Chapter 25

FlexCAN

The FlexCAN module is a communication controller implementing the controller area network (CAN) protocol, an asynchronous communications protocol used in automotive and industrial control systems. It is a high speed (1 Mbit/sec), short distance, priority based protocol which can communicate using a variety of mediums (for example, fiber optic cable or an unshielded twisted pair of wires). The FlexCAN supports both the standard and extended identifier (ID) message formats specified in the CAN protocol specification, revision 2.0, part B.

The CAN protocol was primarily, but not only, designed to be used as a vehicle serial data bus, meeting the specific requirements of this field: real-time processing, reliable operation in the EMI environment of a vehicle, cost-effectiveness and required bandwidth. A general working knowledge of the CAN protocol revision 2.0 is assumed in this document. For details, refer to the CAN protocol revision 2.0 specification.

25.1 Features

Based on and includes all existing Motorola TouCAN module features

Motorola IP interface architecture

Full implementation of the CAN protocol specification version 2.0

Standard data and remote frames (up to 109 bits long)

Extended data and remote frames (up to 127 bits long)

0–8 bytes data length

Programmable bit rate up to 1Mbit/sec

Up to 16 flexible message buffers of 0–8 bytes data length, each configurable as Rx or Tx, all supporting standard and extended messages

Listen-only mode capability

Content-related addressing

No read/write semaphores

Three programmable mask registers: global (for MBs 0-13), special for MB14, and special for MB15

Programmable transmit-first scheme: lowest ID or lowest buffer number

MOTOROLA

Chapter 25. FlexCAN

25-1

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Motorola MCF5281, MCF5282 user manual Chapter FlexCAN