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SPI configuration

Gregory_1
Associate

Good morning,

I'm new to using the STM32. I have a Nucleo H755ZI-Q development kit.

I need to write a command to SPI port type 0xfcd8000 or 0xfcb85b0 or 0x12000000. The max frame can be 32 bits.

On the oscilloscope, I do have an SPI frame, but I always have an additional 0 bit at the end.

I need to keep the value on the falling edge of the clock.

When I write 0xfcd8000 (1111 1100 1101 1000 0000 0000 0000) , the SPI port writes 0x1F9B 0000 (0001 1111 1001 1011 0000 0000 0000 0000).

It took me a while to configure it and I probably made a mistake. Could someone check my settings?

Thank you in advance for your help.

Gregory_1_0-1730891175976.png

 

void SEND_COMMAND(uint32_t DATA)
{
	/*SPI_DATA_SEND[0] = (DATA >> 24) & 0xFF;
	SPI_DATA_SEND[1] = (DATA >> 16) & 0xFF;
	SPI_DATA_SEND[2] = (DATA >> 8) & 0xFF;
	SPI_DATA_SEND[3] = DATA & 0xFF;*/

	WAIT_BUSY();
	HAL_GPIO_WritePin(GPIOB, CS1_AD5522_Pin, GPIO_PIN_RESET);
	/*HAL_SPI_Transmit(&hspi1, SPI_DATA_SEND, 4, 1000);*/
	 HAL_SPI_Transmit(&hspi1, (uint8_t*)&DATA, 1, 1000);
	HAL_GPIO_WritePin(GPIOB, CS1_AD5522_Pin, GPIO_PIN_SET);
}

SEND_COMMAND(0xfcbb8e4);

 

1 REPLY 1
gbm
Lead III

Check the CPOL and CPHA settings required by your slave circuit and set them accordingly in SPI config.

My STM32 stuff on github - compact USB device stack and more: https://github.com/gbm-ii/gbmUSBdevice