XC912BC32CFU8 Motorola Semiconductor Products, XC912BC32CFU8 Datasheet - Page 284

• Manufacturer Part Number: XC912BC32CFU8
• Description: M68HC12B Family Data Sheet
• Manufacturer: Motorola Semiconductor Products

msCAN12 Controller
16.11.5 Transmit Buffer Priority Register
16.12 Programmer’s Model of Control Registers
16.12.1 msCAN12 Module Control Register 0
Data Sheet
284
PRIO7–PRIO0— Local Priority
The programmer’s model has been laid out for maximum simplicity and efficiency.
CSWAI — CAN Stops in Wait Mode Bit
SYNCH — Synchronized Status Bit
Address: $0100
This field defines the local priority of the associated message buffer. The local
priority is used for the internal prioritization process of the msCAN12 and is
defined to be highest for the smallest binary number. The msCAN12
implements this internal prioritization mechanism:
This bit indicates whether the msCAN12 is synchronized to the CAN bus and as
such can participate in the communication process.
Address:
Reset:
Read:
Write:
Reset:
Read:
Write:
0 = The module is not affected during wait mode.
1 = The module ceases to be clocked during wait mode.
0 = msCAN12 is not synchronized to the CAN bus.
1 = msCAN12 is synchronized to the CAN bus.
–
–
–
Figure 16-16. msCAN12 Module Control Register 0 (CMCR0)
Note 1. x is 5, 6, or 7 depending on which buffer Tx0, Tx1, or Tx2, respectively.
All transmission buffers with a cleared TXE flag participate in the
prioritization right before the start of frame (SOF) is sent.
The transmission buffer with the lowest local priority field wins the
prioritization.
In case of more than one buffer having the same lowest priority, the
message buffer with the lowest index number wins.
$01xD
PRIO7
Figure 16-15. Transmit Buffer Priority Register (TBPR)
Bit 7
Bit 7
0
0
= Unimplemented
PRIO6
msCAN12 Controller
6
0
0
6
CSWAI
PRIO5
5
1
5
SYNCH
PRIO4
Unaffected by reset
4
0
4
TLNKEN
PRIO3
3
0
3
SLPAK
M68HC12B Family — Rev. 8.0
PRIO2
2
0
2
SLPRQ
PRIO1
1
0
1
MOTOROLA
SFTRES
PRIO0
Bit 0
Bit 0
1