Register 3: UART Flag (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.
Note:
Registers that contain bits for modem control or status only apply to the following UARTs:
■ UART0 (modem flow control and modem status)
■ UART1 (modem flow control and modem status)
■ UART2 (modem flow control)
■ UART3 (modem flow control)
■ UART4 (modem flow control)
UART Flag (UARTFR)
UART0 base: 0x4000.C000
UART1 base: 0x4000.D000
UART2 base: 0x4000.E000
UART3 base: 0x4000.F000
UART4 base: 0x4001.0000
UART5 base: 0x4001.1000
UART6 base: 0x4001.2000
UART7 base: 0x4001.3000
Offset 0x018
Type RO, reset 0x0000.0090
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
reserved
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Type
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reset
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
CTS
DSR
DCD
BUSY
RXFE
TXFF
RXFF
TXFE
RI
reserved
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Type
0
0
0
0
1
0
0
1
0
0
0
0
0
0
0
0
Reset
Description
Reset
Type
Name
Bit/Field
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
0x0000.00
RO
reserved
31:9
Ring Indicator
Description
Value
The
UnRI
signal is not asserted.
0
The
UnRI
signal is asserted.
1
0
RO
RI
8
June 18, 2014
1180
Texas Instruments-Production Data
Universal Asynchronous Receivers/Transmitters (UARTs)