STMicroelectronics /STM32U031 /SPI1 /SPI_TXCRCR

Tx CRC register When CRC calculation is enabled, the TXCRC[7:0] bits contain the computed CRC value of the subsequently transmitted bytes. This register is reset when the CRCEN bit of SPI_CR1 is written to 1. The CRC is calculated serially using the polynomial programmed in the SPI_CRCPR register. Only the 8 LSB bits are considered when the CRC frame format is set to be 8-bit length (CRCL bit in the SPI_CR1 is cleared). CRC calculation is done based on any CRC8 standard. The entire 16-bits of this register are considered when a 16-bit CRC frame format is selected (CRCL bit in the SPI_CR1 register is set). CRC calculation is done based on any CRC16 standard. Note: A read to this register when the BSY flag is set could return an incorrect value.