MC68HC05X4 Datasheet, PDF (70/156 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Motorola CAN
Freescale Semiconductor, Inc.
Introduction
The MCAN includes all hardware modules necessary to implement the
CAN transfer layer, which represents the kernel of the CAN bus protocol
as defined by BOSCH GmbH, the originators of the CAN specification.
For full details of the CAN protocol please refer to the published
specifications.
Up to the message level, the MCAN is totally compatible with the full
CAN implementation. Functional differences are related to the object
layer only. Whereas a full CAN controller provides dedicated hardware
for handling a set of messages, the MCAN is restricted to receiving
and/or transmitting messages on a message by message basis.
The MCAN will never initiate an overload frame. If the MCAN starts to
receive a valid message (one that passes the acceptance filter) and
there is no receive buffer available for it then the overrun flag in the CPU
status register will be set. The MCAN will respond to overload frames
generated by other CAN nodes, as required by the CAN protocol. A
summary of all the MCAN frame formats is given in Figure 2 for
reference. A diagram of the major blocks of the MCAN is shown in
Figure 1.
MC68HC05X4
70
Motorola CAN
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