SPI blocking or nonblocking?

[Emil]

Just to make sure: Will The spi_master_send_recv return when it is done writing and reading, or do you have to have some event wait functionality listening to SPI_MASTER_EVT_TRANSFER_COMPLETED ? I guess it is blocking because you have an output buffer as well...

I am going to do large burst reads having <= 24576 bytes. Is it even possible to read that much in one go memory wise?

Thanks!

[Emil]

Yeah, I need it in top and bottom. But another important thing is to know for certain that sd_app_evt_wait falls through AFTER the handler is called, if it falls through before, it will wait forever for next transfer (?)

[Susheel Nuguru]

it calls _WFE, so it falls through only after. Read the discussion regarding this. devzone.nordicsemi.com/.../

[Emil]

Thank you! That cleared everything up!

[wim]

question: I also use a blocking mechanism with a flag. Is it guaranteed to get a SPI_MASTER_EVT_TRANSFER_COMPLETED? or do I need to cover other cases? Or do I need to put a safety timeout to exit my while loop if the SPI access takes to much time?

[Emil]

The SDK has changed, but it should always return. Also you might want to handle SPI_MASTER_EVT_TRANSFER_ABORTED.

I changed from this SPI library to an SPI library that is simpler and doesn't use events. This is much tighter and faster and you don't need to have this logic: devzone.nordicsemi.com/.../