TMS320F28379D: Dual Core operation using peripherals

Hi Leon,

Did you add the complete EPWM configurations? Where are the action qualifiers? I just added EPWM to CPU1 sysconfig file with a similar configuration to your EPWM (but set my action qualifiers to high on 0, low on CMPA-up) and ran it successfully:

I did not add the sysctrl to mine - is there a specific reason you did so?

Best Regards,

Allison

Hi Allison,

I apologize for the delayed reply.

You are correct about the action qualifiers. I forgot this part of the configuration. As soon as I added it, I was able to get a square wave from the designated output. Furthermore, I added Event Trigger for EPWM1 and ADCA in the sysconfig. In addition, I added a GPIO32 pin to the code to control it from ADC ISR. Thus, I was able to see the GPIO32 toggle as well.

I added SYSCTL to set up EPWM2 and ADCB with CPU2. I reproduce the same configurations for EPWM2 and ADCB as I used for EPWM1 and ADCA. When I flash the code in the device, I can see the EPWM2 output toggles as expected, but the designated GPIO pin (GPIO19 designated for CPU2) will not toggle. I was unable to find a solution for that.

I added the SYSCTL module only to CPU1 in the SYSCONFIG file.

Can you help me to trace this issue?

Regards
Leon

Hi Leon,

Allison is out of office today, so please expect some delay in her response.

Best Regards,

Delaney

Hi Leonid,

Glad you were able to get the EPWMs working!

For the GPIOs, you have to designate control of the GPIO to CPU2. I found a few similar threads regarding this. Please take a look and let me know if these are helpful to resolve the issue:

• https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/498293/tms320f2837xd-accessing-gpio-by-cpu2 
• https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1001168/tms320f28379d-gpio-control-from-core-2
• https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/980734/tms320f28379d-regarding-gpio-run-by-cpu2

Best Regards,

Allison

Hi Alison,

Thank you for your reply.

I think there was miscommunication between us. The GPIO19 is designated for CPU2. I tested a control over the pin in the main routine. After I established control over the GPIO pin and saw EPWM output on the other pin, I added ADCB to CPU2. I created ISR for ADCB where it only toggles the GPIO19 and clears ADCB flags:

This is my setup for ADCB:

EPWM2 Setup:

SYSCTL module in CPU1:

The only thing I added to the example from Resource Explorer is the EPWM and ADC modules for each core. Inside ADC interrupt I am toggling a GPIO pin.

Please let me know what could be a reason for ADC ISR on the CPU2 not to trigger.

Regards,

Leon

Hi Leon,

Apologies, yes I misinterpreted your post. 

So the issue is that your ADC ISR is not being called (which is manifesting in that the GPIO19 is not toggling in the ADCB ISR), right?

Are you connected via CCS when running? Can you please step through to code and use breakpoints (and then you can also check the registers/register flags) to confirm that the ADCB SOC etc. is being triggered by EPWM2 as expected? 

Best Regards,

Allison

Hello Allison,

I apologize for the delayed reply. I was away for a few days.

I figured out the issue with the problem I was experiencing. It is the same problem I had with CPU1 when setting it with the new peripherals, but I forgot about it. The project, as it is imported from Resource Explorer, has a function call Board_init() before Interrupt_initModule() and Interrupt_initVectorTable() calls. Thus, the interrupt initialization functions override interrupt registrations created in the Board_init() function. As soon as I placed the Board_init() function call after interrupt initialization, the issue was resolved.

However, I encountered a new problem after I added SCIA module to CPU1. Using the same approach as above for interrupts, I designated GPIO18 for CPU1 and placed control over it in SCIA ISR. When I run the program with the debugger, I see the GPIO18 toggle any time I send a character from a terminal program. However, when I flash the standalone program, the SCIA ISR never triggers. The EPWM and ADCA ISR work properly as before.

This is Sysconfig changes for SCIA:

SCIA ISR:

I never encountered such an issue previously. Do you know what could cause such an unusual problem?

Regards,
Leon

Hi Leon,

No worries - ah yes the Sysconfig Board_init() settings can be overwritten by code called after it (or vice versa). Glad you were able to resolve that piece.

Hmm I had an almost similar sounding issue with someone else the other day- could you please have a look at this thread and see if my suggestions or the resolution there are helpful at all? https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1372411/tms320f280025c-tms320f280025c-sci-communication-not-working-in-standalone-mode. 

If nothing there helps, I'll take a closer look.

Best Regards,

Allison

Hi Allison,

Thank you. Let me look into this and I will update you.

Regards,
Leon

Sounds good, Leon. I will await a response.

Best,

Allison

Hi Alliston,

Thank you for pointing me to the other post. I just went through the other post and it pointed me in the right direction. Following the other post approach I checked the SCI status register in the main loop and found that at the start of the program, the SCI RXERROR bit is getting toggled multiple times (repeatedly returns after the SCI reset command). Further investigation shows that the BRKDT flag is the main culprit for the failure. As it turns out I did not consider the bootup time of the FTDI chip. Placing the scope of the RX pin, I captured the signal on channel 1:

The FTDI chip holds RX pin low for approx 200+mSec. After I introduced a 300mSec delay before SCI initialization, the issue seemed to be resolved. I am still running some checks, but I believe the FTDI bootup time was the issue that I was fighting.

Regards,
Leon

Hi Leonid,

Glad to hear you were able to make some progress! yes, let me know how the checks go.

Best Regards,

Allison