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 enable the UART module, the UARTEN bit must be set. 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: 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)
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 clearing 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
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 0x030
Type RW, reset 0x0000.0300
16171819202122232425262728293031
reserved
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
UARTENSIRENSIRLPSMARTEOTHSEreservedLBETXERXEDTRRTSreservedRTSENCTSEN
RWRWRWRWRWRWRORWRWRWRWRWRORORWRWType
0000000011000000Reset
June 18, 20141188
Texas Instruments-Production Data
Universal Asynchronous Receivers/Transmitters (UARTs)