Freescale Semiconductor Demonstration Board for Freescale MC9S12XHY256 Microcontroller DEMO9S12XHY256 DEMO9S12XHY256 用户手册

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Freescale Semiconductor

The synchronization jump width (see the Bosch CAN 2.0A/B specification for details) can be programmed
in a range of 1 to 4 time quanta by setting the SJW parameter.

The SYNC_SEG, TSEG1, TSEG2, and SJW parameters are set by programming the MSCAN bus timing
registers (CANBTR0, CANBTR1) (see

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and

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gives an overview of the Bosch CAN 2.0A/B specification compliant segment settings and the

related parameter values.

It is the user’s responsibility to ensure the bit time settings are in compliance
with the CAN standard.

The MSCAN module behaves as described within this specification in all normal system operating modes.
Write restrictions exist for some registers.

SYNC_SEG

System expects transitions to occur on the CAN bus during this
period.

Transmit Point

A node in transmit mode transfers a new value to the CAN bus at
this point.

Sample Point

A node in receive mode samples the CAN bus at this point. If the
three samples per bit option is selected, then this point marks the
position of the third sample.

5 .. 10

4 .. 9

2

1

1 .. 2

0 .. 1

4 .. 11

3 .. 10

3

2

1 .. 3

0 .. 2

5 .. 12

4 .. 11

4

3

1 .. 4

0 .. 3

6 .. 13

5 .. 12

5

4

1 .. 4

0 .. 3

7 .. 14

6 .. 13

6

5

1 .. 4

0 .. 3

8 .. 15

7 .. 14

7

6

1 .. 4

0 .. 3

9 .. 16

8 .. 15

8

7

1 .. 4

0 .. 3