Compiler: RPT instruction

Setting the RPT threshold to 0 is a special value meaning "unlimited." If you want to prevent the compiler from generating any RPT instructions at all, you must use the --no_rpt (or -mi) option.

I'm sorry, I'm not familiar enough with C28x to know which instructions disable interrupts. You would be better off asking this in the microcontroller forum.

Thanks a lot.

Can some one give me a reply about "During RPT, interrupt will be disabled; besides RPT, is there any other instruction, which can disable interrupt during its executing?"?
Thanks in advance.
Br, Jordan

Hi Jordan,

My understanding is that the RPT instruction is uninterruptable because it's treated like a single instruction and the CPU will complete code execution of the current instruction before it saves the context and fetches the interrupt vector. You could see similar behavior with other instructions that take multiple cycles like branches.

Whitney

Whitney,
Is there any other instruction, which is uninterruptable?
Thanks a lot.
Br, Jordan

Hi Jordan,

This also applies to other instructions that take multiple cycles. Branch instructions are one example. You can refer to the CPU and instruction set reference guide for cycle counts for all instructions.

Whitney

Whitney,

Sorry, I made you confused. Actually I'd like to know, if there are some other instructions, which cost a lot of CPU cycles.

Customer's issue is, after setting optimization level 2, RPT was generated. The repeat time is large like 100 times. During the 100 times RPT execution, ADC interrupt can't be serviced in time. This destroyed the PWM frequency.

Normal instruction cycles are not a problem for them.

Thanks a lot.

Br, Jordan