
DR
AFT
DR
AFT
DRAFT
DR
D
RAFT
DRAFT
DRA
FT DRAF
D
RAFT DRAFT DRAFT DRAFT DRAFT D
DRAFT
D
RAFT DRA
FT DRAFT DRAFT DRAFT DRA
UM10360_0
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 00.06 — 5 June 2009
291 of 808
1.
Basic configuration
The UART1 peripheral is configured using the following registers:
1. Power: In the PCONP register (
), set bits PCUART1.
Remark:
On reset, UART1 is enabled (PCUART1 = 1).
2. Peripheral clock: In the PCLKSEL0 register (
), select PCLK_UART1.
3. Baud rate: In register U1LCR (
), set bit DLAB =1. This enables access
to registers DLL (
) and DLM (
) for setting the baud rate.
Also, if needed, set the fractional baud rate in the fractional divider register
(
4. UART FIFO: Use bit FIFO enable (bit 0) in register U0FCR (
) to enable
FIFO.
5. Pins: Select UART pins through PINSEL registers and pin modes through the
PINMODE registers (
Remark:
UART receive pins should not have pull-down resistors enabled.
6. Interrupts: To enable UART interrupts set bit DLAB =0 in register U1LCR
(
). This enables access to U1IER (
). Interrupts are enabled
in the NVIC using the appropriate Interrupt Set Enable register.
7. DMA: UART1 transmit and receive functions can operated with the GPDMA controller
).
2.
Features
•
UART1 is identical to UART0/2/3, with the addition of a modem interface and
RS-485/EIA-485 modes, no IrDA support.
•
16 byte Receive and Transmit FIFOs.
•
Register locations conform to ‘550 industry standard.
•
Receiver FIFO trigger points at 1, 4, 8, and 14 bytes.
•
Built-in baud rate generator.
•
Standard modem interface signals included (CTS, DCD, DTS, DTR, RI, RTS).
(UART1 only)
•
UART1 allows for implementation of either software or hardware flow control.
•
RS-485/EIA-485 9-bit mode support with output enable. (UART1 only)
•
DMA support for both transmit and receive.
UM10360
Chapter 15: LPC17xx UART1
Rev. 00.06 — 5 June 2009
User manual