TMS320F280039: CLA not entering task

Hang,

I don't see how changing the upper limit on the variable in the for loop would keep the task from running. If the task is configured the same in case 1 and case 2 then it should start with the ADC trigger. 

Hang Yang said:

This is just an empty loop. Actually, the program will never reach this loop because there is "if" condition wrapping this loop and the condition will always be false.

Are you saying the compiler optimizes the loop away? If the compiler determines that the outer "if" is always false then it may eliminate the inner "for" since it will never be executed.

How are you determining the task is not running? Please try putting a debug breakpoint in the task and see if the task halts.

Hi Lori，

I determine that the task is not running based on:

 1. Adding break point using MDEBUGSTOP to the task. In case 1, CLA halts at the break point. In case 2, CLA does not halt.

 2. There is an incrementing variable at a first line of the task, like "cnt++", this variable should increase by 1 every time the task executes. In case 1, this value increases, in case 2, it doesn't.

Lori Heustess said:

Are you saying the compiler optimizes the loop away? I

This is unlikely. After turning optimization from 0 to off, the task does not run even in case 1. Additionally, I checked size of CLA program in case 1 and case 2 (with optimization) , the code size of case 2 is slightly larger than case 1, by tens of bytes. This empty loop should remain in the compiled codes to make these two differences.

Thought I determined that the task is not running in case 2 based on the above two facts, there is another fact that the MIFR bit and MIOVF bit is toggling. My interpretation is CLA has entered the "task", but it actually jumps to some other address. But when I check the MVECT register, they are the same as case 1.

Regards,

Hang.