Register Descriptions
1464
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
M3 Universal Asynchronous Receivers/Transmitters (UARTs)
WRITE-ONLY Error Clear Register
Figure 21-9. UART Receive Status/Error Clear Register (UARTRSR/UARTECR)
31
8
7
0
Reserved
DATA
W-0
W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 21-4. UART Error Clear (UARTECR) Register Field Descriptions
Bit
Field
Value
Description
31-8
Reserved
Reserved
7-0
DATA
Error Clear
A write to this register of any data clears the framing, parity, break, and overrun flags.
21.7.3 UART Flag Register (UARTFR), offset 0x018
The UARTFR register is the flag register. After reset, the TXFF, RXFF, and BUSY bits are 0, and TXFE
and RXFE bits are 1.
Figure 21-10. UART Flag Register (UARTFR)
31
16
Reserved
R-0
15
8
7
6
5
4
3
2
0
Reserved
TXFE
RXFF
TXFF
RXFE
BUSY
Reserved
R-0
R-1
R-0
R-0
R-1
R-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 21-5. UART Flag Register (UARTFR) Field Descriptions
Bit
Field
Value
Description
31-8
Reserved
Reserved
7
TXFE
UART Transmit FIFO Empty
The meaning of this bit depends on the state of the FEN bit in the UARTLCRH register.
0
The transmitter has data to transmit.
1
If the FIFO is disabled (FEN is 0), the transmit holding register is empty.
If the FIFO is enabled (FEN is 1), the transmit FIFO is empty.
6
RXFF
UART Receive FIFO Full
The meaning of this bit depends on the state of the FEN bit in the UARTLCRH register.
0
The receiver can receive data.
1
If the FIFO is disabled (FEN is 0), the receive holding register is full.
If the FIFO is enabled (FEN is 1), the receive FIFO is full.
5
TXFF
UART Transmit FIFO Full
The meaning of this bit depends on the state of the FEN bit in the UARTLCRH register.
0
The transmitter is not full.
1
If the FIFO is disabled (FEN is 0), the transmit holding register is full.
If the FIFO is enabled (FEN is 1), the transmit FIFO is full.
4
RXFE
UART Receive FIFO Empty
The meaning of this bit depends on the state of the FEN bit in the UARTLCRH register.
0
The receiver is not empty.
1
If the FIFO is disabled (FEN is 0), the receive holding register is empty.
If the FIFO is enabled (FEN is 1), the receive FIFO is empty.