UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
948 of 1269
37.1 How to read this chapter
The USART0/2/3 controllers are available on all LPC43xx parts.
37.2 Basic configuration
The USART0/2/3 are configured as follows:
•
See
for clocking and power control.
•
The USART0/2/3 are reset by the UART0/2/3_RST (reset #44/46/47).
•
The USART0/2/3 interrupts are connected to slots # 24/26/27 in the NVIC.
•
For connecting the USART0/2/3 receive and transmit lines to the GPDMA, use the
DMAMUX register in the CREG block (see
) and enable the GPDMA channel
in the DMA Channel Configuration registers (
).
•
The internal USART transmit/receive active signals (USARTx TX/RX) are connected
to the GIMA (see
). These signals are driven when data are transmitted or
received and can be used to trigger any of the timers or the SCT.
•
In synchronous mode, set the clock frequency on pin U0/2/3_UCLK to
6
BASE_UART0/2/3_CLK.
37.3 Features
•
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.
•
UART mode allows for implementation of either software or hardware flow control.
•
RS-485/EIA-485 9-bit mode support with output enable.
•
Support for synchronous mode UART (USART).
•
IrDA interface (USART3 only).
•
DMA support.
UM10503
Chapter 37: LPC43xx USART0_2_3
Rev. 1.3 — 6 July 2012
User manual
Table 819. USART0/2/3 clocking and power control
Base clock
Branch clock
Operating
frequency
USART0 clock to register interface
BASE_M4_CLK
CLK_M4_UART0
up to 204 MHz
USART0 peripheral clock (PCLK)
BASE_UART0_CLK
CLK_APB0_UART0 up to 204 MHz
USART2 clock to register interface
BASE_M4_CLK
CLK_M4_UART2
up to 204 MHz
USART2 peripheral clock (PCLK)
BASE_UART2_CLK
CLK_APB2_UART2 up to 204 MHz
USART3 clock to register interface
BASE_M4_CLK
CLK_M4_UART3
up to 204 MHz
USART3 peripheral clock (PCLK)
BASE_UART3_CLK
CLK_APB2_UART3 up to 204 MHz