I'd like to use the SCLK pin as a clock output. I don't care what MOSI and MISO are doing, and I don't want to reload the transmit register or do anything in an ISR. I just want a free running clock output from the SCLK pin. Is this possible?
From the description of the SZ bit in SPI_CTL I thought I could write SPI_TDBR once and it would be reloaded with 0s or the last transmitted word. That doesn't work with TIMOD 00 or 01.
I haven't tried DMA mode, could I set up a circular DMA transfer and ignore the interrupts to achieve what I want?