STM32H563 SPI

[Dimlite]

Hi,

I could use some help getting started with SPI5 (limited feature set). I want to operate as SPI master and send a single byte. I want to control SS manually as ordinary GPIO out.

I've enabled the peripheral clock, and I can see in the debugger that FIFO flag TXTF goes high when I write to TXDR, and that I set CSTART. But nothing comes on MOSI or SCK, and EOT is never set.

Do you spot anything obvious in the code below?

What puzzles me is that if I set SSIOP = 0 and use the same code, TXTF and CSTART is not set. SSIOP should not be of importance when the peripheral is not in control of SS, right?

// Enable AF on MOSI, MISO, SCK. Set CS 1 and 2 as outputs (manual control).

GPIOF->MODER = (GPIOF->MODER & 0b11111111111100000011110000111111) | 0b00000000000010101000000101000000;

SPI5->CFG1 = 0b01110000000000000000000000000000;

SPI5->CFG2 = 0b10010001010000000000000000000000;

SPI5->CR2 = 1;

SPI5->CR1 = BIT(0);

SPI5->IFCR |= BIT(3); // Clear EOT flag.

SPI5->TXDR = data; // Load FIFO.

SPI5->CR1 |= BIT(9); // Transfer start.

// Wait for EOT.

while ((SPI5->SR & BIT(3)) == 0)

;

[Dimlite · Accepted solution]

I solved it.

With the two lines below missing, the MCU got stuck waiting for an EOT that never came.

// Select AF5 (SPI MOSI, MISO and SCK) on PORTF[9:7]
GPIOF->AFR[0] |= 0x50000000;
GPIOF->AFR[1] |= 0x00000055;

I would have expected nothing to show up on the I/O-pins, but not the actual register writing and reading to be affected. Oh well, assumption is the mother of all **bleep** ups 🙂

Attached is the working code.

[Issamos]

Good job 💪

Mark your answer as best answer to be diffused to everyone.

Best regards.

II

[sebxx4]

Does your code works fine?
And did you make // TODO: ensure TXP == 1 in SR?