_nop_()

At 24 MHz, the CPU cycle is 41+2/3 ns. Instruction execution time is at least 2 CPU cycles for the C166 CPU. The NOP instruction is executed in 2 CPU cycles, that is 83+1/3 ns. Of course, you have to take into account interrupts, CPU pipeline effects from the previous instructions and so on.
I have used the ST10F168 microcontroller quite a bit, and I have checked those times carefully with long loops and a stopwatch, so you can rely on them :-)

Regards,
- mike

At 24 MHz, the CPU cycle is 41+2/3 ns. Instruction execution time is at least 2 CPU cycles for the C166 CPU. The NOP instruction is executed in 2 CPU cycles, that is 83+1/3 ns. Of course, you have to take into account interrupts, CPU pipeline effects from the previous instructions and so on.
I have used the ST10F168 microcontroller quite a bit, and I have checked those times carefully with long loops and a stopwatch, so you can rely on them :-)

Regards,
- mike

I have checked those times carefully with... a stopwatch

I'd second the results, but the nanosecond hand on my stopwatch broke off, and I haven't bought a new one.

Thanks Mike, that comes to confirm what I thought !

Best regards