MC68HC08AZ16 Datasheet, PDF (372/527 Pages) Motorola, Inc – HCMOS Microcontroller Unit

msCAN08 Controller (msCAN08)
Programmer’s model of message storage
ProgrammerÕs model of message storage
The following section details the organisation of the receive and transmit
message buffers and the associated control registers. For reasons of
programmer interface simplification the receive and transmit message
buffers have the same outline. Each message buffer allocates 16 byte in
the memory map containing a 13 byte data structure. An additional
Transmit Buffer Priority Register (TBPR) is defined for the transmit
buffers.
Addr
Register Name
xxb0
xxb1
Identifier Register 0
Identifier Register 1
xxb2
Identifier Register 2
xxb3
xxb4
Identifier Register 3
Data Segment Register 0
xxb5
xxb6
xxb7
Data Segment Register 1
Data Segment Register 2
Data Segment Register 3
xxb8
xxb9
Data Segment Register 4
Data Segment Register 5
xxbA
Data Segment Register 6
xxbB
xxbC
xxbD
Data Segment Register 7
Data Length Register
Transmit Buffer Priority Register⁽¹⁾
xxbE
xxbF
unused
unused
Figure 10. Message Buffer organisation
1. Not Applicable for Receive Buffers
Message Buffer
outline
Figure 11 shows the common 13 byte data structure of receive and
transmit buffers for extended identifiers. The mapping of standard
identifiers into the IDR registers is shown in Figure 12. All bits of the 13
byte data structure are undefined out of reset.
25-can
MOTOROLA
msCAN08 Controller (msCAN08)
MC68HC08AZ32
371