AT32F425
Series Reference Manual
2022.03.30
Page 184
Ver 2.01
Bit 0
RDBF
0x0
ro
Receive data buffer full
0: Transmit data buffer is not full.
1: Transmit data buffer is full.
13.4.4 SPI data register (SPI_DT)
Bit
Register
Reset value
Type
Description
Bit 15: 0
DT
0x0000
rw
Data value
This register controls read and write operations. When the
data bit is set as 8 bit, only the 8-bit LSB [7: 0] is valid.
13.4.5 SPICRC register (SPI_CPOLY) (Not used in I
2
S mode)
Bit
Register
Reset value
Type
Description
Bit 15: 0
CPOLY
0x0007
rw
CRC polynomial
This register contains the polynomial used for CRC
calculation.
Note: This register is valid only in SPI mode.
13.4.6 SPIRxCRC register (SPI_RCRC) (Not used in I
2
S mode)
Bit
Register
Reset value
Type
Description
Bit 15: 0
RCRC
0x0000
ro
Receive CRC
When CRC calculation is enabled, this register contains
the CRC value computed based on the received data. This
register is reset when the CCEN bit in the SPI_CTRL1
register is cleared.
When the data frame format is set to 8-bit data, only the 8-
bit LSB ([7: 0]) are calculated based on CRC8 standard;
when 16-bit data bit is selected, follow CRC16 standard.
Note: This register is only used in SPI mode.
13.4.7 SPITxCRC register (SPI_TCRC)
Bit
Register
Reset value
Type
Description
Bit 15: 0
TCRC
0x0000
ro
Transmit CRC
When CRC calculation is enabled, this register contains
the CRC value computed based on the transmitted data.
This register is reset when the CCEN bit in the SPI_CTRL1
register is cleared.
When the data frame format is set to 8-bit data, only the 8-
bit LSB ([7: 0]) are calculated based on CRC8 standard;
when 16-bit data bit is selected, follow CRC16 standard.
Note: This register is only used in SPI mode.
13.4.8 SPI_I2S register (SPI_I2SCTRL)
Bit
Register
Reset value
Type
Description
Bit 15: 12 Reserved
0x0
resd
Forced 0 by hardware.
Bit 11
I2SMSEL
0x0
rw
I
2
S mode select
0: SPI mode
1: I
2
S mode
Bit 10
I2SEN
0x0
rw
I
2
S enable
0: Disabled
1: Enabled
Bit 9: 8
OPERSEL
0x0
rw
I
2
S operation mode select
00: Slave transmission
01: Slave reception
10: Master transmission
11: Master reception
Bit 7
PCMFSSEL
0x0
rw
PCM frame synchronization
This bit is valid only when the PCM standard is used.