Are there code examples for using the SPI slave on avr32? I am familiar with SPI on avr(8bit).
Ideally, I'd like to poll for CSN going down to know that my application must provide a status byte for the return. And with CSN low incoming bits are latched on clock edges. My application then polls a status register to know if a byte is received.
I'd like to avoid interrupts, the application runs critical real-time stuff. Instead, the SPI master can be instructed to be well-behaved and insert time for the poll loops to respond.