For the PrimeCell SSP in the RP2040:
So, if you want the master to hold the CS (or "SS") pin low for multiple frames instead of raising it between every frame, you have to use a GPIO as CS and manage it yourself.in the case of continuous back-to-back transmissions, the SSPFSSOUT signal must be pulsed HIGH between
each data word transfer. This is because the slave select pin freezes the data in its serial peripheral register and does
not permit it to be altered if the SPH bit is logic zero. Therefore, the master device must raise the SSPFSSIN pin of the
slave device between each data transfer to enable the serial peripheral data write.
Statistics: Posted by carlk3 — Sun Apr 20, 2025 3:48 pm