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UM10375
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2011. All rights reserved.
User manual
Rev. 3 — 14 June 2011
207 of 368
13.1 How to read this chapter
The I
2
C-bus block is identical for all LPC13xx parts.
13.2 Basic configuration
The I
2
C-bus interface is configured using the following registers:
1. Pins: The I2C pin functions and the I2C mode are configured in the IOCONFIG
register block (
and
).
2. Power and peripheral clock: In the SYSAHBCLKCTRL register, set bit 5 (
3. Reset: Before accessing the I2C block, ensure that the I2C_RST_N bit (bit 1) in the
PRESETCTRL register (
) is set to 1. This de-asserts the reset signal to the I2C
block.
13.3 Features
•
Standard I
2
C-compliant bus interfaces may be configured as Master, Slave, or
Master/Slave.
•
Arbitration is handled between simultaneously transmitting masters without corruption
of serial data on the bus.
•
Programmable clock allows adjustment of I
2
C transfer rates.
•
Data transfer is bidirectional between masters and slaves.
•
Serial clock synchronization allows devices with different bit rates to communicate via
one serial bus.
•
Serial clock synchronization is used as a handshake mechanism to suspend and
resume serial transfer.
•
Supports Fast-mode Plus.
•
Optional recognition of up to four distinct slave addresses.
•
Monitor mode allows observing all I
2
C-bus traffic, regardless of slave address.
•
I
2
C-bus can be used for test and diagnostic purposes.
•
The I
2
C-bus contains a standard I
2
C-compliant bus interface with two pins.
13.4 Applications
Interfaces to external I
2
C standard parts, such as serial RAMs, LCDs, tone generators,
other microcontrollers, etc.
13.5 General description
A typical I
2
C-bus configuration is shown in
. Depending on the state of the
direction bit (R/W), two types of data transfers are possible on the I
2
C-bus:
UM10375
Chapter 13: LPC13xx I2C-bus controller
Rev. 3 — 14 June 2011
User manual