great code! i will be using this to read from an adc at 50kHz.. yielding about 1.2 Mbps traffic up and 600 kbps down. which should be peanuts compared to what you guys are doing with ethernet.
one question: can we use multiple dma streams at the same time? i see the code may need to be a bit extended? can the sam3x do this at all? typically, in a complex embedded system, there are multiple devices on the same SPI bus..