Peak&Hold Current Shape generated by TriCore
Contents
1. Figure 3 Coil driven current controlled high pressure Injector Application Note 6 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Requirements for Direct Injection Applications 2 2 Possible System Solutions The implementation for generating a Peak amp Hold current shape can be solved by using different system solution configurations In principle the following descriptions presents two different system solutions 1 All necessary current control algorithms are implemented in a Peak amp Hold Application Specific Integrated Circuit ASIC 2 An intelligent peripheral module the General Purpose Timer Array GPTA of the TriCore Microcontroller TC1775 is used for the control algorithm and the diagnosis of a Peak amp Hold coil driven current controlled injector This application note mainly focuses to the second approach The generation of the Peak amp Hold current waveform together with the TC1775 Application Note 7 2 1 2002 09 Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Requirements for Direct Injection Applications 2 2 1 Generation of Peak amp Hold Current Shape with Application Specific IC ASIC One of the possible system solutions is to use an external ASIC to control the Peak amp Hold current shape A Quad Direct Injection Switch is intended to be used for the generation of Peak amp Hold curren2. For the generation of a Peak amp Hold current shape the usage of the TC1775 and its peripheral module GPTA shows a cost efficient way to solve the application requirements and therefore to save system cost on customer s side Application Note 34 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Appendix 7 Appendix 7 1 Related Documentation and SW Package 701775 User s Manual V2 0 TriBoard TC1775B Hardware Manual V1 0 SW package peak amp hold exe self extracting generated with Tasking TriCore toolchain V1 1R2 Terminal Program Multi threaded TTY sample MTTTY exe included within peak amp hold exe 7 2 List of Figures Figure 1 Peak amp Hold Current Shape ecceeceeeeneeseneeceneeeeeeeseaeeseaeeseaeeseneeseeeeneess 4 Figure 2 Peak amp Hold Electronic Circuit Block Diagram 0 cee eee eee 5 Figure 3 Coil driven current controlled high pressure Injector cceeeeeeeeeeeee 6 Figure 4 Direct Injector Drive for Peak amp Hold together with ASIC eee 8 Figure 5 Possible generated Waveform for the usage of an ASIC sasse 9 Figure 6 Block Diagram 1 for Parallel High Side Switch Configuration 10 Figure 7 Block Diagram 2 for Serial High Side Switch Configuration 00 11 Figure 8 Block Diagram 3 for Low Side Switch Current PWM s es 12 Figure 9 Block Diagram of GPTA peripheral eccecceeeeeeeseeeeeeeretee
3. LTC27 Reset Timer_2 LTC28 Period Time of SIM_SCOUT LTC29 Compare with Timer_2 Reset SIM_SCOUT LTC30 Compare with Timer_2 Set SIM_SCOUT O GPTA30 P9 14 SIM_SCOUT lO Test_Pin_1 Reset at Interrupt Entry Set at INT_BENCH_1 O GPTA47 Interrupt End of GPTA P10 15 lO Test_Pin_2 Reset at Interrupt Entry Set at INT_BENCH_2 0O GPTA46 Interrupt End of ASCO P10 14 lO Test_Pin_3 Reset at Interrupt Entry Set at INT_BENCH_3 0O GPTA45 Interrupt End of GTO overflow P10 13 Table 1 Used GPTA Resources Application Note 32 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Software Application Example Note LTC30 output has to be connected to LTC7 input in simulated mode to get an output signal at GPTA9 P8 9 GTC15 output is the inverted GTCO output used for test purposes only 10 Test_Pin2 3 are not used and not activated in the SW Example 5 3 Connection to PC Terminal Program The TriBoard for TC1775 can be connected via a standard RS232 serial cable to the PC The Peak amp Hold SW application example visualizes the diagnostic capability for the Peak amp Hold current shape The period time for the peak current control loop and the period for the hold current control loop are displayed by receiving and displaying serial data with help of the program Multi threaded TTY sample MTTTY exe which is a part of the delivery package of the SW example for Peak amp Hol
4. PCP Control Status Register PCP_CS and PCP Interrupt Control Register PCP_ICR has to be initialized what is done in the main c The PCP can be used in different modes and with different context sizes In this application the channel resume mode and full context 8 registers for each channel is chosen In channel resume mode the user can arbitrarily determine the address at which the channel program will be started the next time it is invoked For this purpose the PC is saved and restored as part of the context of a PCP channel The interrupts call a particular part of the PCP program a so called PCP channel The interrupt priority corresponds to the channel number So an interrupt with priority 7 would call the PCP channel 7 if it is mapped to the PCP In the Service Control Register it can be determined by the bitfield TOS if the service is be done either by the CPU or PCP mod_SRC Service Request Control Register Reset Value 0000 0000 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 SET CER SRR SRE TOS 0 SRPN w w rh rw rw T t t r 4 1 2 The PCP Program File The PCP has its own instruction set so a special assembler is necessary In the Tasking toolchain the PCP compiler ASPCP is integrated which allows to handle the PCP file with the EDE This PCP file has to follow a certain structure so that it can be assembled Application
5. Note 23 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Partitioning 4 1 2 1 PCP Sections The PCP file has to contain the sections CODE and DATA which correspond to the PCP Code memory program respectively to the PCP Parameter memory context and data Following an example for the CODE and DATA section definition Sections Definitions PRAM Code definition starting at address 0x02 SDECL pcp code CODE INIT AT 0x2 PCP Rom memory PCODE SECT pcp code Write into PCP Code Section SDECL pcp context DATA INIT AT 0x0 PCP Ram memory PRAM SECT pcp context Write into PCP RAM Section When using the PCP without a debugger please assure that a copy of the Parameter RAM PRAM and the Code RAM PCODE of the PCP is done in the ROM area During the cstart asm execution these memory portions will be copied automatically into the corresponding PCP memory SRAM locations after power on reset For the Tasking Tricore Toolchain this can be achived by the keyword INIT beginning with V1 1R2 4 1 2 2 Start Address of a Channel Program As mentioned above in channel resume mode the start address for a certain PCP channel is determined by the PC Program Counter which is stored in the context This PC is updated when the channel is left But when the channel is called for the first time the PC is not automatically set It is possible to initialize the register R7 in
6. SDECL pcp data DATA INIT AT 0x080 PCP Ram memory PRAM SECT pcp data Write into PCP RAM Section pEN_LOW_ON_MAX_HOLD word EN_LOW_ON_MAX_HOLD pEN_LOW_OFF_HOLD word EN_LOW_OFF_HOLD pSCOUT_PERIOD 2 word SCOUT_PERIOD 2 It is necessary to declare the constants and variables defined in the C files with the extern directive so the assembler can access them External Symbol Declaration extern EN_LOW_ON_MAX HOLD to pass addresses of constants extern EN_LOW_OFF_HOLD extern SCOUT_PERIOD_2 extern pulse_level_cyl_l to pass addresses of variables extern diagnosis_hold extern diagnosis_peak extern begin_injection Note The prefix _PCP_ for global symbols is not used in this project The Tasking EDE uses this prefix on default it can be modified in EDE PCP Assembler Options Project Options Misc Application Note 27 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Partitioning 4 1 3 PCP Debugging and Test To debug the PCP some requirements have to be observed like full context has to be used or a PCP error interrupt routine has to be available Because this requirements depends mainly on the used tools please refer to the according tools manual Application Note 28 2 1 2002 09 Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Software Application Example 5 Software Application Example The de
7. of the inductance Application Note 10 2 1 2002 09 eo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Requirements for Direct Injection Applications The current is monitored with a shunt resistor An external comperator evaluates the occuring voltage on the resistor The measured value is compared to a given programmable threshold either peak value or hold value The GPTA module is used to capture the signal SCOUT at the output of the comperator 2 2 2 2 Serial High Side Switch Configuration Y 80V boost HS_Switch_2 EN_80 vV 12V HS_Switch_1 EN_12 AUDO TC1775 ee ee eee eee HS_Switch_5 AFWH HS_Switch_1 EN_12 HS_Switch_2 EN_80 Injector j Injector CYL_1 CYL_4 LS_Switch_1 b CYL_SEL_1 X LS_Switch_4 b CYL_SEL_4 ec a ee ee dl ne 4 ka Lassan Vr Threshold Value Block Diagram for Peak and Hold Injection Demonstrator for Diesel Common Rail Topologie 1 Figure 7 Block Diagram 2 for Serial High Side Switch Configuration In the configuration shown in Figure 7 two serial high side switches are used to generate the Peak amp Hold current waveform applied to the coil of a selected injector The difference to the previous parallel high side switch configuration is that the current control loop can be achieved by using only one high side switch EN_12 for the PWM The high side switch EN_80 is only s
8. project otherwise the C files might not be processed by the preprocessor In the Tasking Compiler the option zTC112_DEFECTS in EDE C Compiler Options Project Options Misc must be used to force the compiler to introduce workarounds for the TC1775B erratas Application Note 31 2 1 2002 09 d Infineon technologies AP32029 Peak amp Hold Current Shape generated by TriCore 5 2 Software Application Example Used GPTA Resources for the Peak amp Hold Generation In the following Table 1 the used resources for the generation of the Peak amp Hold current waveform and the corresponding mapped I O ports refering to the naming convention of the TriBoard for TC1775 can be found Used GPTA Cells Description of the Function Signal Name I O TC1775 AUDO1 and Test Pins for Expansion Board 4 Cell LTC Model at connect X804 GTO Free running Timer GTCO Capture after Compare CYL_SEL_ 1 0 GPTA0 P8 0 GTC3 Compare Mode EN_80 0 GPTA3 P8 3 GTC12 Compare Mode SWTL GPTA12 P8 12 GTC15 Capture after Compare Test CYL_SEL_1 O GPTA15 P8 15 Cell inverted GTCO output LTC6 Reset Timer_1 LTC7 Capture SCOUT Reset SCOUT GPTA7 P8 7 Timer_1 Reset EN_12 LTC8 Compare with Timer_1 Set EN_LOW if specified Off Time occured OFF Time EN_LOW_OFF_TIME LTC9 Compare with Timer_1 Reset EN LOW O GPTAQ P8 9 EN_LOW if max value occured Maximum ON Time EN_LOW_MAX_ON_TIME
9. 5 00 Figure 5 Possible generated Waveform for the usage of an ASIC Application Note 9 2 1 2002 09 oe Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Requirements for Direct Injection Applications 2 2 2 Generation of Peak amp Hold Current Shape with GPTA Peripheral Module A complete different way for the generation of the Peak amp Hold current shape is the usage of the 32 bit TriCore derivative TC1775 All used control signals can be easily generated by using the embedded peripheral module GPTA In the following chapter there will be given an overview of three different circuit configurations which could be used in principle to realize a direct injection Peak amp Hold application 2 2 2 1 Parallel High Side Switch Configuration O Vs 80V HS_Switch_2 EN_80 HS_Switch_1 EN_12 AUDO TC1775 TriCore HS_Switch_5 AFWH HS_Switch_1 EN_12 HS_Switch_2 EN_80 Injector Injector CYL_4 LS_Switch_1 b CYL_SEL_1 gt LS_Switch_4 p CYL_SEL_3 CYL_SEL_4 _ I I I I 1 H Injector 1 I I I I I I I 1 J Threshold pa Value Figure 6 Block Diagram 1 for Parallel High Side Switch Configuration Both high side switches are used to drive the PWM current through the coil of a selected injector Optional free wheeling diodes can be used dependant on the decay time
10. Application Note V 2 1 Sept 2002 AP32029 TC1775 Peak amp Hold Current Shape generated by TriCore derivative TC1775 Microcontrollers Never stop thinking TC1775 Revision History 2002 09 2 1 Previous Version V2 0 2001 09 Page Subjects major changes since last revision All Adjusted to conform with Infineon template several PCP functionality included Controller Area Network CAN Licence of Robert Bosch GmbH We Listen to Your Comments Any information within this document that you feel is wrong unclear or missing at all Your feedback will help us to continuously improve the quality of this document Please send your proposal including a reference to this document to mcdocu comments infineon com D lt oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Introduction Table of Contents Page 1 IMTOGUGUOME sisca paagiaeead ties 4 2 System Requirements for Direct Injection Applications ceeeeeeeeeee 5 2 1 System OVEIVICW 00 ceeeeeecceeeeeeeeteaeeteeeeseaeeeaeetsaeeeeaeeseaeeseaeessaeeseaeeseeeeneeetens 2 2 Possible System Solutions 2 2 1 Generation of Peak amp Hold Current Shape with Application Specific IC ASIC E E hive cae A died E de eee eons 8 2 2 2 Generation of Peak amp Hold Current Shape with GPTA Peripheral MOGUIG eier eae e E a tee ceen deteead eudpstae caees tnavbectle sees 10 2 2 2 1 Para
11. C 02 LTG08 LTE 04 SN LN A N NS NY a N Ni SI y Y NRE NNNNA NIN NNK Global Timer Cell Array Figure 9 Block Diagram of GPTA peripheral Local Timer Cell Array LT 62 LTC 63 N jA N N N NO Ww S SN aa DQ YOOX TN N The GPTA unit consists of the following Sub Modules Clock Generation Unit FPC Filter and Prescaler Cell PDL Phase Discrimination Logic DCM Duty cycle Measurement Cell PLL Phase Locked Loop Signal Generation Unit GTx Global Timer 0 and 1 GTC Global Timer Cell LTC Local timer Cell Application Note 13 2 1 2002 09 _ Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA The GPTA Module is intended to be used for the following signal preconditioning counting capture compare and PWM functionalities Flexible Clock Generation filtering and high resolution signal acquisition Digital PLL Universal Building Blocks can be combined to form the required timer structure LEGO approach Global Timer Cell Array 32 cells 24 bit wide GTC operates relative to global timers array mainly used for input signal capturing and output signal generation Local Timer Cell Array 64 cells 16 bit wide LTC will operate relative to local timers mainly used for PWM signal generation and input signal measuremen
12. CPU or PCP to control the current shape generation When the PCP is used the CPU is not needed at runtime to control the GPTA The startup initialization of the GPTA is always done by the CPU because it makes no sense to do this with the PCP For that a copy of the PCP initialization program would have to be held in the CPU memory copied to PCP Code RAM and than executed It s faster to do this by the CPU even less PCP memory has to be used At runtime the current shape generation is completely controlled with three interrupts This interrupts has to be mapped either to the CPU or PCP 4 1 The Peripheral Control Processor PCP As already described in chapter 3 the PCP has its own Code and Data RAM This chapter gives some hints how the PCP has to be handled i p a Fi is PEP mamin Arhiraiion Hum CPU inbecrupt Arion Burt icimi Figure 16 PCP Block Diagram Additional information can be found in the User s Manual and in the application note AP3225 The Peripheral Control Processor PCP or a smart way to service an interrupt request Application Note 22 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Partitioning 4 1 1 PCP Initialization The PCP has first to be initialized before program code can be executed This initialization can also be done using DAVE the Digital Application Engineer available from Infineon Mainly the two registers
13. T_PERIOD_2_us 50 period 2 of input stimuli SCOUT define SCOUT_LOW_EDGE_1_us 4 falling edge of input stimuli SCOUT within PERIOD1 of SCOUT define SCOUT_HIGH_EDGE_1_us 6 rising edge of input stimuli SCOUT within PERIOD1 of SCOUT valid beginning with falling edge of EN_80 define SCOUT_LOW_EDGE_2_us 0 falling edge of input stimuli SCOUT within PERIOD2 of SCOUT define SCOUT_HIGH_EDGE_2_us 25 rising edge of input stimuli SCOUT within PERIOD2 of SCOUT valid beginning with the first falling edge of SCOUT after switch off EN80 define SCOUT_LOW_EDGE_3_us 9 falling edge of input stimuli SCOUT within PERIOD2 of SCOUT define SCOUT_HIGH_EDGE_3 us 1i rising edge of input stimuli SCOUT within PERIOD2 of SCOUT To select if the Peak amp Hold current shape is generated under CPU or PCP control the switch PCP_INT in EDE C Compiler Options Project Options Preprocessing can be used The PCP is used to control the signal when PCP_INT is defined If the software shall be programmed to external flash it is necessary to include the appropriate initialization which is normally done by the debugger by including the cstart asm There are two different files available one for Tasking V1 1R2 and one for V1 3R1 Further information about flash programming can be found in the readme txt included in the zip file To get a modification of a switch active it is necessary to rebuild the
14. _80 EN_LOW SCOUT CYL_SEL_x amp Reset_Timer_1 Figure 14 Complete Control Signals generated by the GPTA peripheral Application Note 19 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA Figure 14 summarizes all relevant interrupt based reconfigure interactions which have to be executed by using the TriCore CPU or the Peripheral Control Processor PCP 1st Interrupt generated at the beginning of the Injection Pulse rising edge of CYL_SEL_x CYL_SEL_x pulse length is configured SWTL signal is configured to Peak_Time and interrupt action is prepared when rising edge occurs EN_80 signal is configured to Peak_Time length EN_LOW signal is switched on Interrupt action prepared if first falling edge is detected at input SCOUT 2nd Interrupt generated at the first falling edge of input signal SCOUT EN_LOW switched off simultaneously switched off with falling edge of SCOUT HW 4 cell LTC current control model configured for autonomous work Reset and Start Reset_Timer_1 3rd Interrupt generated with rising edge of signal SWTL SWTL Hold_Time length configured EN_LOW signal switched off Interrupt action prepared if rising edge occurs at signal SCOUT 4th Interrupt generated with rising edge of signal SCOUT EN_LOW switched on 4 cell LTC current control mod
15. d The following message will be shown by the PC Terminal Output Hello World I am the TriBoard for TC1775 AUDO1 developed at INFINEON Technologies AG in Munich Have fun working with me The TC1775 is clocked with 40000000 Hz time 00h 03min 45sec captured diag_peak 13525 ns diag_hold 10425 ns Explanations time displays the time in hours minutes seconds which has been occurred since the start of the program captured diag peak period in ns for the current control loop while Peak is active diag hold period in ns for the current control loop while Hold is active Application Note 33 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Conclusion 6 Conclusion This application note outlined the flexibility and the powerful capabilities of the TC1775 and its peripheral module GPTA in conjunction with the PCP With the help of this new architecture approach where the application SW layer can be clearly separated from the HW dependent low level SW layer the demands for state of the art SW development can be fulfilled The full HW driven closed loop current control algorithm is able to achieve theoretically switching frequencies up to half the CPU clock speed f max for TC1775 is 40 MHz Therefore this fast current control algorithm also can easily be adapted for piezo hydraulic high pressure injectors which needs current control frequencies above 100 kHz
16. echnologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA The generation of the basic control signals CYL_SEL_x SWTL and EN_80 can be achieved by the following configuration scheme The customers application SW generates a rising edge begin of injection pulse of the CYL_SEL_x output signal and simultaneously an interrupt is generated which is executed by using the PCP or CPU This interrupt routine reconfigures the GT cells for the signals CYL_SEL_x SWTL and EN_80 as follows CYL_SEL_x GT cell is reconfigured to the new compare value end of injection pulse SWTL is reconfigured to switch the threshold level from peak current to hold current after the Peak_Time has expired and simultaneously an interrupt will be generated when the rising edge of SWTL occurs This second interrupt reconfigures the SWTL GT cell to the end of injection pulse EN_80 GT cell is reconfigured to the length of Peak_Time 3 2 Usage of Local Timer Cell Array The closed loop algorithm for controlling the peak and hold currents for the Peak amp Hold current shape is managed by using a four cell Local Timer Cell Array LTC model Captured Value Dead can be used for Diagnosis o Pra i EN_LOW_MAX_OFF_TIME Reset_Timer_1 ALON OFF_TIME Local Timer Cells Threshold Injector Current EN_LOW_Output Figure 13 C
17. eeeeeeeneeeeaes 13 Figure 10 101775 System Partitioning eceeeeceeeeeeeeeeeeeeeeeeeeeeseeeseaeeeeteeeeaeees 14 Figure 11 Realization of Injector Pulse together with GTO 1 and GTCs 15 Figure 12 Injection Pulse Generation with GT GTC eee eee tee tee eeeteeeeees 16 Figure 13 Current Control by using a 4 Cell LTC Model ceecceseeeeeeeteteneeeeeeees 17 Figure 14 Complete Control Signals generated by the GPTA peripheral 19 Figure 15 Measured Waveform for Generation of Peak amp Hold Current Shape 21 Figure 16 PCP Block Diagraim eeceeeececeseeeeeeeceneeeeneeeeaeeseeeeseaeeeneeeseneeseeeseaeesenees 22 Figure 17 Context Storage in PRAM ccceeccecceeeeeeeeeneeeeeeeteaeeeeaeeseaeeeeeeeseeeeaeees 26 Figure 18 Simulated Waveform for Generation of Peak amp Hold Current Shape 29 7 3 List of Tables Table 1 Used GPTA RESOUICES ccccccccccccccccceceeecececeeeeceeeeeaeeneueueueuaueueuneeeenenennanes 32 Application Note 35 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore 7 4 TriCore AUDO PCP GPTA GTCA LTCA ASIC SW HW PWM HSS Appendix Abbreviations TriCore is the first single core 32 bit microcontroller DSP architecture optimized for real time embedded systems TriCore unifies the best of 3 worlds real time capabilities of microcontrollers computational pr
18. el configured for autonomous work Reset_Timer_1 reseted and restarted 5th Interrupt generated at the end of the injection pulse falling edge of CYC_SEL_x EN_LOW switched off Reset_Timer_1 switched off Application Note 20 2 1 2002 09 _ Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA In the following Figure 15 the measured Peak amp Hold current shape by using the delivered application SW for this application note can be found Slop it T SCOUT m sb Interrupt 4b c Activity 1 2 34 5 i j Injector t l UHHH Current ppa Chi 500w Ona 3 004 Mouse Chis 7 5930 WV Oa 500 MO so0ac io Mar 2000 4 000 W785 Figure 15 Measured Waveform for Generation of Peak amp Hold Current Shape In contrary to the description of Figure 14 three more interrupts than described 2b and 4b c are generated These interrupts have been added to the Peak amp Hold application SW example for diagnosis purposes The peak current in this example is about 13A and the hold current about 5A The approximate CPU PCP load in this example is about 2 for a injector pulse length of 900 us Application Note 21 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Partitioning 4 System Partitioning This application offers the possibility to use either the
19. eo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA This application note mainly focuses on the generation of the Peak amp Hold control signals within the time domain Therefore the delivered SW demonstrator example only uses GTO mapped to the time domain as a free running timer Taking advantage of the flexible timer structure of GPTA module it is sufficient to allocate one separate GTC for each Injector each cylinder of the engine Additionally two further control signals EN_80 Enable 80V and SWTL Switch Threshold has to be generated EN_80 determines the length of the high voltage switch on time Peak_Time and SWTL is used to switch between the externally used comparison current level thresholds for instance 12A for the Peak_Time and 5A for the Hold_Time Each of these signals need only one GT cell and can be used for all four cylinders of the combustion engine when no overlapping phases between the injection pulses are required Otherwise two more GT cells for the generation of the signals EN_80 and SWTL has to be allocated Peak_Threshold Injector Current Hold_Threshold Global Timer Time Domain Global Timer Cells CYL SEL SWTL EN_80 Global Timer free running Figure 12 Injection Pulse Generation with GT GTC Application Note 16 2 1 2002 09 oo Infineon AP32029 t
20. es Figure 1 outlines a typical Peak amp Hold Current Waveform for an high pressure injector Peak_Threshold Injector Current Hold_Threshold T2 Hold Figure 1 Peak amp Hold Current Shape During Peak_Time T1 a high voltage approx 80V is applied to the injector coil and the current level is controlled at current level Peak_Threshold During Hold_Time T2 the normal automotive board voltage 12V is applied to the injector coil and the current level is controlled at current level Hold_Threshold Main part of this application note will be the detailed description of the generation of a Peak amp Hold Current Shape together with a closed loop current control algorithm by using the TriCore derivative TC1775 This algorithm and the corresponding control signals are generated by using the embedded General Purpose Timer Array GPTA peripheral within the TC1775 controlled either by the CPU or Peripheral Control Processor PCP Application Note 4 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Requirements for Direct Injection Applications 2 System Requirements for Direct Injection Applications The following chapter gives a basic introduction into a state of the art high pressure diesel direct injection system with coil driven injectors Further different approaches to fulfill the direct injection requirement
21. livered SW package can be used to build up a functional demonstrator driving real HW by using block diagram 3 from Figure 8 Additionally the demonstrator SW can be taken to generate the simulated control waveforms by using a simulated SCOUT signal This simulated SCOUT signal is generated by using extra Local Timer LTC 27 30 within the GPTA The output of the simulated SCOUT signal has to be connected externally to the 4 cell local timer current control model In the following Figure 18 the simulated Peak amp Hold injector PWM can be found Stop A S 10 w 4 70 EN 80 A 300p5 iain 2 OOS WH SCOUT W simulated pa maania ja ee s acm aran Interrupt i Activity NIH PWM a cin 1 3 00 Che 5 00 v M ioii A Chi s 2 80 Chie 5 00 W Che 5 00 Y T Map 2009 4 600 5 LF 13514 Figure 18 Simulated Waveform for Generation of Peak amp Hold Current Shape This SW demonsirator example was developed by using the TriCore Tasking Toolchain V1 1R2 V1 3R1 and the evaluation PCB TriBoard for TC1775 Application Note 29 2 1 2002 09 Infineon technologies AP32029 Peak amp Hold Current Shape generated by TriCore Software Application Example 5 1 Overview of configurable Parameters In the following paragraph the constant definitions for the generation of the Peak amp Hold waveform can be found in the SW package located in file GPTA C The initialization
22. llel High Side Switch Configuration ccccccceeeeeeeeeeeeeeeeeee 10 2 2 2 2 Serial High Side Switch Configuration 0 ccceceeeeeeeeeeeeeseeeeeeeeeee 11 2 2 2 3 Low Side Switch Current PWM ceseeeeeeseneeeeeeeteeeseeeeteeeeeaeeeeas 12 3 Closed Loop Current Control together with GPTA eeeceeeeeeeteeeeeeeeeees 13 3 1 Usage of Global Timer Cell Array sesseesseeeseesreesreerrenesirsrnsererrnneenerenent 15 3 2 Usage of Local Timer Cell Array cceccceeesceseneeeeeeeeeneeseaeeeeeeeeeeeseneeeneeeeeea 17 3 3 Overview about the complete generated Waveforms c esceeceeeteeenees 19 4 System Partitioning csaten iaei eane E TEE aa aie 22 4 1 The Peripheral Control Processor PCP cesceeeseeseseeseeeeeeeeeeeneeeeeeeeeaees 22 4 1 1 PGP ritthaliZeatio nis 2h c552casde cans eagushedesdenetb ches lees dceetuheesace eneenceesetestucineaadad 23 4 1 2 The PCP Program Fil cceeeccessseeeseeesseeeeseeeseaeeeseeeseaeessaeessaeeenatens 23 4 1 2 1 POP SOCUONS ortae aeaa eaa Eaa EA EEA 24 4 1 2 2 Start Address of a Channel Program c cceesceeeeeeseneeeeeeeeeneeeeeeeeeee 24 4 1 2 3 PCP Comtex t oriei aceno riene a aaarnas i ei aeaee ae 25 4 1 2 4 Variables and Constants in PCP Parameter RAM 27 4 1 3 PCP Debugging and TeSt ceeeceseseeceseeeeseeseeeteaeeeeaeeseaeeesaeessaeenaaes 28 5 Software Application Example ccccceccceeeeeseeeeeeeeeeeeeseeeeseneeseeeseeeeeneees 29 5 1 O
23. mp Hold Current Shape generated by TriCore System Partitioning fei Mii dkms in Sen gar it mond ice Figure 17 Context Storage in PRAM The context of the channels has to be initialized in the section DATA at address 0x00 space 32 Chi word word word word word word word word 0x00020340 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 R7 channel enable set DPTR 3 Channel 0 mustn t be used so no context for this channel is necessary Application Note 26 BC 2 1 2002 09 2 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Partitioning 4 1 2 4 Variables and Constants in PCP Parameter RAM The PCP Parameter RAM PRAM at local address zero 0 is always implicitly used for the context save areas of the channel programs the remaining area can be used for channel specific or general data storage A programmable 8 bit data pointer DPTR concatenated with a 6 bit offset is provided for arbitrary access to the PRAM Every channel has its own data pointer DPTR which is very much like a segment register It is located in register R7 and has to be initialized accordingly This DPTR points to a 64 word base address which has to be higher then the last channel context It is recommended to define an extra section for the data PRAM data definition starting at address 0x80 PRAM Datapage 2
24. of the injection frame signals CYL_SELx SWTL and EN_80 define INJ_PULSE_ms 0 9 high level length of CYL SEL x define IDLE_LENGTH_ms 400 low level length of CYL SEL x define SWIL_LENGTH_us 300 low level lenghth of SWTL define EN_80_LENGTH_us 300 low level lenghth of EN_80 The initialization of the closed loop Peak amp Hold current algorithm define EN _LOW_ON MAX PEAK FIRST us 60 time inbetween low side switch EN_LOW is switched on in maximum at beginning of the injection define EN _LOW_ON MAX PEAK us 20 time inbetween Peak phase where low side switch EN_LOW is switched on in maximum should be bigger than period of SCOUT define EN _LOW_ON MAX HOLD us 30 time inbetween HOLD phase where low side switch EN_LOW is switched on in maximum should be bigger than period of SCOUT define EN_LOW_OFF_PEAK us 9 time inbetween low side switch is switched off during PEAK phase define EN_LOW_OFF_HOLD us 4 time inbetween low side switch is switched off during HOLD phase Application Note 30 2 1 2002 09 Infineon technologies AP32029 Peak amp Hold Current Shape generated by TriCore Software Application Example the initialization for the simulated SCOUT output generated by LT cells 27 30 valid beginning with injection pulse define SCOUT_PERIOD_1_us 12 period 1 of input stimuli SCOUT valid beginning with falling edge of EN_80 define SCOU
25. ow side switches This results in a fast decay of the free wheeling current This method cannot be applied directly to the configurations of block diagrams 1 and 2 because the high side switches needs a more complex controlling of their gates When the high side switches in block diagrams 1 and 2 are switched off without using a free wheeling circuit the source of the high side switches gets negative because of the inductivity from the coil and the switches itself into avalanche condition This affords some additional HW effort Therefore the given application SW and the build up demonstrator bases on the third system solution The PWM based low side switch current generation as shown in Figure 8 Application Note 12 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA 3 Closed Loop Current Control together with GPTA In the following chapter the General Purpose Timer Array GPTA within the TC1775 device is introduced Further a detailed explanation how to generate the corresponding control signals by using the Global Timer Cell Array GTCA and the Local Timer Cell Array LTCA is given General Overview DIGITAL PLL GY yyy yyy Lb blphiplilh blll ak RRA Clock Generation Unit g GTO Signal Generation Unit Ni ANNS NSSSSS S S LTC00 LTE Ot LT
26. owess of DSPs and highest performance price implementations of RISC load store architectures Automotive UnifieD prOcessor Peripheral Control Processor General Purpose Timer Array peripheral module within TC1775 TriCore derivative Global Timer Cell Array within GPTA Local Timer Cell Array within GPTA Application Specific Integrated Circuit Software Hardware Pulse Width Modulation High Side Switch Application Note 36 2 1 2002 09 Infineon goes for Business Excellence Business excellence means intelligent approaches and clearly defined processes which are both constantly under review and ultimately lead to good operating results Better operating results and business excellence mean less idleness and wastefulness for all of us more professional success more accurate information a better overview and thereby less frustration and more satisfaction Dr Ulrich Schumacher http www infineon com Published by Infineon Technologies AG
27. rol algorithm itself is performed by the Local Timer Cell Array The generated frame signals for the Peak amp Hold current waveform are for instance the selection of the injector or the length of the injector pulse itself Two informations are mandatory for a typical engine management system controlling a combustion motor 1 An angle based timer information angle domain which represents the exact position of the crankshaft and the camshaft of the engine 2 A time based timer information time domain where all relevant signal lengthes can be derived from These two basic timer informations are mapped within the GPTA module in HW to the 24 bit wide global timers GTO and GT1 The customers application SW calculates an engine position based start angle for the determination of the start of the injection pulse of a single injector for one cylinder The begin of injection pulse has to be mapped into the time domain and the corresponding injection pulse length has to be calculated Fehler Verweisquelle konnte nicht gefunden werden Figure 11 shows the dependency between the angle domain and the time domain Global Timers Angle Time l Timer Cell Globa er cells Injector pulse for Cylinder 1 Injector pulse for Cylinder 2 Injector pulse for Cylinder 3 Injector pulse for Cylinder 4 Figure 11 Realization of Injector Pulse together with GT0 1 and GTCs Application Note 15 2 1 2002 09
28. s will be discussed 2 1 System Overview The electronic circuit of a state of the art implementation consists of the following parts High voltage 80V for a fast injector response time Battery voltage used for the hold current of the valve Current measurement achieved by using a shunt resistor Current control with two high side switches peak current controlled by HSS2 hold current controlled by HSS1 e Cylinder selection achieved with low side switches Ves Shunt for Diagnosis Booster Ubat HSS1 55 V HSS2 100 V Injector Injector Booster Capacitor Vz 10 60 V Free wheeling Path Figure 2 Peak amp Hold Electronic Circuit Block Diagram Shunt for Current Control In this parallel highside switch configuration the Peak amp Hold current regulation has to be performed by controlling HSS2 switch with a PWM for the Peak_Time and HSS1 by a PWM for the Hold_Time As a representative for a state of the art common rail diesel direct injection system a coil driven current controlled injector can be found in Figure 3 below Application Note 5 2 1 2002 09 Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Requirements for Direct Injection Applications Technical Parameters e Pressure up to 1350 bar e Five nozzles of 0 12mm each e quantities down to 1mm as minimum dosage e coil impedance lt 0 4 Q
29. t The GPTA needs to be reconfigured for some application tasks To avoid bottlenecks in real time behaviour there has been implemented an interrupt driven Peripheral Control Processor PCP to the TC1775 The PCP is intended to be used for driving the peripheral set of the TC1775 The PCP could be used for instance for signal preconditioning and provide the filtered sensor input data to the application SW via a standardized API Application Programmers Interface Therefore a clear separation between the application layer and the physical layer within the embedded application can be achieved TriCore mcu psP INT Peripheral Control Processor 0 0 Figure 10 TC1775 System Partitioning The PCP executes its assembly instructions out of its own memory resources 16 KB Code SRAM and 4 KB Data SRAM and shares the 32 bit wide Flexible Peripheral Interconnection FPI bus together with the TriCore CPU This high speed 32 bit FPI bus connects all internal peripheral and system modules and all internal external memory portions within this multiprocessor architecture Application Note 14 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA 3 1 Usage of Global Timer Cell Array The Global Timer Cell Array basically is used to generate all signal outputs needed for the Peak amp Hold frame signals The current cont
30. t shapes for direct injection applications Figure 4 shows a possible partitioning for a Peak amp Hold direct injection system solution together with an ASIC HS1 60 100 mQ 50 V HS2 40 100 mQ 100 V 60 80 yv BUZ 110 SL Lee oeo maY SPB47N10L go 3 D y Ves e Converter HS 1 EN_12 HS 2 EN_80 HS 1 HS2 Figure 4 Direct Injector Drive for Peak amp Hold together with ASIC The usage of an ASIC summarizes the following benefits and features Reduction of external components Diodes Shunt Fully protection against overvoltage overload short circuit overtemperature ESD Automatical Current Shaping Full Diagnosis and Configuration via SPI interface Current matching between the channels Peak amp Hold current adjustable for different engines Increase of system reliability Decrease of system costs Application Note 8 2 1 2002 09 C Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Requirements for Direct Injection Applications Figure 5 shows a possible waveform for the Peak amp Hold current shape generation by using an ASIC The length of the peak time t1 and the off time t2 can be configured externally by using the SPI interface Tek DE moois 379 AOJE i Injector Current 00 J ee ee ee EN 80 Note t1 t2 are programmable EN 12 via SPI SSC Injector Pulse UD A a im 50 04 oe
31. the context with the start address of the corresponding channel but this has the disadvantages that it has to be calculated by the user and it has to be updated every time when a modification in the code is done which leads to another start address of the channel For this reason a channel entry table is used for the first call of the channels This channel entry table is located at the beginning of the PCP Code RAM and contains a jump to the corresponding channel whereby a label can be used The PC in the Application Note 24 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Partitioning context of each channel points to the corresponding jump instruction and the target address will be calculated by the assembler f initial start of Channel 1 SRPN 1 CH1 JC A CHIA cc_UC jump to start of channel 1 jinitial start of Channel 2 SRPN 2 CH2 JC A CH2A cc_UC jump to start of channel 2 CHIA CH2A 4 1 2 3 PCP Context Each channel has its own context which consists of eight 32 bit registers Depending on the context model two minimum context four small context or eight full context of these registers are automatically saved restored at channel start exit In this application the full context model is used The contexts of the different channels is stored in the PRAM Application Note 25 2 1 2002 09 Infineon technologies AP32029 Peak a
32. urrent Control by using a 4 Cell LTC Model This 4 cell LTC model consists of one injector current feedback input signal SCOUT external current sense compare input which generates a falling edge each time the current rises above a predefined threshold value It also supports one output signal EN_LOW which generates the control PWM for the current through the injector The model is driven by a Reset_Timer_1 LT cell and controls the injectors current autonomously without consuming any CPU PCP load Application Note 17 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA The completely HW based control mechanism works as follows A falling edge on input signal SCOUT generates simultaneously the below described HW driven actions The actual 16 bit timer value of Reset_Timer_1 is stored to SFR LTCxR and can be used for diagnosis purposes The Reset_Timer_1 will be cleared to zero and restarted The EN_LOW output gets a falling edge and therefore switches off the current Due to the reseted and restarted timer the current through the injector will remain switched off until the Reset_Timer_1 matches with LT cell Compare1 with the preprogrammed value EN_LOW_OFF_TIME This event generates a rising edge on output signal EN_LOW and therefore again enables the current through the coil The signal EN_LOW remains s
33. verview of configurable ParameterS ccccceccessceeeeeeeeeeeeeeeeseesseetsaees 30 5 2 Used GPTA Resources for the Peak amp Hold Generation ccceeeeeeeee 32 5 3 Connection to PC Terminal Program c ceccccsseeeseeeeeeeeeeeeeseeeeeneeeteaeeenetens 33 6 COMCIUSION niee adh ane araea ALLS ibecad tan deine 34 7 APD OMIOIX astinan a e E EEE EEEE 35 7 1 Related Documentation and SW Package ccceseceeeeeeeteeeeeeeseeeteeeetaes 35 7 2 List f FIQUIOS s ioiimiisonanspeta asi phe sect se bvgieevesieectweeseennsteaceryecceeeuedtienees 35 7 3 OAE lo e E ee 35 7 4 ADDIOVIAUONS soe ccin cise cecsadasedsavse airain a aeae a p aa a o aea EEA ETETETT 36 Application Note 3 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Introduction 1 Introduction The following application note deals with the generation of a Peak amp Hold Current Shape which becomes more and more popular in automotive application areas Especially in Powertrain applications like Direct Gasoline or Diesel Common Rail Direct Injection Combustion Engines the Peak amp Hold Current Shape is widely spread to drive the coils of conventional high pressure injectors In future Application Segments like Electronic Valve Control EVT systems the generation of a flexible Peak amp Hold current waveforms together with high voltage usage will be also a key success factor for precise electronic controlling of the valv
34. witched on at the beginning of the Peak_Time and switched off at the end of the Peak_Time Optional free wheeling diodes can be used dependant on the decay time of the inductance The current feedback is done like in the previous configuration in block diagram 1 Application Note 11 2 1 2002 09 eo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore System Requirements for Direct Injection Applications 2 2 2 3 Low Side Switch Current PWM Vhoost 80v HS_Switch EN_80 AUDO1 TC1775 TriCore HS_Switch EN_80 e LS_Switch_1 e LS_Switch_2 e LS_Switch_3 a LS_Switch_4 Injector CYL_1 Injector CYL_2 Injector CYL_3 Injector CYL_4 LS_Switch_1 CYL_SEL_1 f amp EN LOW f LS_Switch_2 CYL_SEL_2 amp EN_LOW LS_Switch_3 CYL_SEL_3 amp EN LOW LS_Switch_4 CYL_SEL_4 amp EN_LOW Threshold Value Figure 8 Block Diagram 3 for Low Side Switch Current PWM Only one high side switch see Figure 8 is used to select the high voltage for the Peak_Time of the Peak amp Hold current shape The low side switch is used both for the selection of the cylinder and for switching the current PWM This configuration affords some small additional glue logic logical AND for the signals CYL_SEL_x and the current control signal EN_LOW Free wheeling is achieved by zener clamping applied to the l
35. witched on until the coils current again rises above the predefined threshold and therefore generates a new capture event in LTC cell Capture_1 This mechanism is operable only if the measured current sense feedback input signal SCOUT reacts fast enough without having a to big hysteresis An additional LT cell Compare_2 is used to limit the maximum switch on time for the current through the coil to EN _LOW_MAX_ON_TIME The LTC Compare_2 cell is needed for safety reasons to avoid any damage to the injectors coil if for instance the current sense feedback signal SCOUT is broken Application Note 18 2 1 2002 09 oo Infineon AP32029 technologies Peak amp Hold Current Shape generated by TriCore Closed Loop Current Control together with GPTA 3 3 Overview about the complete generated Waveforms This chapter deals with a short summary of all the control signals generated by the GPTA module and it also shows a measured Peak amp Hold current waveform coming out of the build up demonstrator 1 4 Stop_Timer_1 m INT Delay Output of Low Side Switch for PWM external Sense Comperator Input Output of High Side Switch for 80V Event generates Interrupt Injector Pulse Cylinder Select x Switch Threshold Level Hold_Threshold IP CYL_SELx at ay gt INT Del Peak_Threshold Injector Curreht SWTL EN
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