This register set plays an important role while initializing UART0/1 before using it. There are several parameters configured through this register such as word length, stop bit, parity enable, parity select, brake control, divisor latch access bit. The value or settings in this register configure the UART0/1 block. The Line Control Register is used to set the format of the data which is transmitted or received. If the character received is less than 8 bits, the unused MSBs are padded with zeroes.

The LSB (bit 0) represents the “oldest” received data bit. The top byte of the Rx FIFO contains the oldest character received and can be read via the bus interface. The UxRBR is the top byte of the UART0/1 Rx FIFO. UxRBR (UART 0/1 Receiver Buffer Register)

The Divisor Latch Access Bit (DLAB) in UxLCR must be zero in order to access the The top byte is the newest character in the TX FIFO and can be written via the bus interface. The UxTHR is the top byte of the UART0/1 TX FIFO. Note: x-> 0/1 (UART0/UART1) UxTHR (UART 0/1 Transmit Holding Register) Provides status information on the UART0 TX andĬontrols the operation of the UART0 Rx and TX FIFOs

Most Significant Byte of the UART baud rate generator value Least Significant Byte of the UART baud rate generator value The below table shows the registers used for UART.Ĭontrols the UART frame formatting(Number of Data Bits, Stop bits)Ĭontrols the clock pre-scaler for the baud rate generation But If you understand the UART0 obviously you can play with UART1. In this tutorial, we will see only UART0. Both UART0 & UART1 blocks internally have a 16-byte FIFO (First In First Out) structure to hold the Rx and Tx data. This includes all the pins for RS232 compatibility like flow control pins (CTS, RTS), etc. In the case of UART1, the TXD1 and RXD1 pins are P0.8 and P0.9 respectively.īoth the UART modules are identical, except the UART1 block has an additional full modem interface. In the UART0 block, the TXD0 (Transmit) and RXD0 (Receive) pins in the device are P0.0 and P0.1 respectively. Each UART block is associated with two pins, one for transmission and the other for receiving. If you are new to UART please go through our previous article about UART.Ĭoming to UART in LPC2148, the LPC214x series of MCUs have two UART blocks called UART0 and UART1.

Programming Explanation – LPC2148 Serial Communication Tutorial.

Example Calculation 2 (Baud Rate 9600 And PCLK = 30MHz).

Example Calculation 1 (Baud Rate 9600 And PCLK = 60MHz).

UxDLL & UxDLM (UART 0/1 Divisor Latch registers).

UxRBR (UART 0/1 Receiver Buffer Register).

UxTHR (UART 0/1 Transmit Holding Register).

Lpc2148 library for proteus 8