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10 bit timing requirements, Bosch, Bit timing – Rainbow Electronics CAN интерфейс User Manual

Page 67

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BOSCH

ROBERT BOSCH GmbH, Postfach 300240, D-7000 Stuttgart 30

Sep. 1991

Part B - page 65

10 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.

SYNC_SEG

PROP_SEG

PHASE_SEG1

PHASE_SEG2

Sample Point

NOMINAL BIT TIME

Bit Timing