Synchronize SPI clock with generated timer clock

RE: Synchronize SPI clock with generated timer clock

ovrebekk — Fri, 13 Nov 2020 08:48:30 GMT

The best of luck 🙂

Unless you have more questions I will consider the case closed.

RE: Synchronize SPI clock with generated timer clock

49bwjf8 — Wed, 11 Nov 2020 20:54:31 GMT

Will do, thank you.

RE: Synchronize SPI clock with generated timer clock

ovrebekk — Mon, 09 Nov 2020 10:18:28 GMT

According to the SPIM electrical specification this delay is 1us typical.

There are no min and max values unfortunately. I don't see any reason why it would be non deterministic, but I would recommend doing some testing to verify this.

Best regards
Torbjørn

RE: Synchronize SPI clock with generated timer clock

49bwjf8 — Fri, 06 Nov 2020 15:32:21 GMT

Thanks for your reply! I am using nRF5 SDK v15.3.0 and am using nrf_drv_spi.

Is the time between starting the SPI peripheral and the rising edge of the clock deterministic?

RE: Synchronize SPI clock with generated timer clock

ovrebekk — Fri, 06 Nov 2020 13:12:27 GMT

You probably need to start the SPI interface in sync with the 1MHz clock put out by Timer 1. This should be possible by connecting the START task of the SPI peripheral to the compare event generated by timer 1 over PPI.

Can you let me know which SDK version you are using, and which driver you are using for the SPI?

Best regards
Torbjørn