Freescale Semiconductor MPC5604B - Introduction

MPC5604B/C Microcontroller Reference Manual, Rev. 8
Freescale Semiconductor 423
Chapter 22
FlexCAN
22.1 Introduction
The FlexCAN module is a communication controller implementing the CAN protocol according to the
CAN 2.0B protocol specification. A general block diagram is shown in Figure 22-1, which describes the
main sub-blocks implemented in the FlexCAN module, including two embedded memories, one for
storing Message Buffers (MB) and another one for storing Rx Individual Mask Registers. Support for up
to 64 Message Buffers is provided. The functions of the submodules are described in subsequent sections.
Figure 22-1. FlexCAN block diagram
22.1.1 Overview
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. The FlexCAN module is a full implementation of the
CAN protocol specification, version 2.0 B, which supports both standard and extended message frames.
288/544/1056-
Bus Interface Unit
max MB #
(0–63)
IP Bus Interface
CAN
Message
CAN Tx
CAN Rx
MB1
MB0
MB62
MB63
Clocks, Address & Data buses,
Interrupt and Test Signals
Buffer
Management
Protocol
Interface
byte SRAM
Message
Buffer
Storage
64/128/256-
RXIMR1
RXIMR0
RXIMR62
RXIMR63
byte SRAM
ID Mask
Storage