MC68HC08AZ60 Datasheet, PDF (334/452 Pages) Motorola, Inc – Advance Information

Freescale Semiconductor, Inc.
MSCAN Controller (MSCAN08)
Transmit Buffer
Priority Registers
Address: $05bD
Bit 7
6
5
4
3
2
1
Read:
PRIO7
Write:
PRIO6
PRIO5
PRIO4
PRIO3
PRIO2
PRIO1
Reset: u
u
u
u
u
u
u
Figure 13. Transmit Buffer Priority Register (TBPR)
Bit 0
PRIO0
u
PRIO7–PRIO0 — Local Priority
This field defines the local priority of the associated message buffer.
The local priority is used for the internal priorization process of the
MSCAN08 and is defined to be highest for the smallest binary
number. The MSCAN08 implements the following internal priorization
mechanism:
• All transmission buffers with a cleared TXE flag participate in the
priorization right before the SOF is sent.
• The transmission buffer with the lowest local priority field wins the
priorization.
• In case more than one buffer has the same lowest priority, the
message buffer with the lower index number wins.
Programmer’s Model of Control Registers
The programmer’s model has been laid out for maximum simplicity and
efficiency. Figure 14 gives an overview on the control register block of
the MSCAN08.
MC68HC08AZ60 — Rev 1.0
334
MSCAN Controller (MSCAN08)
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30-mscan
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