MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 285

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

23.12.4 Data Segment Registers (DSRn)
The eight data segment registers contain the data to be transmitted or received. The number of bytes to
be transmitted or being received is determined by the data length code in the corresponding DLR.
23.12.5 Transmit Buffer Priority Registers
PRIO7–PRIO0 — Local Priority
Freescale Semiconductor
This field defines the local priority of the associated message buffer. The local priority is used for the
internal prioritisation process of the MSCAN08 and is defined to be highest for the smallest binary
number. The MSCAN08 implements the following internal prioritisation mechanism:
•
•
•
All transmission buffers with a cleared TXE flag participate in the prioritisation right before the SOF
is sent.
The transmission buffer with the lowest local priority field wins the prioritisation.
In case more than one buffer has the same lowest priority, the message buffer with the lower index
number wins.
Address:
Reset:
Read:
Write:
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
Figure 23-13. Transmit Buffer Priority Register (TBPR)
$05bD
PRIO7
Bit 7
PRIO6
6
PRIO5
5
Unaffected by Reset
PRIO4
4
PRIO3
3
Programmer’s Model of Message Storage
PRIO2
2
PRIO1
1
PRIO0
Bit 0
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