Motorola MCF5281 ユーザーズマニュアル

MOTOROLA

C Interface  

24-1

This chapter describes the MCF5282MCF523x I

2

C module, including I

2

C protocol, clock

synchronization, and I

2

C programming model registers. It also provides extensive

programming examples.

I

2

C is a two-wire, bidirectional serial bus that provides a simple, efficient method of data

exchange, minimizing the interconnection between devices. This bus is suitable for
applications that require occasional communication between many devices over a short
distance. The flexible I

2

C bus allows additional devices to be connected to the bus for

expansion and system development.

The I

2

C 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.

The I

2

C module has the following key features:

• Compatibility with I

2

C bus standard version 2.1

• Support for 3.3V 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