MC68HC08AZ32A Datasheet, PDF (327/456 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
MSCAN08 Controller (MSCAN08)
Message Storage
When the MSCAN08 module is transmitting, the MSCAN08 receives its
own messages into the background receive buffer, RxBG. It does NOT
overwrite RxFG, generate a receive interrupt or acknowledge its own
messages on the CAN bus. The exception to this rule is in loop-back
mode (see MSCAN08 Module Control Register 1 on page 357), where
the MSCAN08 treats its own messages exactly like all other incoming
messages. The MSCAN08 receives its own transmitted messages in the
event that it loses arbitration. If arbitration is lost, the MSCAN08 must be
prepared to become receiver.
An overrun condition occurs when both the foreground and the
background receive message buffers are filled with correctly received
messages with accepted identifiers and another message is correctly
received from the bus with an accepted identifier. The latter message will
be discarded and an error interrupt with overrun indication will be
generated if enabled. The MSCAN08 is still able to transmit messages
with both receive message buffers filled, but all incoming messages are
discarded.
MC68HC08AZ32A — Rev 1.0
MOTOROLA
MSCAN08 Controller (MSCAN08)
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Technical Data
327