I have a question about DMA reading and writing to a USART Master SPI port, more specifically about writing.
I can read the MSPI perfectly well using DMA, but I can't think of a way to write to it easily since the device needs its CS de-asserted/re-asserted.
The best I could think of without interrupts (which takes too much of the CPU time) is to have a DMA (1) to de-assert the CS, a DMA (2) to write to the MSPI, a DMA (3) to read the SPI, and a DMA (4) to re-assert the CS, but that doesn't seem very 'elegant'.
Is there a better way to do this? * Yeah. Ask it in the XMega forum for a start. Moderator. *