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Field
Name
R/W
Description
15:4
IBR
R/W
Integer of USART Baud Rate Divider factor
The integral part of USART baud rate division factor is determined by these
12 bits.
31:16
Reserved
Receive timeout register (USART_RXTO)
Offset address: 0x14
Reset value: 0x0000
Field
Name
R/W
Description
23:0
RXTO
R/W
Receiver Timeout Value Setup
This bit field specifies the receive timeout value in baud clock.
In standard mode, after the last byte is received, if no new start bit is
detected within the duration of RXTO value, RXTOFLG will be set by
hardware.
In smart card mode, this value is used to realize CWT and BWT. In this
mode, start timeout measurement from the start bit of the last byte.
31:24
Reserved
Request register (USART_REQUEST)
Offset address: 0x18
Reset value: 0x0000
Field
Name
R/W
Description
0
ABRDQ
W
Auto Baud Rate Detection Request
Set this bit, the ABRDFLG flag will be cleared and an automatic baud rate
detection will be conducted when the data is received next time.
1
TXBFQ
W
Transmit Break Frame Request
Set this bit, TXBFFLG flag will be set and a break frame will be transmitted
after the transmission state machine is enabled.
2
MUTEQ
W
Mute Mode Request
Set this bit to enter the mute mode and RXWFMUTE flag will be cleared.
3
RXDFQ
W
Receive Data Flush Request
Set this bit and RXBNEFLG flag will be cleared.
The data that has not been read out in the receive register can be discarded to
avoid overrun error.
31:4
Reserved
Interrupt and state register (USART_STS)
Offset address: 0x1C
Reset value: 0x0200 00C0
Field
Name
R/W
Description
0
PEFLG
R
Parity Error Occur Flag
0: No error
1: Parity error is detected
In receiving mode, when a parity error occurs, it is set to 1 by
hardware; set PECLR and this bit can be cleared.
1
FEFLG
R
Frame Error Occur Flag
0: No frame error
1: Frame error or break symbol is detected