FlexCAN
30-27
Freescale Semiconductor
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
Figure 30-15. Segments within the Bit Time
gives an overview of the CAN compliant segment settings and the related parameter values.
NOTE
It is the user’s responsibility to ensure the bit time settings are in compliance
with the CAN standard. For bit time calculations, use an IPT (Information
Processing Time) of 2, which is the value implemented in the FlexCAN
module
Table 30-14. Time Segment Syntax
Syntax
Description
SYNC_SEG
System expects transitions to occur on the 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 samples the bus at this point. If the three samples per bit
option is selected, then this point marks the position of the third
sample.
Table 30-15. CAN Standard Compliant Bit Time Segment Settings
Time Segment 1
Time Segment 2
Re-synchronization
Jump Width
5 .. 10
2
1 .. 2
4 .. 11
3
1 .. 3
5 .. 12
4
1 .. 4
6 .. 13
5
1 .. 4
7 .. 14
6
1 .. 4
SYNC_SEG
Time Segment 1
Time Segment 2
1
4 ... 16
2 ... 8
8 ... 25 Time Quanta
= 1 Bit Time
NRZ Signal
Sample Point
(single or triple sampling)
(PR PSEG1 + 2)
(PSEG2 + 1)
Transmit Point
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
