AT32F425
Series Reference Manual
2022.03.30
Page 157
Ver 2.01
Bit 4
IDLEF
0
ro
Idle flag
This bit is set by hardware when an idle line is detected. It
is cleared by software. (Read USART_DT register followed
by a USART_DT read operation)
0: No idle line is detected.
1: Idle line is detected.
Bit 3
ROERR
0
ro
Receiver overflow error
This bit is set by hardware when the data is received while
the RDNE is still set. It is cleared by software. (Read
USART_STS register followed by a USART_DT read
operation)
0: No overflow error
1: Overflow error is detected.
Note: When this bit iset, the DT regiter content will not be
lost, but the subsequent data will be overwritten.
Bit 2
NERR
0
ro
Noise error
This bit is set by hardware when noise is detect on a
received frame. It is cleared by software. (Read
USART_STS register followed by a USART_DT read
operation)
0: No noise is detected.
1: Noise is detected.
Bit 1
FERR
0
ro
Framing error
This bit is set by hardware when a stop bit error (low),
excessive noise or break frame is detected. It is cleared by
software. USART_STS register followed by a USART_DT
read operation)
0: No framing error is detected.
1: Framing error is detected.
Bit 0
PERR
0
ro
Parity error
This bit is set by hardware when parity error occurs. It is
cleared by software. USART_STS register followed by a
USART_DT read operation)
0: No parity error occurs.
1: Parity error occurs.
12.12.2 Data register (USART_DT)
Bit
Register
Reset value
Type
Description
Bit 31: 9
Reserved
0x000000
resd
Kept at its default value.
Bit 8: 0
DT
0x000
rw
Data value
This register provides read and write function. When
transmitting with the parity bit enabled, the value written in
the MSB bit will be replaced by the parity bit. When
receiving with the parity bit enabled, the value in the MSB
bit is the received parity bit.
12.12.3 Baud rate register (USART_BAUDR)
Note: If the TE or RE is disabled respectively, the baud counter stops counting.
Bit
Register
Reset value
Type
Description
Bit 31: 16 Reserved
0x0000
resd
Kept at its default value.
Bit 15: 0
DIV
0x0000
rw
Divider
This field define the USART divider.
12.12.4 Control register1 (USART_CTRL1)
Bit
Register
Reset value
Type
Description
Bit 31: 29 Reserved
0x0
resd
Kept at its default value.
Bit 28
DBN1
0x0
rw
Data bit num
This bit, along with the DBN0 bit, is used to program the
number of data bits.
10: 7 data bits
00: 8 data bits
01: 9 data bits