RM0440 Rev 4 1787/2126
RM0440 Serial peripheral interface / integrated interchip sound (SPI/I2S)
1791
39.9.7 SPI Tx CRC register (SPIx_TXCRCR)
Address offset: 0x18
Reset value: 0x0000
39.9.8 SPIx_I2S configuration register (SPIx_I2SCFGR)
Address offset: 0x1C
Reset value: 0x0000
Bits 15:0 RXCRC[15:0]: Rx CRC register
When CRC calculation is enabled, the RXCRC[15:0] bits contain the computed CRC value of
the subsequently received bytes. This register is reset when the CRCEN bit in SPIx_CR1
register is written to 1. The CRC is calculated serially using the polynomial programmed in
the SPIx_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 SPIx_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 SPIx_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.
These bits are not used in I
2
S mode.
1514131211109876543210
TXCRC[15:0]
rrrrrrrrrrrrrrrr
Bits 15:0 TXCRC[15:0]: 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 SPIx_CR1
is written to 1. The CRC is calculated serially using the polynomial programmed in the
SPIx_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 SPIx_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 SPIx_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.
These bits are not used in I
2
S mode.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Res. Res. Res.
ASTR
TEN
I2SMOD I2SE I2SCFG[1:0] PCMSYNC Res. I2SSTD[1:0] CKPOL DATLEN[1:0] CHLEN
rw rw rw rw rw rw rw rw rw rw rw rw