DocID018909 Rev 11
915/1731
RM0090
Serial peripheral interface (SPI)
918
28.5.8 SPI_I
2
S configuration register (SPI_I2SCFGR)
Address offset: 0x1C
Reset value: 0x0000
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 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 data frame format is set to be 8-bit data (DFF
bit of 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 data frame format is selected
(DFF bit of 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.
These bits are not used for I
2
S mode.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
I2SMOD
I2SE
I2SCFG
PCMSY
NC
Res.
I2SSTD
CKPOL
DATLEN
CHLEN
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 15:12 Reserved, must be kept at reset value.
Bit 11
I2SMOD
: I2S mode selection
0: SPI mode is selected
1: I2S mode is selected
Note: This bit should be configured when the SPI or I
2
S is disabled
Bit 10
I2SE
: I2S Enable
0: I
2
S peripheral is disabled
1: I
2
S peripheral is enabled
Note: This bit is not used in SPI mode.
Bits 9:8
I2SCFG
:
I2S configuration mode
00: Slave - transmit
01: Slave - receive
10: Master - transmit
11: Master - receive
Note: This bit should be configured when the I
2
S is disabled.
It is not used in SPI mode.
Bit 7
PCMSYNC
: PCM frame synchronization
0: Short frame synchronization
1: Long frame synchronization
Note: This bit has a meaning only if I2SSTD = 11 (PCM standard is used)
It is not used in SPI mode.
Bit 6 Reserved: forced at 0 by hardware