Rainbow Electronics CAN интерфейс - Manual (Page 29)

BOSCH
ROBERT BOSCH GmbH, Postfach 50, D-7000 Stuttgart 1
Sep. 1991
Part A - page 27
8 BIT TIMING REQUIREMENTS
NOMINAL BIT RATE
The Nominal Bit Rate is the number of bits per second transmitted in the absence of
resynchronization by an ideal transmitter.
NOMINAL BIT TIME
NOMINAL BIT TIME = 1 / NOMINAL BIT RATE
The Nominal Bit Time can be thought of as being divided into separate non-overlapping
time segments. These segments
- SYNCHRONIZATION SEGMENT (SYNC_SEG)
- PROPAGATION TIME SEGMENT (PROP_SEG)
- PHASE BUFFER SEGMENT1 (PHASE_SEG1)
- PHASE BUFFER SEGMENT2 (PHASE_SEG2)
form the bit time as shown in figure 1.
Fig. 1 Partition of the Bit Time
SYNC SEG
This part of the bit time is used to synchronize the various nodes on the bus. An edge
is expected to lie within this segment.
PROP SEG
This part of the bit time is used to compensate for the physical delay times within the
network.
SYNC_SEG PROP_SEG PHASE_SEG1 PHASE_SEG2
Sample Point
NOMINAL BIT TIME
Fault Confinement