I am currently using a K28 board to prototype out device. I receive data over USB which is written to a buffer and eventually I use DMA to write this buffer over QSPI to an FPGA. When the buffers are located in SRAM this works fine but I need to add some additional larger buffer. So I enable SDRAM and use buffers allocated there. I can receive the data over USB and by examining the SDRAM I can see the data is written successfully. However, for the DMA from SDRAM to QSPI I never get the DMA complete notification.
Since USB can write to SDRAM I assume SDRAM is configured properly so I'm not sure what to look at. Anyone done this or have any ideas?