Other Parts Discussed in Thread: CC3220SF, , CC3220S-LAUNCHXL
Posting this to hopefully help other users having issues getting the SPI peripheral working. After a few days of debugging, I have written my own SPI driver that is accessing the SPI registers directly to do a simple SPI loopback test. In hardware, I have the MOSI tied directly to the MISO pin on the CC3220SF. The symptoms I am seeing is that the value in the SPI_RX register does not seem to be related at all to what is physically present on the MISO pin. I tried writing every value between 0 and 255 and I get a repeating pattern of 16 values back on the SPI_RX.
After trying every possible setting in the various SPI config registers I eventually tried moving the SPI clk from PIN_05 to PIN_45. This fix resolved the issue and I was getting the expected values back in the SPI_RX register. I tried this on two boards, a CC3220SF-LAUNCHXL and a CC3220S-LAUNCHXL.
I am expecting previously ordered PCBs to arrive this week and will update on how they perform. I expect to have to do some rework to move the SPI clk to the new pin.
