Hello
I am using STM32H7R3L8 MCU and STM32CubeIde v1.19.0. I have an issue where if I was to use SPI4 in Motorola mode together with CPOL=0 and CPHA=1, it works fine. It also works fine when I was to do SPI TX via DMA. Although, as I have the need to have CS inactive between each half-word being sent, I tried using the NSSP option of the SPI, which, when zoomed out on the logic analyzer view, seems to have an issue. Problem is, that at random points during a sequence of 1 half-word size transmits, SCLK and CS sometimes change their states at the same time, causing errors visible on logic analyzer and it seems like the slave device also can not handle that.
Configuration:
SPI4 in Motorola master mode
HAL driver
DMA transmit
- Hardware NSS control
CPOL = 0, CPHA = 1 (SPI_PHASE_2EDGE)
NSS active low
NSS pulse mode (NSSP) enabled
Is the combination of CPOL=0, CPHA=1 and NSSP not functional? Should I be controlling the CS in software mode instead? Or am I missing something else?
I have also added images of 2 half-word transmits one after another. First working, then error. Slight differences between SCLK and CS timings can be seen.
Thank you in advance
