In SX Microcontrollers, SX/B Compiler and SX-Key Tool, g_daubach wrote:

Hi all,

I noticed similar problems in the past when debugging SX code, i.e. that the debugger seems to not always "catch" an RTCC rollover interrupt while single-stepping through the code. Maybe, this really occurs when an interrupt is fired right in the middle of a jmp, call or skip instruction, i.e. in situations where the instruction pipeline needs to be cleared up. Inserting NOPs somewhere in the code cause a slight shift in timing so that interrupts are fired when the main code does not just perform a branch.

On the other hand, by setting a breakpoint inside the ISR, I could verify in RUN mode that the SX per-se does not miss any RTCC rollover interrupts (provided the total execution time of the ISR is below the interrupt period).

I don't think that this is a bug in the SX-Key IDE part of the debugger but that this is caused by some limitations of the SX in-system debugging feature, similar to the fact that you can't set a breakpoint on a NOP instruction, and that program execution stops only after the "breakpointed" instruction has been executed.

I think we will have to live with these "features" but I felt free to not implement similar "features" in SXSim :-) .

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