TMS320F28379D: EnDat Clock Issue: No PWM on GPIO6, Code Hangs in dataReady Check Loop

Hello,

There are software examples in C2000Ware that should help you with your code and PWM configuration : C:\ti\c2000\C2000Ware_5_04_00_00\driverlib\f2837xd\examples\cpu1\epwm

Please let me know if you have any questions.

Best regards,

Hello,

First of all, I would like to clarify that I am not unfamiliar with how to configure and run PWM on the TMS320F28379D. My current objective is to drive an encoder using the EnDat library, and I am initializing it with the EnDat_Init(); function.

During this initialization, the following functions are called:

PM_endat22_generateCRCTable(NBITS_POLY1, POLY1, endat22CRCtable);
PM_endat22_setupPeriph();
PM_endat22_setFreq(ENDAT_INIT_FREQ_DIVIDER);
retval1 = PM_endat22_setupCommand(ENCODER_RECEIVE_RESET, 0xAA, 0x2222, 0);
PM_endat22_startOperation();

However, these functions are defined in the precompiled PM_endat22_lib.lib file, so I am unable to inspect or debug the internal implementation directly.

I suspect that one of these functions—most likely PM_endat22_startOperation()—should be configuring and outputting a PWM clock signal on GPIO6. Unfortunately, no PWM signal is currently being generated on GPIO6. As a result, the SPI receive interrupt is never triggered, and the condition endat22Data.dataReady == 1 is never satisfied. This causes the program to remain stuck in the corresponding loop.

endat_init.zip

Please look at the code

Hello,

Thank you for further clarification. Let me loop in relevant experts on EnDat library to better assist you with your inquiry.

Hello again,

I’ve now resolved the previous issue — it appears the root cause was related to the .cmd file configuration.

I would like to ask a follow-up question.

I’m planning to use GPIO0, GPIO2, and GPIO4 as PWM outputs controlled by CPU2.

However, in the EnDat_Init() function, I see that the clocks for ePWM1, ePWM2, ePWM3, and ePWM4 are all being enabled:

CpuSysRegs.PCLKCR2.bit.EPWM1 = 1;

CpuSysRegs.PCLKCR2.bit.EPWM2 = 1;

CpuSysRegs.PCLKCR2.bit.EPWM3 = 1;

CpuSysRegs.PCLKCR2.bit.EPWM4 = 1;

This suggests that the EnDat library utilizes ePWM1 through ePWM4.

Given that, I’m concerned there might be a conflict if I also try to use any of those PWM modules (specifically ePWM1–ePWM3) from CPU2.

My question is:

When using EnDat, are all four ePWM modules (1–4) reserved exclusively for its use?

On this device the CLBx clock is driven by the ePWMx clock. As I recall 3 out of 4 of the CLB tiles are used. The author must have just initialized all 4 clocks. 

Regards

Lori