BAT32G1x9 user manual | Chapter 22 CAN control
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Rev.1.02
Reference: The CAN standard ISO 11898 specification defines the segments that make up the data bit
time, as shown Figure 22-19
Figure 22-19. Reference: Data bit time configuration as defined by the CAN specification
Data Bit Time (DBT
).
Synchronize
segments
Propagate
segments
Phase segment 1
Phase segment 2
SJW
Sample Point (SPT
).
Segment name
Segment length
description
Synchronize segments
1
This segment begins at the edge where the level changes
from recessive to dominant when hard synchronization is
established
Propagate segments
Programmable from 1
to
8
or more
This segment absorbs the latency of the output buffer,
CAN bus, and input buffer.
Set the length of this segment so that ACK is returned
before phase 1 starts
Propagation period
(output buffer delay) +2x
(CAN bus delay) + (input buffer delay).
Phase segment 1
Programmable 1
to
8
This segment compensates for errors in data bit times.
The longer this segment, the wider the allowable range,
but the slower the communication speed
Phase segment 2
Phase band 1
or
IPT,
whichever is
the
largest
SJW
Programmable from
1TQ
to segment 1
or
4TQ,
whichever
is the smallest
This width sets the upper limit of the phase segment that
is expanded or contracted during resynchronization
Remarks: IPT: Information processing time
TQ: Time share