This device has five UART modules. The CPU accesses data, control, and status information. The UART also supports µDMA transfers. Each UART performs functions of parallel-to-serial and serial-to-parallel conversions. Each of the five UART modules is similar in functionality to a 16C550 UART, but is not register-compatible.
The UART is configured for transmit and receive through the TXE bit and the RXE bit, respectively, of the UART Control (UARTCTL) register. Transmit and receive are both enabled out of reset. Before any control registers are programmed, the UART must be disabled by clearing the UARTEN bit in UARTCTL. If the UART is disabled during a TX or RX operation, the current transaction is completed before the UART stops.
The UART module also includes a serial IR (SIR) encoder/decoder block that can be connected to an infrared transceiver to implement an IrDA SIR physical layer. The SIR function is programmed using the UARTCTL register.
Figure 5-31 shows the UART peripheral.