Cycle Time Background Task

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User20052
Level 1
Level 1
Hi All,

I'm running a background task, which is just a simple increment:

while(1){
counter++
}

I see that the runtime of the loop to increase counter to a fixed value heavily jitters.
Assembler code looks OK, there is no optimization. So I think the AURIX architecture does some prediction or optimization. Am I right?
Is there any option to switch the optimization off? I need a predictable runtime.

Many thanks!
Regards,
Aitschebeet
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2 Replies
NeMa_4793301
Level 6
Level 6
10 likes received 10 solutions authored 5 solutions authored
How much jitter is "heavily"? The AURIX TriCore CPU does do some speculative fetching, but in most cases, that only results in ~30 ns of variation. Otherwise, AURIX latency is generally very predictable.

Do you have interrupts enabled? Could a periodic interrupt be throwing things off?
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User20052
Level 1
Level 1
Hey UC_wrangler,

Thanks for your reply. Finally, I observed that the debug information was just wrong.
The AURIX studio integrated debugger is really messy. :mad: It very often shows wrong variable values.

Regards,
Aitschebeet
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