MC68HC908GZ8 FREESCALE [Freescale Semiconductor, Inc], MC68HC908GZ8 Datasheet - Page 135

• Manufacturer Part Number: MC68HC908GZ8
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

The synchronization jump width (SJW) can be programmed in a range of 1 to 4 time quanta by setting the
SJW parameter.
The above parameters can be set by programming the bus timing registers, CBTR0 and CBTR1. See
12.13.3 MSCAN08 Bus Timing Register 0
Table 12-8
Freescale Semiconductor
gives an overview on the CAN conforming segment settings and the related parameter values.
SYNC_SEG
Transmit point
Sample point
Segment 1
It is the user’s responsibility to make sure that the bit timing settings are in
compliance with the CAN standard,
5 .. 10
4 .. 11
5 .. 12
6 .. 13
7 .. 14
8 .. 15
9 .. 16
Time
Table 12-4. CAN Standard Compliant Bit Time Segment Settings
SYNC
_SEG
1
System expects transitions to occur on the bus during this period.
A node in transmit mode will transfer a new value to the CAN bus at this point.
A node in receive mode will sample the bus at this point. If the three samples
per bit option is selected then this point marks the position of the third sample.
MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 4
Figure 12-9. Segments Within the Bit Time
TSEG1
3 .. 10
4 .. 11
5 .. 12
6 .. 13
7 .. 14
8 .. 15
4 .. 9
Table 12-3. Time Segment Syntax
NRZ SIGNAL
(PROP_SEG + PHASE_SEG1)
8... 25 TIME QUANTA
TIME SEGMENT 1
= 1 BIT TIME
Segment 2
and
4 ... 16
Time
2
3
4
5
6
7
8
12.13.4 MSCAN08 Bus Timing Register
NOTE
TSEG2
1
2
3
4
5
6
7
SAMPLE POINT
(SINGLE OR TRIPLE SAMPLING)
(PHASE_SEG2)
Synchronized
TIME SEG. 2
Jump Width
2 ... 8
1 .. 2
1 .. 3
1 .. 4
1 .. 4
1 .. 4
1 .. 4
1 .. 4
0 .. 1
0 .. 2
0 .. 3
0 .. 3
0 .. 3
0 .. 3
0 .. 3
SJW
1.
Clock System
135