TMS320F28035: CLA debugging with MDEBUGSTOP 'delay'

Matias Anun

Part Number: TMS320F28035

Hello TI family,

I am trying to understand the reason behind the behavior I am observing while working with piccolo TMS320F28035 and the CLA.

I have coded CLA task 1 to run with ADCINT_1 at 40kHz and trigger CLA1_ISR upon completion. I have verified correct operation with a scope by outputting a signal with a GPIO.

Now, when I add a MDEBUGSTOP to the task, I can observed that the CLA task executes several times (a lot) before actually stopping at the MDEBUGSTOP instruction. It happens several cycles afterwards.

One attempt I did to see what is going on: I put a breakpoint on the CPU just before forcing task 1 to run (I removed ADCINT_1 as trigger source). If I step in, then the CLA actually stops in this first execution.

I am not able to find a precise explanation on datasheets and forum threads. Anyone with knowledge on this? I am just trying to understand this delay with the debugger.

Some info that perhaps is needed:

CCS 6.1.3

JTAG with XDS100v2

Thanks,

Matias

over 7 years ago

0 Sal Pezzino over 7 years ago

TI__Mastermind 32995 points

Hi Matias,

I have not heard of this happening nor experienced this.

Make sure that you have the CLA connected in the DEBUG window. The CLA will not halt unless the CLA is connected.

sal

0 Matias Anun over 7 years ago in reply to Sal Pezzino

Intellectual 360 points

Hi Sal,

CLA is connected and with symbols loaded.
I agree, is pretty strange. I will keep working and will post if I find anything.

Thanks,

Matias

0 Sal Pezzino over 7 years ago in reply to Matias Anun

TI__Mastermind 32995 points

I have noticed that it may take about 1 second for the debugger to recognize that the CLA is halted. And to update the CLA PC counter when I am viewing the C28x. But I have not noticed it missing an MDEBUGSTOP.

sal

0 Matias Anun over 7 years ago in reply to Sal Pezzino

Intellectual 360 points

Right, that would be ok, if it was CCS/debugger taking some time to respond. The intriguing part is that I see several CLA_task1_ISR() executions.
I am trying to find out that my observations are wrong, but I've got nothing yet.

0 Devin Cottier over 7 years ago in reply to Matias Anun

TI__Guru 60865 points

Hi Matias,

Were you able to resolve your issue?

0 Sal Pezzino over 7 years ago in reply to Matias Anun

TI__Mastermind 32995 points

Matias,

Can you please send the conclusion of your debug? What was the issue? How was it resolved?

sal

0 Matias Anun over 7 years ago in reply to Sal Pezzino

Intellectual 360 points

Hello,

I do not have a solution as per the definition of the word.

To be able to debug properly and have the debugger stop at MDEBUGSTOP I run the device up to the initialization of the CLA just before forcing CLA task 1 to run. Then the debugger feels comfortable enough to do its job.

Sadly, I do not have a lot of spare time to try and fully understand the problem and it is not the only funny thing I have seen around the debugger.

I only have that workaround.

Matias

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F28035: CLA debugging with MDEBUGSTOP 'delay'