I agree that something along those lines may be the reason for why the CS line stays low between subsequent transfers, at low baud rates. Though I haven't really dived into the documentation for the SPI peripheral itself, yet.
What bothers me is why the spi_write_read function does not wait for the PrimeCell SPI peripheral BSY bit to clear before returning. That's what the blocking write function from the SDK does, and it fixes this issue.
Obviously implementing CS in software circumvents this problem, but why not use the hardware if it exists? One less thing to do (and go wrong) in software is always a good thing in my book.
What bothers me is why the spi_write_read function does not wait for the PrimeCell SPI peripheral BSY bit to clear before returning. That's what the blocking write function from the SDK does, and it fixes this issue.
Obviously implementing CS in software circumvents this problem, but why not use the hardware if it exists? One less thing to do (and go wrong) in software is always a good thing in my book.
Statistics: Posted by KTS — Thu Feb 01, 2024 9:01 am