LPC540xx
NXP Semiconductors
32-bit ARM Cortex-M4 microcontroller
7.14.8.4 USART
Features
• Maximum bit rates of 6.25 Mbit/s in asynchronous mode.
• The maximum supported bit rate for USART master synchronous mode is 24 Mbit/s,
and the maximum supported bit rate for USART slave synchronous mode is
12.5 Mbit/s.
• 7, 8, or 9 data bits and 1 or 2 stop bits.
• Synchronous mode with master or slave operation. Includes data phase selection and
continuous clock option.
• Multiprocessor/multidrop (9-bit) mode with software address compare.
• RS-485 transceiver output enable.
• Autobaud mode for automatic baud rate detection
• Parity generation and checking: odd, even, or none.
• Software selectable oversampling from 5 to 16 clocks in asynchronous mode.
• One transmit and one receive data buffer.
• RTS/CTS for hardware signaling for automatic flow control. Software flow control can
be performed using Delta CTS detect, Transmit Disable control, and any GPIO as an
RTS output.
• Received data and status can optionally be read from a single register
• Break generation and detection.
• Receive data is 2 of 3 sample "voting". Status flag set when one sample differs.
• Built-in Baud Rate Generator with auto-baud function.
• A fractional rate divider is shared among all USARTs.
• Interrupts available for Receiver Ready, Transmitter Ready, Receiver Idle, change in
receiver break detect, Framing error, Parity error, Overrun, Underrun, Delta CTS
detect, and receiver sample noise detected.
• Loopback mode for testing of data and flow control.
• In synchronous slave mode, wakes up the part from deep-sleep mode.
• Special operating mode allows operation at up to 9600 baud using the 32.768 kHz
RTC oscillator as the UART clock. This mode can be used while the device is in
deep-sleep mode and can wake-up the device when a character is received.
• USART transmit and receive functions work with the system DMA controller.
7.14.8.5 I2S-bus interface
The I2S bus provides a standard communication interface for streaming data transfer
applications such as digital audio or data collection. The I2S bus specification defines a
3-wire serial bus, having one data, one clock, and one word select/frame trigger signal,
providing single or dual (mono or stereo) audio data transfer as well as other
configurations. In the LPC540xx, the I2S function is included in Flexcomm Interface 6 and
Flexcomm Interface 7. Each of the Flexcomm Interface implements four I2S channel pairs.
The I2S interface within one Flexcomm Interface provides at least one channel pair that
can be configured as a master or a slave. Other channel pairs, if present, always operate
as slaves. All of the channel pairs within one Flexcomm Interface share one set of I2S
LPC540xx
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2018. All rights reserved.
Product data sheet
Rev. 1.8 — 22 June 2018
74 of 168
NXP [ NXP ]
