4.4.3.10. Motorola SPI Format with SPO=0, SPH=0 in RP2040 Datasheet says
In the case of a single word transmission, after all bits of the data word have been transferred, the SSPFSSOUT line is
returned to its idle HIGH state one SSPCLKOUT period after the last bit has been captured.
However, 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. On completion of the continuous
transfer, the SSPFSSOUT pin is returned to its idle state one SSPCLKOUT period after the last bit has been captured.
Statistics: Posted by carlk3 — Tue Sep 03, 2024 10:40 pm