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TIM Capture compare timing resolution/jitter

HWhit.1
Associate III

I am developing an application using TIM3 with Direct-mode capture compare to measure short pulse widths of 1 to 32 microsec. I am using a Nucleo H7A3ZI-Q board for development. The clock speed is 260 MHz. The Direct capture compare on Ch1 is set the pulse duration by triggering on both input pulse edges.

My question is how much time jitter is there from when pulse arrives to the CC1 input till it is registered in CC1R register? I would guess one clock pulseis needed so the time-jitter would be one clock period. A timer resolution of one clock pulse is given in the specifications (Table 113). It is not clear to me if this also applies ot the capture compare input operation.

This probably needs advice from somebody in STM who has inside knowledge on the timer circuit.

Thanks in advance.

1 ACCEPTED SOLUTION

Accepted Solutions
TDK
Guru

The jitter/uncertainty is 1 timer tick. There is an additional fixed delay of a few timer ticks.

If you feel a post has answered your question, please click "Accept as Solution".

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2 REPLIES 2
TDK
Guru

The jitter/uncertainty is 1 timer tick. There is an additional fixed delay of a few timer ticks.

If you feel a post has answered your question, please click "Accept as Solution".
HWhit.1
Associate III

Thanks! This answered my question. The fixed delay is no problem for my application.