NXP Semiconductors
LPC1769/68/67/66/65/64/63
32-bit ARM Cortex-M3 microcontroller
7.16 UARTs
The LPC17xx each contain four UARTs. In addition to standard transmit and receive data
lines, UART1 also provides a full modem control handshake interface and support for
RS-485/9-bit mode allowing both software address detection and automatic address
detection using 9-bit mode.
The UARTs include a fractional baud rate generator. Standard baud rates such as
115200 Bd can be achieved with any crystal frequency above 2 MHz.
7.16.1 Features
• Maximum UART data bit rate of 6.25 Mbit/s.
• 16 B Receive and Transmit FIFOs.
• Register locations conform to 16C550 industry standard.
• Receiver FIFO trigger points at 1 B, 4 B, 8 B, and 14 B.
• Built-in fractional baud rate generator covering wide range of baud rates without a
need for external crystals of particular values.
• Auto baud capabilities and FIFO control mechanism that enables software flow
control implementation.
• UART1 equipped with standard modem interface signals. This module also provides
full support for hardware flow control (auto-CTS/RTS).
• Support for RS-485/9-bit/EIA-485 mode (UART1).
• UART3 includes an IrDA mode to support infrared communication.
• All UARTs have DMA support.
7.17 SPI serial I/O controller
The LPC17xx contain one SPI controller. SPI is a full duplex serial interface designed to
handle multiple masters and slaves connected to a given bus. Only a single master and a
single slave can communicate on the interface during a given data transfer. During a data
transfer the master always sends 8 bits to 16 bits of data to the slave, and the slave
always sends 8 bits to 16 bits of data to the master.
7.17.1 Features
• Maximum SPI data bit rate of 12.5 Mbit/s
• Compliant with SPI specification
• Synchronous, serial, full duplex communication
• Combined SPI master and slave
• Maximum data bit rate of one eighth of the input clock rate
• 8 bits to 16 bits per transfer
7.18 SSP serial I/O controller
The LPC17xx contain two SSP controllers. The SSP controller is capable of operation on
a SPI, 4-wire SSI, or Microwire bus. It can interact with multiple masters and slaves on the
bus. Only a single master and a single slave can communicate on the bus during a given
LPC1769_68_67_66_65_64_63
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 7 — 5 April 2011
© NXP B.V. 2011. All rights reserved.
27 of 79