We are testing the SPI DMA demo code (spi_dma_lib_demo) which uses SPIReadWrite() to trigger a DMA SPI transfer.
We need an acquisition thread implementing continuous SPI DMA data reception, into two buffers (double buffering).
On the oscilloscope hooked to the SPI port, two consecutive calls to SPIReadWrite within the acquisition thread show a >25 useconds latency betwen consecutive bursts of SPI clocks. We loose ADC data due to this dead time.
How can we re-trigger the SPI within the acquisition thread w/o such a huge dead time between consecutive SPI DMA bursts? Max. for our application is 1usecond.