I have a A/D where signals CPU(Analog Devices Blackfin 706) whenever it has new sample, and CPU reads that through a SPI, which is few bytes. Then waits for new smaple signal again.
My question is, can we use DMA here? Who and how should tell DMA to transfer new data? I can't tell DMA to watch for the signal itself, so somebody has to do it.
Does it make sense to use DMA? This is basically like an interrupt I/O. Everytime A/D signals new sample, main software tells DMA to transfer it. So there is no improvement in efficiency. main is still involved continuously in I/O.