I2C Interface
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 25-3
The interface operates up to 100 Kbps with maximum bus loading and timing. The device is capable of
operating at higher baud rates, up to a maximum of the internal bus clock divided by 20, with reduced bus
loading. The maximum communication length and the number of devices connected are limited by a
maximum bus capacitance of 400 pF.
The I2C system is a true multiple-master bus; it uses arbitration and collision detection to prevent data
corruption in the event that multiple devices attempt to control the bus simultaneously. This feature
supports complex applications with multiprocessor control and can be used for rapid testing and alignment
of end products through external connections to an assembly-line computer.
NOTE
The I2C module is compatible with the Philips I2C bus protocol. For
information on system configuration, protocol, and restrictions, see The I2C
Bus Specification, Version 2.1.
NOTE
The GPIO module must be configured to enable the peripheral function of
the appropriate pins (refer to Chapter 13, “General Purpose I/O Module”)
prior to configuring the I2C module.

25.1.3 Features

The I2C module has these key features:
Compatibility with I2C bus standard version 2.1
Support for 3.3-V tolerant devices
Multiple-master operation
Software-programmable for one of 50 different serial clock frequencies
Software-selectable acknowledge bit
Interrupt-driven, byte-by-byte data transfer
Arbitration-lost interrupt with automatic mode switching from master to slave
Calling address identification interrupt
START and STOP signal generation/detection
Repeated START signal generation
Acknowledge bit generation/detection
Bus-busy detection

25.2 Memory Map/Register Definition

The below table lists the configuration registers used in the I2C interfaces.