spi_issue.md

SPI issue notes

I'm attempting to do a loopback with SPI where I'm connecting the COPI with the CIPO and see that data is transferred.

While I can see that the RXNE flag is getting set:

(gdb) x/tw $r1
0x40013008:	00000000000000000000010000000011

I'm not able to write anything useful into the data register. What happens when I try is that all 1s get written:

(gdb) x/tw $r1
0x4001300c:	00000000000000001111111111111111

Why is this happening?