NXP Semiconductors
LPC2157/2158
Single-chip 16-bit/32-bit microcontrollers
6.12 I2C-bus serial I/O controller
The LPC2157/2158 each contain two I2C-bus controllers.
The I2C-bus is bidirectional, for inter-IC control using only two wires: a serial clock line
(SCL), and a serial data line (SDA). Each device is recognized by a unique address and
can operate as either a receiver-only device (e.g., an LCD driver or a transmitter with the
capability to both receive and send information (such as memory)). Transmitters and/or
receivers can operate in either master or slave mode, depending on whether the chip has
to initiate a data transfer or is only addressed. The I2C-bus is a multi-master bus, it can be
controlled by more than one bus master connected to it.
The I2C-bus implemented in LPC2157/2158 supports bit rates up to 400 kbit/s (Fast
I2C-bus).
6.12.1 Features
• Compliant with standard I2C-bus interface.
• Easy to configure as master, slave, or master/slave.
• Programmable clocks allow versatile rate control.
• Bidirectional data transfer between masters and slaves.
• Multi-master bus (no central master).
• Arbitration between simultaneously transmitting masters without corruption of serial
data on the bus.
• Serial clock synchronization allows devices with different bit rates to communicate via
one serial bus.
• Serial clock synchronization can be used as a handshake mechanism to suspend and
resume serial transfer.
• The I2C-bus can be used for test and diagnostic purposes.
6.13 SPI serial I/O controller
The LPC2157/2158 each contain one SPI controller. The 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 a byte of data to the slave, and
the slave always sends a byte of data to the master.
6.13.1 Features
• 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.
6.14 SSP serial I/O controller
The LPC2157/2158 each contain one Serial Synchronous Port controller (SSP). 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. However, only a single master and a single
LPC2157_2158_1
Product data sheet
Rev. 01 — 15 October 2008
© NXP B.V. 2008. All rights reserved.
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