Hello.

Just for curiosity, I wrote the simple program:

CYCLE:
HIGH GPIO.0
LOW GPIO.0
GOTO CYCLE

Tried to run it on PIC12F683, with internal oscillator configured @ 4 mhz.
Measured output pulse frequency on GPIO.0 with digital scope. It was 100khz.

Configured internal oscillator to 8mhz.

Output pulse frequency become 200khz.

So, can be such performance decrease considered as normal?

Is it same for all MCUs?

I have to write some real-time functioning program, so I need to know the hardware limits. Since the looping sequence is one of the simplest one, I was expecting at least 1mhz with 4mhz oscillator, not 100khz.