I am using a K22FN on a custom board where I am interfacing SPI1 in slave mode to some SPI 'like' master device.
This device does not generate a chip select signal. Instead it uses two I/O signals. One to signal the start of a new cycle and one to signal the start of new 16 bit word transfer after which the clock starts for the data transfer.
As such I had not connected the PCS0 input and instead configured that pin as a general I/O.
However, I can't seem to get my device to transmit anything in slave mode.
Does the PCS0 need to be used? Or can I set it to enabled in software? If not, can I tie the pin to a fixed level?