andreobi
Junior Member

I think I got a solution for me - I changed to timer GTP1, it is muche more pecise for higher frequency - and I also lift up the interrupt priority, so the timer comes ahead the serial communication

My assumption is: the serial interrupt is preparing the next byte to send ( this seems to take upto 530ns) and the timer interrupt happend in that time. So the timer interrupt handling is delayed. If the delay is to...

Basicly I changed the serial output to Serial1 for easier pin access. I set the interrupt timing to 1000kHz. CPU 600MHz, and PeriodicTimer t1(TMR3); on the snapshot you can see that the interrrupt (yellow) schifts...

Thanks, it is a good advise to use the TMR source. It runs now without glitches. I assume it has something to do with the IO structure using the timer and serial port. As a "nice" sideeffect now I have to define...

I just tried your hints - taking out the cli and sei has no influence on the situation but is basicly a good hint - the scope capture is with peek detect and 100 MHz bandwidth and digital 300MHz so I don't believe it...