RIS if retval lt 0 Error handling ETIME CHANNEL direction modnum channum Table 3 5 gives a complete description of all the global variables being used by the PIXIE 4 API Table 3 5 Descriptions of Global Variables in PIXIE 4 System_Parameter_Names VO Type Unit Corresponding DSP Variables NUMBER MODULES Read Write N A N A OFFLINE ANALYSIS Read Write N A N A C LIBRARY RELEASE Read only N A N A C_LIBRARY BUILD Read only N A N A SLOT_ WAVE Read Write N A N A Module Parameter_Names 1 O Type Unit Corresponding DSP Variables MODULE NUMBER Read only N A MODNUM MODULE CSRA Read Write N A MODCSRA MODULE CSRB Read Write N A MODCSRB MODULE FORMAT Read Write N A MODFORMAT MAX EVENTS Read Write N A MAXEVENTS COINCIDENCE PATTERN Read Write N A COINCPATTERN ACTUAL COINCIDENCE WAIT Read Write N A COINCWAIT MIN COINCIDENCE WAIT Read only N A COINCWAIT SYNCH WAIT Read Write N A SYNCH
2. Error handling wait until run has ended while Pixie Acquire Data 0x4100 User Data modnum read out the list mode data and save it to a file retval Pixie Acquire Data 0x6100 User Data DataFile modnum if retval lt 0 Error handling k if k gt Nruns break issue RESUME RUN command retval Pixie Acquire Data 0x2100 User Data modnum if retval lt 0 Error handling 27 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved while 1 read out the MCA spectrum and put it to array User Data retval Pixie Acquire Data 0x9001 User Data modnum if retval lt 0 Error handling To process the list mode data after it is saved to a file the PIXIE 4 API provides several utility routines to parse the list mode data and read out the waveform energy of each individual trace or PSA values The code below shows how to read waveforms from a list mode file An Example Code Illustrating How to Parse List Mode Data S32 retval U8 direction modnum channum i U32 List _Data 2 MAX NUMBER OF MODULES list mode trace information char DataFile C XIA PIXIE4 PulseShape Data bin U32 totaltraces total number of traces in the list mode data file U32 traceposlen point to positions of the traces in the file Ul6
3. All rights reserved Table 3 2 File Names in All Files All Files File Name Note All Files 0 C XJA PIXIE4 Firmware syspixie_revB bin Communication FPGA configurations Rev B All Files 1 C XTA PIXIE4 Firmware syspixie_revC bin Communication FPGA configurations Rev C All Files 2 C XTA PIXIE4 Firmware pixie bin Signal processing FPGA configurations All Files 3 CAXIAPIXIEADSPPXIcode bin DSP executable binary code All Files 4 CAXIAPIXIEA Configuration default set Settings file All Files 5 CAXIAPIXIEADSPPXIcode var File of DSP I O variable names All Files 6 C XJA PIXIE4 DSP PXIcode st File of DSP memory variable names The global variable array System Parameter Values also needs to be initialized before the API functions are 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 PIXIE 4 modules SLOT _WAVE 0 3 Module 0 sits in slot 3 SLOT _WAVE 1 4 Module 1 sits in slot 4 3 1 2 Boot PIXIE Modules The boot procedure for PIXIE 4 modules includes the following steps First all the global parameter names and boot file names should be downloaded by calling Pixie Hand_Down_Names Then function Pixie_User_Par_IO should be called to initialize the global value array Sys
4. 1 N 0011 3 To accept this event bit 3 in MODULEPATTERN must be set If all 16 bits are set all events are accepted NNSHAREPATTERN 16 bit user defined number defining which event hit pattern sets U00 XdatLength USERIN hit status to 1 which is then send to the neighboring modules if bit 8 in MODCSRA is set The bits are defined in the same way as in the COINCPATTERN 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 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 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 PIXIE 4 operation see the Channel CSRA Edit Panel reachable through the Settings tab of the PIXIE 4 Viewer In general setting the bit activates the option in question 36 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Respond to group triggers only Set this bit if you want to con
5. 16 bit words for notifying the API the trace position and length information Trace0 Ul6 malloc traceposlen 1 2 if Trace0 NULL Error handling Trace0 0 traceposlen 0 position of the first trace Trace0 1 traceposlen 1 length of the first trace read out the first trace and put it into trace0 retval Pixie Acquire Data 0x7003 trace0 DataFile modnum if retval lt 0 Error handling 29 PIXIE 4 Programmer s Manual V1 41 XIA 2007 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 PIXIE 4 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 PXIcode var which contains in a 2 column format the offset and name of every user accessible variable We sugge
6. Handling 0 Success None 1 Null pointer for User Par Values Check User Par Values 2 Invalid user parameter name Check User Par Name 3 Invalid user parameter type Check User Par Type 4 Invalid T O direction Check direction 5 Invalid Pixie module number Check ModNum 6 Invalid Pixie channel number Check ChanNum Usage example Ul6 direction modnum channum S32 retval direction 0 download modnum 0 Module 0 channum 1 Channel 1 set module parameter COINCIDENCE PATTERN to OxFFFF Module Parameter Values Coincidence Pattern Index 0xFFFF download COINCI DENCE PATTERN to the DSP retval Pixie User Par IO Module Parameter Values COINCIDENCE PATTERN MODULE direction modnum channum if retval lt 0 error handling set channel parameter ENERGY RISETIME to 6 0 us 7 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Channel Parameter Values ENERGY RISETIME Index 6 0 download ENERGY RISETIME to DSP retval Pixi _User Par IO Channel Parameter Values ENERGY RISETIME CHANNEL direction modnum channum if retval lt 0 error handling 8 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Pixie_Acquire_Data Syntax S32 Pixie
7. a data run 0x3000 stop a data run 0x4000 poll run status 0x5000 read histogram data and save it to a file 0x6000 read list mode buffer data and save it to a file 0x7000 offline list mode data parse routines 0x7001 parse list mode data file 9 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved 0x7002 locate traces 0x7003 read traces 0x7004 read energies 0x7005 read PSA values 0x7006 read extended PSA values 0x7007 locate events 0x7008 read event 0x8000 manually read MCA histogram from a MCA file 0x9000 external memory EM I O 0x9001 read histogram memory section of EM 0x9002 write to histogram memory section of EM 0x9003 read list mode memory section of EM 0x9004 write to list mode memory section of EM User_data has the following format for the run types listed below 0x4 Get ADC traces Length must be ADCTraceLen NumberOfChannels i e 8192 4 32k All array elements are return values the Nth 8k of data are the ADC trace of channel N 0x7001 Parse list mode data file Length must be 2 MaxNumModules i e 16 or 34 All array elements are return values User_data i NumEvents of module i User_data itMaxNumModules TotalTraces of module I 0x7002 Locate Traces of all events Length must be TotalTraces of ModNum 3 NumberOfChannels All array elements are return values User_data i 3n Location of channel n s trace in file for event i word number User_data i 3n 1 length of channel n s trace Us
8. 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 PIXIE 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 to 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 52 PIXIE 4 Programmer s Manual V1 41 XIA 2007 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 setti
9. direction modnum channum if retval lt 0 Error handling T retval Pixie User Par IO System Parameter Values SLOT WAVE SYSTEM direction modnum channum if retval lt 0 Error handling boot PIXIE 4 modules retval Pixie Boot _System 0x1F if retval lt 0 Error handling set current module and channel number Pixie Set Current ModChan 0 0 22 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved 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 while 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 PXIcode 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
10. 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 and the 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 i e only 2 words are available in RunTask 0x102 or 0x202 and no words in RunTask 0x103 or 0x203 53 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved When entering UserChannel or UserEvent the address register 15 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 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
11. 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 AOUTBUFFER Address of the list mode data buffer LOUTBUFFER Number of words in the list mode 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 FIPPIID ID of the FiPPI FPGA configuration FIPPIVARIANT Variant of the FiPPI FPGA configuration INTRFCID ID of the system FPGA configuration INTRFCVARIANT Variant of the system FPGA configuration DSPRELEASE _ DSP software release number DSPBUILD DSP software build number The following channel variables contain run statistics Again the
12. root results MCAsum Wave root results traceO Wave root results tracel Wave root results trace2 Wave root results trace3 Wave root results eventposlen Wave root results eventwave NewDataFolder o root user Channel 0 histogram Channel 1 histogram Channel 2 histogram Channel 3 histogram Sum histogram channel 0 list mode trace channel 1 list mode trace channel 2 list mode trace channel 3 list mode trace contains trace location in list mode file contains selected list mode event create the folder for variables defined by user Variable G root user UserVersion the version of the user function calls defined by XIA Variable G root user UserVariant the variant of the code written by the user 57 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved
13. the MCA run retval Pixie Acquire Data 0x3301 User Data modnum if retval lt 0 Error handling save MCA spectrum to a file retval Pixie Acquire Data 0x5301 User Data C XIA Pixie4 MCA Data0001 bin modnum if retval lt 0 Error handling read out the MCA spectrum and put it to array User data retval Pixie Acquire Data 0x9001 User data modnum if retval lt 0 Error handling Note that in clover addback mode the spectrum length is fixed to 16K for each channel plus 16K of addback spectrum Therefore the starting address ofthe MCA spectrum in the external memory for Channel 0 1 2 and 3 will be 0x00000000 0x000040000 0x00008000 0x00010000 respectively for the addback spectrum it is 0x00018000 3 3 2 Access list mode data The list mode data in the linear output data buffer can be written in a number of formats User code should access the three variables BUFHEADLEN EVENTHEADLEN and CHANHEADLEN in the configuration file of a particular run to navigate through the data set There are two data buffers to choose from the DSP s local I O buffer 8K 16 bit words and section of the external memory 128K 32 bit words The target data buffer is selected by setting bit 1 in the variable MODCSRA If the external buffer is chosen to hold the output data the local buffer is transferred to the external memory when it
14. 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 46 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved 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 16 13 3ns 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 47 PIXIE 4 Programmer s Manual V1 41 XIA 2007 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 task
15. vas esac issue a odes caia 30 427 Channel variablesiisezssicasi ana a E Mantes E e E E EE RA 36 Control TasKS uu ds 48 Appendix A User supplied DSP code ooooonoocnnoccoocccoonnononconncconocono nono nconccconocananonnnos 51 Gedy troduction a A A A E E E AE E 51 6 2 The development environment tad rd da aia 51 6 3 Interfacing user code to XIA s DSP COd6 oooooncccnococonncononononconncconocono nono cconccco nacion 51 6 4 o 8b cee epee ee RO a eg Te ee E er eae ee 52 6 50 Debugging tools ana 55 Appendix B User supplied Igor code ooooocccnococonociconononconccconoconn nono cconccco no conc nnnnnno 55 TL igor A A a E a rats us aoe a A E 55 T2 Teo User Panels iaaa a 56 Ea Igor User VanablEsian cn 56 11 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved 1 Overview This manual is divided into three major sections The first section is a description of the PIXIE 4 application program interface API Advanced users can build their own user interface using these API functions The second section is a reference guide to program the PIXIE 4 modules using the PIXIE 4 API This will be interesting to those users who want to integrate the PIXIE 4 modules into their own data acquisition system The third section describes those user accessible variables that control the functions of the PIXIE 4 modules Those advanced and curious users can use this section to better understand the operation of the PIXIE 4 Addi
16. 8 Bit 9 Bit 10 Bit 11 Bit 2 Bit 15 Function 0 0 Triggers are distributed within module only no connection to backplane 1 0 Module shares triggers using bussed wire OR line In systems with less than 8 modules and no PXI bridge boundaries all modules sharing trigger should be set this way 0 1 Module receives triggers from master trigger lines but uses neighboring lines to distribute triggers from right to left In systems with more than 7 modules and orPXI bridge boundaries all modules except the leftmost should be set this way 1 1 Module puts own triggers and triggers received from right neighbor on the master trigger lines and responds to triggers on master trigger line In systems with more than 7 modules and orPXI bridge boundaries the leftmost module should be set this way If set compute sum of channel energies for events with more hits in more than one channel and put into addback spectrum If set spectra for individual channels contain only events with a single hit Only effective if bit 3 is set also If set use signal on front panel input DSP OUT between channel 1 and 2 and distribute on backplane to all modules as Veto signal GFLT Note that only one module may enable this options to avoid a conflict on the backplane If set send hit status from left AND local hit status to right neighbor else only send local hit status only The hit status is 1 in each ev
17. Acquire Data U16 Run_Type Data acquisition run type U32 User data An unsigned 32 bit integer array containing the data to be transferred U8 file name Name of the file used to store list mode or MCA histogram data U8 ModNum The number of the Pixie module Description Use this function to acquire ADC traces MCA histogram 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 task 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 gt 0x15 control task runs Upper 4 bit 0x0000 start a control task run 0x1000 start a new data run 0x2000 resume
18. NGTH The rise time of the trigger filter depends on FastLength FASTGAP RiseTime FastLength 13 3 ns Note the constraint FastLength lt 32 The flat top of the trigger filter depends on FastGap FlatTop FastGap 13 3 ns There is a constraint concerning the sum value of the two parameters FastLength FastGap lt 32 PEAKSAMPLE This variable determines at what time the value from the energy filter PEAKSEP will be sampled Note that the following formulae depend on the filter range Filter Range 0 PeakSample max 0 SlowLength Slow Gap 7 Filter Range 1 PeakSample max 2 SlowLength Slow Gap 4 Filter Range 2 PeakSample SlowLength Slow Gap 2 Filter Range gt 3 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 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 39 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved If PeakSep gt 33 PeakSep PeakSample 1 Note the constraint 0 lt
19. PeakSep PeakSample lt 7 FASTADCTHR Reserved 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 of the PIXIE 4 Viewer MINWIDTH Unused MAXWIDTH This value aids the pile up inspector MaxWidth is the maximum duration in sample clock ticks 13 3 ns 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 13 3 ns Note the constraint Max Width 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 Max Width cut is too tight there will be a loss of efficiency in the main peak Setting Max Width 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 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 capturi
20. Programmer s Manual Digital Gamma Finder DGF PIXIE 4 Version 1 41 February 2007 XIA LLC 31057 Genstar Road Hayward CA 94544 USA Phone 510 401 5760 Fax 510 401 5761 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 Table of Contents Nn o O a a n a a e a A a a E cares 1 PAE A AR Dy sic egy asses tain scih tay ii 1 Pane Hand Down Names O 3 Pixie BOSSA E 5 Pixie User Parla das 6 Pixie Acquire Dita ao 9 Pixie Set Current MA sa 15 A A E au saa bettas 16 Options for Compiling PIXIE4A APT ansia idea 19 Control PIXIE 4 Modules via CompactPCl oooonoccnicccinccconccconoconcnonnnconccconocanononncconncnnns 20 A O A genau E E E A E N 20 3 1 1 Initialize Global Variables UNS ld oasis 20 3 1 2 Boot PIXIE Modules e a a Ra 21 3 20 Setting DSP variabl s it aaa 23 3 3 Access spectrum memory or list mode data ooooonnccnnccinccconcnconncconoconn nono nonnncconacnnns 25 3 3 1 Access spectrum MEMO iS 25 3 3 2 Access list mode datdie adas 26 User Accessible Variables NA aii A A a a aeons 30 4 1 DMI parameters aiem een e
21. Trace0 point to the first trace in the file direction 0 download modnum 0 Module 0 channum 0 Channel 0 start a general list mode run retval Pixie Acquire Data 0x1100 List Data modnum if retval lt 0 Error handling wait until run has ended while Pixie Acquire Data 0x4100 List Data modnum read out the list mode data and save it to a file retval Pixie Acquire Data 0x6100 List Data DataFile modnum if retval lt 0 Error handling parse list mode file retval Pixie Acquire Data 0x7001 List Data DataFile modnum if retval lt 0 Error handling totaltraces 0 28 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved for i 0 i lt MAX NUMBER _OF MODULES i sum the total number of traces for all modules totaltraces List Data i MAX NUMBER OF MODULES allocate memory to hold the starting address trace length and energy of each trace therefore 3 32 bit words are needed for each trace traceposlen U32 malloc totaltraces 3 NUMBER OF CHANNELS if traceposlen NULL Error handling locate traces in the data file retval Pixie Acquire Data 0x7002 traceposlen DataFile modnum if retval lt 0 Error handling allocate memory to hold the first trace 2 extra
22. WAIT IN SYNCH Read Write N A INSYNCH RUN TYPE Write only N A RUNTASK FILTER RANGE Read Write N A FILTERRANGE BUFFER HEAD LENGTH Read only N A BUFHEADLEN EVENT HEAD LENGTH Read only N A EVENTHEADLEN CHANNEL HEAD LENGTH Read only N A CHANHEADLEN OUTPUT BUFFER LENGTH Read only N A LOUTBUFFER NUMBER EVENTS Read only N A NUMEVENTSA NUMEVENTSB RUN_TIME Read only s RUNTIMEA RUNTIMEB RUNTIMEC BOARD VERSION Read only N A N A SERIAL NUMBER Read only N A N A Channel Parameter _ Names I O Type Unit Corresponding DSP Variables CHANNEL CSRA Read Write N A CHANCSRA CHANNEL CSRB Read Write N A CHANCSRB ENERGY RISETIME Read Write us SLOWLENGTH ENERGY FLATTOP Read Write us SLOWGAP TRIGGER RISETIME Read Write us FASTLENGTH TRIGGER FLATTOP Read Write us FASTGAP TRIGGER THRESHOLD Read Write N A FASTTHRESH VGAIN Read Write V V GAINDAC 24 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved VOFFSET Read Write V TRACKDAC TRACE LENGTH Read Write us TRACELENGTH TRACE DELAY Read Write us TRIGGERDELAY PSA START Read Write us PSAOFFSET PSA END Read Write us PSALENGTH EMIN Read Write N A ENERGYLOW BINFACTOR Read Write N A LOG2EBIN TAU Read Write us PREAMPTAUA PREAMPTAUB BLCUT Read Write N A BLCUT XDT Read Write N A XWAIT BASELINE PERCENT Read Write N A BASELINEPERCENT CFD THRESHOLD Read Write N A CFDTHR INTEGRATOR Read Wr
23. _Acquire_Data By setting different run types it can be used to start stop 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 Pixie modules After checking the quality of a MCA spectrum a Pixie user may decide to change one or more settings like energy filter rise time or flat top The function used to change Pixie settings is Pixie User_Par_IO This function converts a user parameter like energy filter rise time in us into a number understood by the Pixie hardware or vice versa Another function Pixie_Buffer_IO is used to read data from DSP s internal memory to the host or write data from the host into the internal memory This is useful for diagnosing Pixie 1 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved modules by looking at their internal memory values The other usage of this function is to read save copy or extract Pixie s configurations though its settings files In a multi module Pixie 4 system it is essential for the host to know which module or channel it is communicating to The function Pixie _Set_Current_ModChan is used to set the current module and channel The detailed description of each function is given below 2 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Pixie_Hand_Down_Names Syntax S32 Pixie Hand Down Names U8 Names An ar
24. anel input DSP OUT to the Status backplane line Note that Status is defined as active low so a logic 1 3 3V at the front panel corresponds to a logic 1 OV on the Status line Since Status is a wire OR line more than one module may enable this option at the same time It also can enabled at the same time as the Veto option if necessary If set the front panel input DSP out is connected as an input to the Status line on the backplane The Status line is set up as a wire OR so more than one module can enable this option Controls sharing of triggers over backplane See bit 2 Execute user code routines programmed in user dsp Reserved for user code MODFORMAT List mode data format descriptor Currently it is not in use CHANNUM The chosen channel number of a Pixie module Mainly used by the host to set the designated channel RUNTASK This variable tells the Pixie 4 what kind of run to start in response to a run start request Nine run tasks are currently supported 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 mo
25. arameters 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 Pixie modules i e the Boot_Pattern should be Ox1F Return values Value Description Error Handling 0 Success None 1 Unable to scan crate slots Check PXI slot map 2 Unable to read communication FPGA configuration Rev B Check comFPGA file 3 Unable to read communication FPGA configuration Rev C Check comFPGA file 4 Unable to read signal processing FPGA configuration Check SPFPGA file 5 Unable to read DSP executable code Check DSP code file 6 Unable to read DSP parameter values Check DSP parameter file 7 Unable to initialize DSP parameter names Check DSP var file 8 Failed to boot all modules present in the system Check Pixie modules Usage example S32 intval retval Pixie Boot System 0x1F if ret lt 0 error handling 5 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Pixie User Par_lO Syntax S32 Pixie User Par IO double User Par Values A double precision array containing the user parameters to be transferred U8 User Par Name A string variable indicating which user parameter is being transferred U8 User Par Type A string variable indicating which type of user parameters is being transferred Ul6 Direction 1 0 direct
26. 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 54 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved 6 5 Debugging tools Besides the debugging tools that are accessible through the PIXIE 4 Viewer it is also possible to download data into the PIXIE 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 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 output buffer the address and length of which are giv
27. d I O type Check type Usage example S32 retval U8 type modnum 0 direction modnum Module number Download DSP parameters to the current Pixie module DSP Values is a pointer pointing to the DSP parameters no need to specify file name here direction 0 Write type 0 DSP I O values direction retval Pixie Buffer IO DSP Values type if retval lt 0 Read Error handling wi modnum DSP memory values from the current PIXIE module Memory Values is a pointer pointing to the memory block no need to specify file name Here direction 1 Read type 1 DSP memory values retval Pixie Buffer IO Memory Values type direction modnum 17 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved if retval lt 0 Error handling 18 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Options for Compiling PIXIE 4 API Pixie 4 API can be compiled as either a WaveMetrics Igor XOP file which is currently used by the Pixie 4 Viewer a dynamic link library DLL or static library The two latter options can be used by advanced users to integrate Pixie modules into their own data acquisition systems The following table summarizes the required files for these options Table 2 3 Options for compiling the PIXIE 4 C Driver Compilati
28. de No 2 769 0x301 MCA mode No N A 32 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved 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 etc are written into the I 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 buffer Nine words of results including time of arrival energy XIA pulse shape analysis user pulse shape analysis 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 reques
29. ecuted 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 51 PIXIE 4 Programmer s Manual V1 41 XIA 2007 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 from 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
30. eeds to have the complete file path ModNum is the number of the module addressed counting from 0 to number of modules 1 If ModNum number of modules all modules are addressed in a for loop however this option is not valid for all RunTypes Return values Return values depend on the run type Run type 0x0000 11 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Value Description Error Handling 0 Success None 0x1 Invalid Pixie module number Check ModNum 0x2 Failure to adjust offsets Reboot the module 0x3 Failure to acquire ADC traces Reboot the module 0x4 Failure to start the control task run Reboot the module Run type 0x1000 Value Description Error Handling 0x10 Success None 0x11 Invalid Pixie module number Check ModNum 0x12 Failure to start the data run Reboot the module Run type 0x2000 Value Description Error Handling 0x20 Success None 0x21 Invalid Pixie module number Check ModNum 0x22 Failure to resume the data run Reboot the module Run type 0x3000 Value Description Error Handling 0x30 Success None 0x31 Invalid Pixie module number Check ModNum 0x32 Failure to end the run Reboot the module Run type 0x4000 Value Description Error Handling 0 No run is
31. en 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 48 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved ControlTask 4 ControlTask 5 ControlTask 6 the trigger polarity setting 1 e bit 5 of the 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 1638 units is chosen For bipolar signals like the induced waveforms from a segmented detector the ADC offset would be 8192 units 1 e midway between 0 and 16384 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 PIXIE 4 input The control task makes 16 measurements at each DAC step and uses the last computed DC offset value to enter into the data 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
32. en in the variables AOUTBUFFER and LOUTBUFFER Next the user starts a data run and reads the results after the run has ended 7 Appendix B User supplied Igor code Starting in version 1 38 Igor contains a number of user procedures that are called at certain points in the operation These user procedures are contained in a separate Igor procedure file user ipf that is automatically loaded when opening the Pixie Viewer Pixie4 pxp By default the user procedures do nothing but they can be edited to perform custom functions It is recommended that the modified procedures be saved as a new procedure file user XXX ipf and the generic user ipf be removed killed from the main pxp file 7 1 Igor User Procedures The Igor user procedures called from the current version of the main code are listed below Function User_Globals This function is called from InitGlobals It can be used to define and create global specific for the user procedures By default it creates a user variable UserVariant which can be used to track and identify different user procedure code variants Variant numbers 0x7FFF are reserved for user code written by XIA Function User_StartRun This function is called at end of Pixie_StartRun which is executed at beginning of a data acquisition run for runs with polling time gt 0 It can be used to set up customized runs i e initialize parameters etc Function User_NewFileDuringRun When Ig
33. ent if a module s hit pattern matches the NNSHAREPATTERN defined by the user If set send hit status from right AND local hit status to left neighbor else only send local hit status only The hit status is 1 in each event if a module s hit pattern matches the NNSHAREPATTERN defined by the user If set perform module coincidence test during event acquisition If set and bit 8 set also send a logic 1 to left neighbor if the channel hit pattern matches the NNSHAREPATTERN and send a logic 0 if it does not match If bit 9 is not set but bit 8 is set always send a logic 0 If set and bit 8 set also send a logic 1 to right neighbor if the channel hit pattern matches the NNSHAREPATTERN and send a logic 0 if it does not match If bit 10 is not set but bit 8 is set always send a logic 0 If set and bit 8 set also contribute a logic 1 to the Status backplane line if the channel hit pattern matches the NNSHAREPATTERN The backplane line functions as a wire OR line it is logic 1 if any module contributes a 1 31 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Bit 12 Bit 13 Bit 14 Bit 15 MODCSRB Bit 0 Bits 1 15 If set and bit 8 set also contribute a logic 1 to the Token backplane line if the channel hit pattern matches the NNSHAREPATTERN The backplane line functions as a wire OR line it is logic 1 if any module contributes a 1 If set contribute the front p
34. ent i User_data i 8n 6 Unused3 word of channel n for event i User_data i 8n 7 RealTimeHi word of channel n for event i 0x7007 Locate all events Length must be NumEvents of ModNum 3 All array elements are return values User_data 1 3 Location of event i in file word number User_data 1 3 1 Location of buffer header start for event i in file User_data 1 3 2 Length of event i event header channel header traces 0x7008 Read one event Length must be length of selected event 7 36 this is longer than actually used but ensures enough room for channel headers in all runtypes First 3 elements are input values User_data 0 Location of selected event in file word number User_data 1 Location of buffer header start for selected event in file User_data 2 Length of selected event The remaining array elements are return values User_data 3 6 are the tracelengths of channel 0 3 User_data 7 6 BHL contain the buffer header corresponding to the selected event User_data 7 BHL 6 BHL EHL contain the event header User_data 7 BHL ELH 6 BHL EHL 4 CHL are the channel headers for channel 0 3 always 9 words per channel header but in compressed runtypes some entries are be invalid User_data 7 BHL EHL 4 CHL contain the traces of channel 0 3 followed by some undefined values use tracelength to parse traces file_name is a string variable which specifies the name of the output file It n
35. er_data 1 3n 2 energy for channel n 0x7003 Read Traces of one event Length must be NumberOfChannels 2 combined tracelength of channels First NumberOfChannels 2 elements are input values User_data 2n Location of channel n s data in file for selected event word number User_data 2n 1 length of channel n s trace The remaining array elements are return values User_data 8 Trace data of channel 0 followed by channels 1 2 and 3 0x7004 Read Energies of all events Length must be NumEvents of ModNum NumberOfChannels All array elements are return values User_data 1 4 n energy of channel n for event i 0x7005 Read PSA values of all events Length must be NumEvents of ModNum 2 NumberOfChannels All array elements are return values 10 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved User_data i 2n XIAPSA word of channel n for event i User_data i 2n 1 UserPSA word of channel n for event i 0x7006 Read extended PSA values of all events Length must be NumEvents of ModNum 8 NumberOfChannels All array elements are return values User_data i 8n timestamp word of channel n for event i User_data i 8n 1 energy word of channel n for event i User_data i 8n 2 XIAPSA word of channel n for event i User_data 1 8n 3 UserPSA word of channel n for event i User_data 1 8n 4 Unused word of channel n for event i User_data 1 8n 5 Unused2 word of channel n for ev
36. f 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 Bits 2 and 3 are used in MPI custom code 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 GAINDAC Reserved and not supported TRACKDAC This DAC determines the DC offset voltage The offset can be calculated using the following formula Offset V 2 5 32768 TRACKDAC 32768 SGA The index of the relay combinations of the switchable gain amplifier DIGGAIN The digital gain factor for compensating the difference between the user desired voltage gain and the SGA gain UNUSEDAO or UNUSEDA1 Reserved The following block of data contains trigger filter FPGA data Once a new variable has been written to DSP memory it has to be activated by starting a run with RunTask 0 Set DACs 38 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved and ControlTask 5 Program FiPPI SLOWLENGTH The rise time of the energy filter depends on SlowLength RiseTime SlowLength 2 FilterRange 13 3 ns SLOWGAP The flat top of the energy filter depends on SlowGap FlatTop SlowGap 2 FilterRange 13 3 ns There is a constraint concerning the sum value of the two parameters SlowLength SlowGap lt 127 FASTLE
37. follows For a given dt in us calculate the integer intdt dt 0 0133 If intdt gt 13 XAVG floor 65536 intdt 3 5 If intdt lt 13 XAVG 65535 UNUSEDBO0 or UNUSEDBI Reserved CFDREG Reserved for FPGA based constant fraction discriminator LOG2BWEIGHT The PIXIE 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 cf control task 6 the PIXIE will internally adjust the effective Log2Bweight for best energy resolution up to the maximum value given by LOG2BWEIGHT Hence the Log2Bweight 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 43 PIXIE 4 Pro
38. grammer s Manual V1 41 XIA 2007 All rights reserved parameter does not need to be adjusted afterwards 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 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 PIXIE 4 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 words 1 block of 32 is reserved for module data 4 blocks of 32 words each hold channel data 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 655362 RealTimeB 65536 RealTimeC 13 3ns RUNTIMEA RUNTIMEB RUNTIMEC The 48 bit run time clock A B C words are as for the RealTime clock Thi
39. hape analysis user pulse shape analysis are written into the I O buffer for each channel 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 always 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 PIXIE 4 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 MAXEVENTS The module ends its run when this number of events has been acquired In PIXIE 4 Viewer MAXEVENTS is automatically calculated when a run mode is chosen from the run type pulldown menu The calculation is based on
40. has been filled Then the run resumes automatically without interference from the host until 32 local buffers have been transferred The data can then be read from external memory in a fast block read starting from location 0x00020000 If the local buffer is chosen the run stops when the local buffer is filled The data has to be read out from local memory 26 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved With any data buffer you can do any number of runs in a row The first run would be started as a NEW run This clears all histograms and run statistics in the memory Once the data has been read out you can RESUME running Each RESUME run will acquire another either 32 or 1 8K buffers of data depending on which buffer has been chosen In a RESUME run the histogram memory is kept intact and you can accumulate spectra over many runs The example code shown below illustrates this An Example Code Illustrating How to Access List Mode Data S32 retval U8 direction modnum channum U32 User Data 131072 an array for holding the MCA spectrum data of 4 channels U16 k Nruns char DataFile C XIA PIXIE4 PulseShape Data bin direction 0 download modnum 0 Module 0 channum 0 Channel 0 Nruns 10 10 repeated list mode runs k 0 initialize counter start a general list mode run retval Pixie Acquire Data 0x1100 User Data modnum if retval lt 0
41. hown in Table 2 1 Table 2 1 The Combination of User_Par_Name and User_Par_Values User Par Values User_Par_ Type Name Size Data Type SYSTEM System Parameter_Values 64 Double precision MODULE Module Parameter_Values 64x7 Double precision CHANNEL Channel Parameter Values 64x7x4 Double precision 6 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved The way to fill the Channel_Parameter_Values array 1s to fill the channel first then the module For instance first 64 values are stored in the array for channel 0 and then repeat this for other three channels After that 64x4 values have been filled for module 0 Then repeat this for the remaining modules For the Module_Parameter_Values array first store 64 values for module 0 and then repeat this for the other modules User Par Name is the name of the variable which is to be transferred It is one element of either System Parameter Names or Module_Parameter_Names or Channel Parameter_Names direction indicates the transfer direction of parameters 0 download write parameters from the user interface to the API 1 upload read parameters from the API to the user interface ModNum is the number of the Pixie module being communicated to ChanNum is the channel number of the Pixie module being communicated to Return values Value Description Error
42. in progress N A 1 Run is in progress N A CSR value When run type 0x40FF N A 0x41 Invalid Pixie module number Check ModNum Run type 0x5000 Value Description Error Handling 0x50 Success None 0x51 Failure to save histogram data to a file Check the file name Run type 0x6000 Value Description Error Handling 0x60 Success None 0x61 Failure to save list mode data to a file Check the file name Run type 0x7000 12 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Value Description Error Handling 0x70 Success None 0x71 Failure to parse the list mode data file Check list mode data file 0x72 Failure to locate list mode traces Check list mode data file 0x73 Failure to read list mode traces Check list mode data file 0x74 Failure to read event energies Check list mode data file 0x75 Failure to read PSA values Check list mode data file 0x76 Failure to read extended PSA values Check list mode data file 0x77 Failure to locate events Check list mode data file 0x78 Failure to read events Check list mode data file 0x79 Invalid list mode parse analysis request Check run type Run type 0x8000 Value Description Error Handling 0x80 Success None 0x81 Failure to read out MCA spectrum from the file Check the MCA data file Run type 0x9000 Value Desc
43. ion read or write US ModNum Number of the module to work on U8 ChaNum Channel number of the Pixie module Description Use this function to transfer user parameters between the user interface the API and DSP s I O memory Some of these parameters User Par Type SYSTEM are applicable to all Pixie modules in the system like the total number of Pixie modules in the system Other parameters User Par Type MODULE are applicable to a whole Pixie module independent of its four channels e g coincidence pattern Module CSRA etc The final set of parameters User Par Type CHANNEL are applicable to each individual channel in a Pixie module e g energy filter settings or voltage gain etc 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 API this function will call another function UA_PAR IO which first converts these parameters into numbers that are recognized by both the DSP and the API 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 Type 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 Type is s
44. ite N A FTPWIDTH LIVE_TIME Read only s LIVETIMEA LIVETIMEB LIVETIMEC INPUT _COUNT_ RATE Read only cps FASTPEAKSA FASTPEAKSB FASTPEAKSC LIVETIMEA LIVETIMEB LIVETIMEC FAST PEAKS Read only N A FASTPEAKSA FASTPEAKSB FASTPEAKSC 3 3 Access spectrum memory or list mode data 3 3 1 Access spectrum memory The MCA spectrum memory is fixed to 32K words 32 bits per word per channel residing in the external memory Therefore the starting address of the MCA spectrum in the external memory for Channel 0 1 2 and 3 will be 0x00000000 0x000080000 0x00010000 0x00018000 respectively The reading out of the spectrum memory to the host is through the PCI burst read at rates over 100 Mbytes s The spectrum memory is accessible even when a data acquisition run is in progress The following code is an example of how to start a MCA run and read out the MCA spectrum after the run is finished An Example Code Illustrating How to Access MCA Spectrum Memory S32 retval U8 direction modnum channum U32 User Data 131072 an array for holding the MCA spectrum data of 4 channels direction 0 download modnum 0 Module 0 channum 0 Channel 0 start a MCA run retval Pixie Acquire Data 0x1301 User Data modnum if retval lt 0 Error handling 25 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved wait for 30 seconds Sleep 30000 stop
45. la B1 BIL B1H 65536 20 11 ERRANGES BO BOL B0H 65536 200 TP RRANCE S TAU PreampTauA PreampTauB 65536 Baseline B 1 B0 exp 0 0133 SlowLength SlowGap 2 TRANGE 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 set to zero while running ControlTask 6 reserved 50 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved 6 Appendix A User supplied DSP code 6 1 Introduction It is possible for users to enhance the capabilities of the PIXIE 4 by adding their own DSP code XIA provides an interface on the DSP level and has built support for this into the PIXIE 4 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 and 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 2185 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
46. les are driven 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 The timers are reset when the entire system actually starts the run After run start InSynch is automatically set to 1 A 4 word data block that is used to specify command options Set this variable to 1 to resume a data run otherwise set it to 0 Set to 2 before stopping a list mode run prematurely 35 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved FILTERRANGE The energy filter range downloaded from the host to the DSP It sets the number of ADC samples 2 FILTERRANGE to be averaged before entering the filtering logic The currently supported filer range in the signal processing FPGA includes 1 2 3 4 5 and 6 MODULEPATTERN 16 bit user defined number controlling which combination of neighbor lines and backplane status lines are acceptable to record an event Active only if bit 8 in MODCSRA is set The bits in MODULEPATTERN correspond to the status of the neighbor and backplane lines in a similar way as the COINCPATTERN relates to the channel hit pattern The four status lines Token Status Right Left form a number N from 0 to 16 A line combination is acceptable if bit N is set For example if both neighbor lines are logic
47. lowing variables affect internal MCA histogramming of the PIXIE 4 module ENERGYLOW Start energy histogram at ENERGYLOW Only applies to list mode runs LOG2EBIN This variable controls the binning of the histogram Energy values are CFDTHR PSAOFFSET calculated to 16 bits precision The LSB corresponds to 1 4 of a 14 bit ADC The PIXIEs 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 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 The 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
48. modules in a Pixie system e g number of Pixie modules in the chassis etc System Parameter 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 System_Parameter_Names is given in Table 3 5 3 MODULE This indicates we are downloading Module Parameter Names Module Parameter Names are those global variables that are applicable to each individual module e g module number module CSR coincidence pattern and run type etc Module Parameter 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 Module Parameter Names is given in Table 3 5 3 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved 4 CHANNEL This indicates we are downloading Channel Parameter Names Channel Parameter Names are those global variables that are applicable to individual channels of the Pixie modules e g channel CSR filter rise time filter flat top voltage gain and DC offset etc Channel_Parameter_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 Channel Parameter Names is given in Table 3 5 Return values Value Description Error Handling 0 Success No
49. 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 CHANNUM The XWAIT variable determines the time between successive ADC samples samples are XWAIT 13 3ns apart In the PIXIE 4 Viewer XWAIT 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 PIXIE 4 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 ProgramFiPPI This task writes all relevant data to the FiPPI control registers Measure Baselines This routine is used to collect baseline values Currently DSP collects 49 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved ControlTask 9 23 six words BOL BOH B1L 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 formu
50. n at the end of the coincidence window suppress further hits reporting by late channels In the PIXIE 4 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 data Secondly when using a filter range of 6 in the FPGA the minimum value for COINCWAIT is larger than 1 in all circumstances Use the following formula to determine COINCWAIT COINCWAIT Max PeakSep 2 FilterRange eno ch3 Min PeakSep 2 FilterRange cho ch3 Choose COINCWAIT big enough such that the requirements of all channels in the module are met SYNCHWAIT Controls run start behavior When set to 0 the module simply starts or INSYNCH HOSTIO RESUME resumes a run in response to the corresponding request When set to 1 one or multi modules will run synchronously through the backplane This kind of set up in connection with SyncWait 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 Pixie system is only partially active InSynch is an input output variable It is used in multi Pixie systems in which the modu
51. ne 1 Invalid name Check the second parameter Name Usage example S32 retval download system parameter names define System Parameter Names first retval Pixie Hand Down Names System Parameter Names SYSTEM if retval lt 0 error handling download module parameter names define Module Parameter Names first retval Pixi _Hand_Down_Names Module Parameter Names MODULE if retval lt 0 error handling download channel parameter names define Channel Parameter Names first retval Pixi _Hand_Down_Names Channel Parameter Names CHANNEL if retval lt 0 error handling download boot file names define All Files first retval Pixi _Hand_Down_Names All Files ALL FILES if retval lt 0 error handling 4 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Pixie_Boot_System Syntax S32 Pixie Boot System U16 Boot Pattern The Pixie 4 boot pattern Description Use this function to boot all Pixie modules in the system Before booting the modules it scans all PXI crate slots and finds the address for each slot where a Pixie module is installed Parameter description Boot_Pattern is a bit mask used to control the boot pattern of Pixie modules Bit 0 Boot communication FPGA Bit 1 Boot signal processing FPGA Bit 2 Boot DSP Bit 3 Load DSP p
52. ng 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 delay is a quantity that the user will want to set In the PIXIE 4 Viewer it is called TraceDelay measured in microseconds and is available through the Settings tab The recommended setting for PafLength is 40 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved PafLength TriggerDelay TraceDelay 13 3ns 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 all filter ranges TriggerDelay PeakSep 1 2 FilterRange 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 13 3ns clock ticks after the in
53. ngs that may change in between runs UserChannel This function is called for every event and every PIXIE 4 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 UserQut 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 RUNTASK RUNTASK of the current run EOL lagging Energy filter low word E0H lagging Energy filter high word EIL leading Energy filter low word E1H leading Energy filter high word Your 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 2 to 6 in the user manual
54. obal variable arrays we also need to define three global name arrays System Prameter_ Names Module Parameter Names and Channel Parameter Names respectively Table 3 1 lists the names contained in each of these name arrays The order of placing these names into the name array is not important since the API uses search functions to locate each name at run time Table 3 1 Contents of Global Name Arrays Array Names System Parameter Names NUMBER_MODULES OFFLINE_ANALYSIS C_LIBRARY RELEASE C_LIBRARY_BUILD SLOT WAVE Module Parameter Names MODULE NUMBER MODULE CSRA MODULE_CSRB 7 7 MODULE FORMAT MAX EVENTS COINCIDENCE PATTERN ACTUAL COINCIDENCE WAIT MIN COINCIDENCE WAIT SYNCH_WAIT IN SYNCH RUN_TYPE FILTER RANGE BUFFER HEAD LENGTH EVENT HEAD LENGTH CHANNEL HEAD LENGTH OUTPUT BUFFER LENGTH NUMBER EVENTS RUN_TIME BOARD VERSION SERIAL NUMBER Channel Parameter Names CHANNEL_CSRA CHANNEL CSRB ENERGY_RISETIME E 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 INTEGRATOR LIVE_TIME INPUT _COUNT_ RATE FAST PEAKS 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 the PIXIE 4 modules 20 PIXIE 4 Programmer s Manual V1 41 XIA 2007
55. odules present in the system 3 Copy parameters from one module to others or extracts parameters from a settings file and applies to the selected modules Parameter description Values is an unsigned 16 bit integer array used for data transfer between the user interface and Pixie 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 Table 2 2 Different I O operations using function Pixie_Buffer_IO Type Direction Values T O Operation 0 0 DSP 1 0 variable values Write DSP I O aus 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 in the system 0 Values 0 source module Extract settings from a file and apply to number Values 1 source selected modules 3 channel number Values 2 1 copy extract pattern bit mask Copy settings from a source module to Values 3 Values 4 destination modules destination channel pattern 4 N A Values 0 address Values 1 Specify the location and number of w
56. on Required Files Option C source files C header files Library files boot h defs h globals h a dynamic link sharedfiles h utilities h PciApi h Lak library DIE POOR Stone PciRegs h Plx h PlxApi h 5 PIS DRIN or static library Deo e values PlxDefinitionsCheck h PlxError h Beno PlxTypes h Reg9054 h Besa ope boot h defs h globals h pixie gt uitst pe ace ess vas Ivor XOP di face gt utilities h PciApi h PciRegs h PIxApi lib 8 PR P Plx h PIxApi h PIxApi dll ada PlxDefinitionsCheck h PlxError h i PlxTypes h Reg9054 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 19 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved 3 Control PIXIE 4 Modules via CompactPCl 3 1 Initializing We describe here how to initialize PIXIE 4 modules in a PXI chassis using the functions described in Section 2 As an example we assume two PIXIE 4 modules resided in slot 3 and 4 respectively Users are also encouraged to read the sample C code shipped with the API 3 1 1 Initialize Global Variables As discussed in Section 2 we assume that three global variable arrays have been defined System_Parameter_Values Module _Parameter_ Values and Channel_Parameter_Values For these three gl
57. or is set to store output data in new files every N spills or seconds this function is called at the end of making the new files after the run has resumed It can be used to process output data automatically during these multi file runs However it will interfere with the 55 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved polling routine so the time to execute User_NewFileDuringRun should be less than the polling time Function User_StopRun This function is called at the end of the run By default it calls another function to duplicate the output data displayed in the standard Igor graphs and panels into a data folder called root results It can be used to process output data Function User_ChangeChannelModule This function is called when changing Module Number or Channel Number By default it calls a function to update the variables in the User Control panel Function User_ReadEvent This function is called when changing event number in list mode trace display or digital filter display By default it duplicates traces and list mode data into the results data folder Function User_TraceDataFile This function is called when changing the file name in list mode trace display 7 2 Igor User Panels The Igor user panels defined in the current version of the user code are listed below Window User_Control this is the main user control panel listing DSP input and output variables and showing seve
58. ords to be 16 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved length written into the data memory 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 1 Failure to set DACs after writing DSP parameters Reboot the module 2 Failure to program Fippi after writing DSP parameters Reboot the module 3 Failure to set DACs after loading DSP parameters Reboot the module 4 Failure to program Fippi after loading DSP parameters Reboot the module 5 Can t open settings file for loading Check the file name 6 Can t open settings file for reading Check the file name l Can t open settings file to extract settings Check the file name 8 Failure to set DACs after copying or extracting settings Reboot the module 9 Failure to program Fippi after copying or extracting settings Reboot the module 10 Invalid module number Check ModNum 11 Invalid I O direction Check direction 12 Invali
59. ral action buttons This panel can be modified to set user variables and control user procedures Window User_Version ctrIName This panels displays the version and variants of the user code UserVersion the version of the user function calls defined by XIA UserVariant the variant of the code written by the user USEROUT 0 the version of the DSP code written by the user 7 3 Igor User Variables The main Igor code defines the global variables and waves below for use in user procedures The user code can modify these values without interfering with the main code An exception is the UserVersion which should not be modified but used to ensure the user code is compatible with the main code NewDataFolder o root results the Igor data folder where results for user are stored 56 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved Variable G root results RunTime Variable G root results EventRate Variable G root results NumEvents Wave root results ChannelLiveTime Run Time from run statistics panel Event rate from run statistics panel Total number of events Channel live time Wave root results ChannelInputCountRate Channel input count rate Start time from run statistics panel Stop time run statistics panel String G root results StartTime String G root results StopTime Wave root results MCAch0 Wave root results MCAch1 Wave root results MCAch2 Wave root results MCAch3 Wave
60. ray containing the names to be downloaded U8 Name A string indicating the type of names file or variable names to be downloaded Description Use this function to download the file or variable names from the host user interface to the Pixie 4 API The API needs these file names so that it can read the Pixie hardware configurations from the files stored in the host computer and download these configurations to the Pixie The variable names are used by the API to obtain the indices of the DSP variables when the API 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 The API will know which type of names is being downloaded by checking the other parameter Name 1 ALL_FILES This indicates we are downloading boot files names In this case Names is a string array which has N BOOT FILES elements Currently N_BOOT FILES is defined as 7 The elements of Names are the names of communication FPGA files Revision B and Revision C respectively signal processing FPGA file DSP executable code binary file DSP I O parameter values file DSP code I O variable names file and DSP code memory variable names file All file names should contain the complete path name 2 SYSTEM This indicates we are downloading System Parameter Names System_Parameter Names are those global variables that are applicable to all
61. ription Error Handling 0x90 Success None 0x91 Failure to read out MCA section of external memory Reboot the module 0x92 Failure to write to MCA section of external memory Reboot the module 0x93 Failure to read out LM section of external memory Reboot the module 0x94 Failure to write to LM section of external memory Reboot the module 0x95 Invalid external memory I O request Check the run type Usage example S32 retval U16 RunType U32 dummy 2 U8 ModNum RunType 0x1100 start a new list mode run ModNum 0 retval Pixie Acquire Data RunType dummy ModNum if retval 0x10 Error handling wait until the run has ended RunType 0x4100 while Pixie Acquire Data RunType dummy ModNum Read out the list mode data from all Pixie modules and save to a file RunType 0x6100 13 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved retval Pixie Acquire Data RunType dummy C XIA Pixie4 PulseShape Listdata0001 bin ModNum if retval 0x60 Error handling Read out the histogram data from all Pixie modules and save to a file RunType 0x5100 retval Pixie Acquire Data RunType dummy C XIA Pixie4 MCA Histdata0001 bin ModNum if retval 0x50 Error handling 14 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights re
62. s time counter is 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 13 3ns GSLTTIMEA GSLTTIMEB 44 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved GSLTTIMEC Unused 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 with SYNCHWAIT 1 BUFHEADLEN At the beginning of each run the DSP writes a buffer header to the list mode data 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 list mode 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 EVENTHEADLEN is 3 but this value should not be hardcoded it should be read from the DSP to ens
63. s by inverting them immediately after entering the FPGA GFLT Set this bit if you want to validate or veto events using the PXI backplane 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 0 no later than an energy filter rise time after the signal arrival and must remain at logic 0 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 37 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Bit 8 Reserved Set to 0 Bit 9 Reserved Bit 10 Compute constant fraction timing This pulse shape 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 13 3 ns Time zero is the start of the waveform Bit 11 13 Reserved Bit 14 Estimate energy if channel not hit If set the DSP reads out energy filter values and computes the pulse height for a channel that is not hit for example when read always in group trigger mode If not set the energy will be reported as zero if the channel is not hit Bit 15 Reserved CHANCSRB Control and status register B Bit 0 If set call user written DSP code Bit 1 If set all words in the channel header except Ndata trigtime and energy will be overwritten with the contents o
64. s 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 Reprogramming the DACs is required to make effective changes in the values of the variables GAINDAC 0 3 TRACKDAC 0 3 Control Task 1 Connect inputs Close the input relay to connect the PIXIE electronics to the input connector Control Task 2 Disconnect inputs Open the input relay to disconnect the PIXIE 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 list mode buffer At the end of the task the list mode 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 0 the last entry is for a DAC value of 65504 In betwe
65. served Pixie_Set_Current_ModChan Syntax S32 Pixie Set Current ModChan U8 Module Module number to be set U8 Channel Channel number to be set Description Use this function to set the current module number and channel number Parameter description Module specifies the current module to be set Module should be in the range of 0 to MAX NUMBER OF MODULES currently MAX NUMBER OF MODULES is set to 7 Channel specifies the current channel to be set Channel should be in the range of 0 to NUMBER OF CHANNELS 1 currently NUMBER OF CHANNELS is set to 4 Return values Value Description Error Handling 0 Success None 1 Invalid module number Check Module 2 Invalid channel number Check Channel Usage example Set current module to 1 and current channel to 3 Pixie Set Current ModChan 1 3 15 PIXIE 4 Programmer s Manual V1 41 O XIA 2007 All rights reserved Pixie_Buffer_lO Syntax S32 Pixie Buffer IO An unsigned 16 bit integer array containing the data to be transferred U l6 Values U8 U8 U8 U8 Description Use this function to type Data transfer type direction Data transfer direction file name File name ModNum Module number 1 Download or upload DSP parameters between the user interface and the Pixie modules 2 Save DSP parameters into a settings file or load DSP parameters from a settings file and applies to all m
66. 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 PIXIE 4 API So instead of directly setting DSP variables users only need to set the values of those global variables defined in Table 3 1 The API 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 API will first convert these DSP values into the global variable values The code shown below is an example of setting DSP variables through the API An Example Code Illustrating How to Set DSP Variables through the API S32 retval U8 direction modnum channum direction 0 download modnum 0 Module 0 channum 0 Channel 0 set COINCIDENCE PATTERN to OxFFFF Module Parameter Values COINCIDENCE PATTERN Index OXxFFFF download COINCIDENCE PATTERN to the DSP retval Pixie User Par IO Module Parameter Values COINCIDENCE PATTERN MODULE direction modnum channum if retval lt 0 Error handling set ENERGY RISETIME to 6 0 ys Channel Parameter Values ENERGY RISETIME Index 6 0
67. st that user code use this information to create a name 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 PIXIE 4 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 PIXIE Viewer 4 1 Module parameters MODNUM Logical number of the module This number will be written into the header of the list mode buffer to aid offline event reconstruction MODCSRA The Module Control and Status Register A Bit 0 If set timestamps are latched by local triggers not by the last group trigger This preserves trigger timing information for runs without waveform acquisition Bit 1 If set DSP acquires 32 data buffers in each list mode run and stores the data in external memory If not set only one buffer is acquired and the data is kept in local memory Bit 2 Bits 2 and 15 control trigger distribution over the backplane If neither bit 2 or bit 15 are set triggers are distributed only between channels of this module Otherwise triggers are distributed as follows 30 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit
68. tem Parameter Values Finally function Pixie_Boot_System should be called to boot the modules The following code is an example showing how to boot the PIXIE 4 modules using the API functions An Example Code Illustrating How to Boot PIXIE 4 Modules S32 retval U8 direction modnum channum initialize system parameter values System Parameter Values NUMBER MODULES Index 2 System Parameter Values OFFLINE ANALYSIS Index O System Parameter Values SLOT WAVE Index 3 System Parameter Values SLOT WAVE Index 1 4 retval Pixi _Hand_Down_Names System Parameter Names SYSTEM if retval lt 0 Error handling retval Pixie Hand Down Names Module Parameter Names MODULE if retval lt 0 21 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Error handling retval Pixi _Hand Down Names Channel Parameter Names CHANNEL if retval lt 0 Error handling retval Pixie Hand Down Names All Files ALL FILES if retval lt 0 Error handling direction 0 download modnum 0 Module 0 channum 0 Channel 0 retval Pixie User Par IO System Parameter Values NUMBER MODULES SYSTEM direction modnum channum if retval lt 0 Error handling retval Pixie User Par IO System Parameter Values OFFLINE ANALYSIS SYSTEM
69. ternal event trigger The default value written by the PIXIE module should not be changed by the user FTPWIDTH Unused 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 taken depends on FIFOlength which is 1024 If TraceLength lt FIFOlength the DSP will read from the FIFO In that case individual samples are 13 3 ns apart If FIFOlength lt TraceLength the PIXIE 4 code will force the TraceLength to be equal to FIFOlength XWAIT Extra wait states This parameter controls how many extra clock cycles the DSP waits when reading waveform data in real time rather than out of a FIFO memory This occurs when acquiring data in list mode and asking for trace lengths longer than FIFOlength The time between recorded samples is AT 3 XWAIT 13 3ns XWAIT is used differently when acquiring untriggered traces in a control run with ControlTask 4 In this case the time between recorded samples is 41 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved AT 4 13 3ns if XWAIT lt 4 XWAIT 13 3ns 114 lt XWAIT lt 12 3 XWAIT 13 3ns if XWAIT gt 13 XWAIT has to be multiple of 5 The fol
70. 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 When a PIXIE 4 is operated on its own the user can request that certain coincidence anticoincidence patterns are found for the event to be accepted With four channels 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 Pixie 4 to accept any hit pattern as valid In the PIXIE 4 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 34 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved Pattern entry COINCWAIT Duration of the coincidence time window in clock ticks each clock tick spans 13 3 ns The actual coincidence window is 26 6 ns 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 ca
71. ticks INTEGRATOR This variable controls the energy reconstruction in the DSP BLCUT INTEGRATOR 0 normal trapezoidal filtering INTEGRATOR 1 use gap sum only good for scintillator signals INTEGRATOR 2 ignore gap sum pulse height leading sum trailing sum good for step like pulses INTEGRATOR 3 4 5 same as 1 but multiply energy by 2 4 or8 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 42 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved 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 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 BASELINEPERCENT This variable sets the DC offset level in terms of the percentage XAVG of the ADC range Only used in Controltask 4 for reading untriggered traces XAVG stores the weight in the geometric weight averaging scheme to remove higher frequency signal and noise components The value is calculated as
72. tionally this manual also includes instructions on how to write User DSP code 2 PIXIE 4 API The PIXIE 4 API consists of a set of C functions for building various coincidence data acquisition applications It can be used to configure Pixie 4 modules make MCA or list mode runs and retrieve data from the Pixie modules The API can be compiled as a WaveMetrics Igor XOP file which is currently used by the Pixie 4 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 Pixie 4 is given below and the usage of these functions is mentioned wherever appropriate At first the PIXIE 4 API needs to be initialized This is a process in which the names of system configuration files and variables are downloaded to the API The function Pixie_Hand_Down_Names is used to achieve this The second step is to boot the Pixie modules It involves initializing each PXI slot where a Pixie module is installed 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 DACs All this has been encapsulated in a single function Pixie_Boot_System Now the instrument is ready for data acquisition The function used for this purpose is Pixie
73. trol 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 the master channel to ensure equal time of arrivals for the fast trigger signal which is used to halt the FIFOs Note To distribute group triggers between modules bit 2 in the variable MODCSRA has to be set as well 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 marked 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 slope The trigger filter FPGA can only handle positive signals The PIXIE handles negative signal
74. ts 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 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 Level 1 buffer is not used in this run type Nine words of results including time of arrival energy XIA pulse shape analysis user pulse shape analysis etc are written into the I O buffer for each channel RunTask 513 0x201 requests a compressed fast list mode run without trace capture Both Level 1 buffer and I O buffer are used in this RunTask Nine words of results including time of arrival energy XIA pulse shape analysis user pulse shape analysis etc are written into the I O buffer for each channel 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 33 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved words of results time of arrival energy XIA pulse s
75. ure 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 is the sum of EventHeadLen and the ChannelHeadLengths plus the TraceLengths for all channels marked as good i 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 13 3us 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 list mode data buffer which is 8192 words long But there is not enough room in the level 1 buffer which contains only 2048 words 45 PIXIE 4 Programmer s Manual V1 41 XIA 2007 All rights reserved 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 should
76. 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 PIXIE 4 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 PIXIE 4 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 activated 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 ex

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