Datasheet

MSCAN Controller
Technical Data MC68HC912DT128A — Rev 4.0
344 MSCAN Controller MOTOROLA
• Time segment 1: This segment includes the PROP_SEG and the
PHASE_SEG1 of the CAN standard. It can be programmed by
setting the parameter TSEG1 to consist of 4 to 16 time quanta.
• Time segment 2: This segment represents the PHASE_SEG2 of
the CAN standard. It can be programmed by setting the TSEG2
parameter to be 2 to 8 time quanta long.
The synchronization jump width can be programmed in a range of 1 to 4
time quanta by setting the SJW parameter.
Above parameters can be set by programming the bus timing registers
(CBTR0–1, see msCAN12 Bus Timing Register 0 (CBTR0) and
msCAN12 Bus Timing Register 1 (CBTR1)).
It is the user’s responsibility to make sure that his bit time settings are in
compliance with the CAN standard. Figure 18-9 gives an overview on
the CAN conforming segment settings and the related parameter values.
Figure 18-8. Segments within the Bit Time
SYNC
_SEG
Time segment 1 Time Seg. 2
1 4 ... 16 2 ... 8
8... 25 Time Quanta
= 1 Bit Time
NRZ Signal
Sample point
(single or triple sampling)
(PROP_SEG + PHASE_SEG1) (PHASE_SEG2)
Transmit point
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
nc...