I am trying to get the hardware to control the NSS line on a SPI bus but it is not cooperating. I am talking to a DAC that requires 16 bits per transmission and 4 transmissions because its a quad DAC. The NSS line needs to go low at the beginning of the transmission (16 bits) and then go high again until the next transmission. I tried all the setting but could not get the hardware to do this. I am generating NSS manually through software right now, but I want to use DMA for this and need the hardware to handle the NSS line. Any ideas?