CAN Notes (11) Bit Timing

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1. bit rate

The number of bits transmitted per second in the case of asynchronous transmission unit referred to by the bit rate

Bit baud rate can see ^a relationship: x bit rate = baud single modulation state corresponds to the number of bits
Clearly, two-phase modulation (modulation state corresponds to a single bit) of the bit rate equal to the baud rate
four-phase modulation (single modulation state corresponds to two binary bits) bit rate is twice the baud rate for the
eight-phase modulation (single modulation state corresponds to three bits) is three times the baud bit rate
and so on

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2. Bit Timing

A bit can be divided into 4 sections:

• Synchronization segment (SS)
• The propagation time (PTS)
• Phase Segment 1 (PBS1)
• Phase Segment 2 (PBS2)

The minimum time unit segments are made may be referred to as Time Quantum (Tq is hereinafter) constituting
a divided into four segments, each segment in turn consists of a plurality of Tq is, this is called bit timing

Consists of a number of Tq, and how many of each segment Tq like configuration, bit timing can be arbitrarily set
by setting the bit timing, the plurality of cells can be sampled at the same time, can be arbitrarily set the sampling point ²

The role of each segment and the number of Tq:

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3. constitute bit

A bit configuration:

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Reference:
"CAN Primer"

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Thank you!

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1. Baud Rate: The number of symbols of symbols transmitted per second, using a carrier frequency modulated state change per unit time is represented ↩︎

2. Sampling points: read bus level, and point value as a read level, a position at the end of PBS1 ↩︎