LM3S2637 Datasheet, PDF (443/678 Pages) Texas Instruments – Stellaris® LM3S2637 Microcontroller

Stellaris^® LM3S2637 Microcontroller
Register 8: UART Control (UARTCTL), offset 0x030
The UARTCTL register is the control register. All the bits are cleared on reset except for the
Transmit Enable (TXE) and Receive Enable (RXE) bits, which are set to 1.
To enable the UART module, the UARTEN bit must be set to 1. If software requires a configuration
change in the module, the UARTEN bit must be cleared before the configuration changes are written.
If the UART is disabled during a transmit or receive operation, the current transaction is completed
prior to the UART stopping.
Note: The UARTCTL register should not be changed while the UART is enabled or else the results
are unpredictable. The following sequence is recommended for making changes to the
UARTCTL register.
1. Disable the UART.
2. Wait for the end of transmission or reception of the current character.
3. Flush the transmit FIFO by disabling bit 4 (FEN) in the line control register (UARTLCRH).
4. Reprogram the control register.
5. Enable the UART.
UART Control (UARTCTL)
UART0 base: 0x4000.C000
UART1 base: 0x4000.D000
Offset 0x030
Type R/W, reset 0x0000.0300
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
reserved
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
reserved
RXE
TXE
LBE
reserved
SIRLP SIREN UARTEN
Type RO
RO
RO
RO
RO
RO
R/W
R/W
R/W
RO
RO
RO
RO
R/W
R/W
R/W
Reset
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
Bit/Field
31:10
9
8
Name
reserved
RXE
TXE
Type
RO
R/W
R/W
Reset
0
1
1
Description
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.
UART Receive Enable
If this bit is set to 1, the receive section of the UART is enabled. When
the UART is disabled in the middle of a receive, it completes the current
character before stopping.
Note: To enable reception, the UARTEN bit must also be set.
UART Transmit Enable
If this bit is set to 1, the transmit section of the UART is enabled. When
the UART is disabled in the middle of a transmission, it completes the
current character before stopping.
Note: To enable transmission, the UARTEN bit must also be set.
June 18, 2012
443
Texas Instruments-Production Data