swift-nav/piksi_firmware — pull request #38 by gsmcmullin (2014-04-29 21:38:56+00:00)
Title: Use DMA for long SPI transfers with FPGA.

Using DMA for SPI transfers allows other threads to run during transfers. This increases idle time by 10% when tracking 8 satellites if we yield on transfers of 8 bytes and over. For shorter transfers it is still better to spin because of the overhead of context switching.