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MPC555 / MPC556
CAN 2.0B CONTROLLER MODULE
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
16-1
SECTION 16
CAN 2.0B CONTROLLER MODULE
The MPC555 / MPC556 contains two CAN 2.0B controller modules (TouCAN). Each
TouCAN is a communication controller that implements the controller area network
(CAN) protocol, an asynchronous communications protocol used in automotive and in-
dustrial control systems. It is a high speed (1 Mbit/sec), short distance, priority based
protocol that can run over a variety of mediums (for example, fiber optic cable or an
unshielded twisted pair of wires). The TouCAN supports both the standard and extend-
ed identifier (ID) message formats specified in the CAN protocol specification, revision
2.0, part B.
Each TouCAN module contains 16 message buffers, which are used for transmit and
receive functions. It also contains message filters, which are used to qualify the re-
ceived message IDs when comparing them to the receive buffer identifiers.
shows a block diagram of a TouCAN module.
Figure 16-1 TouCAN Block Diagram
16.1 Features
Each TouCAN module provides these features:
• Full implementation of CAN protocol specification, version 2.0 A/B
— Standard data and remote frames (up to 109 bits long)
Control
Slave Bus
CNTX0
CNRX0
Interface Unit
16Rx/Tx
Message
Buffers
Transmitter
Receiver
CNTX1
1
CNRX1
1
IMB
1. In the MPC555 / MPC556, the CNTX1 and CNRX1 signals are not available.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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