use ppi and set usb sof as rtc1 source

RE: use ppi and set usb sof as rtc1 source

Kenneth — Thu, 14 Oct 2021 07:42:53 GMT

Sounds good. You are right, you will need to use a timer yes.

Kenneth

RE: use ppi and set usb sof as rtc1 source

astella — Wed, 13 Oct 2021 13:05:02 GMT

Hi Kenneth, yes you got my meaning, thank you. Latest question, what you are suggesting wouldn't be possible for rtc1, thought, would it? I mean it seems not to have a counter mode, or am I wrong. Should be the case we should use another hardware timer, that is ok for us, as we don't have power issue, in this particular project. Thank you

RE: use ppi and set usb sof as rtc1 source

Kenneth — Wed, 13 Oct 2021 11:44:58 GMT

Not sure if I understand what you want to achieve here, but why not just use the timer in counter mode, and connect SOF event to the COUNTER task of the timer?

Kenneth

RE: use ppi and set usb sof as rtc1 source

astella — Tue, 12 Oct 2021 14:37:20 GMT

Maybe the theoretical problem here is that overflow is writing 0x00FFFFF0, not actually forcing an immediate overflow interrupt in rtc1. so if rtc1 frequency is not higher than usb one, this doesn't work. I'd rather use a mechanism that is forcing an immediate rtc1 interrupt if possible. How would be a cool way using PPI to have a timer and usb in sync in your opinion? Thank you