NXP Semiconductors MWCT101 S Series, Reference Manual

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Table 49-27. Bosch CAN 2.0B 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
8 .. 15 7 1 .. 4
9 .. 16 8 1 .. 4
Note
The user must ensure the bit time settings are in compliance
with the CAN Protocol standard (ISO 11898-1).
Whenever CAN bit is used as a measure of time duration (for example, estimating the
occurrence of a CAN bit event in a message), the number of peripheral clocks in one
CAN bit (NumClkBit) can be calculated as:
NumClkBit = x (P 1) x (P PSEG1 + PSEG2 + 4)
fCANCLK
fSYS
where:
• NumClkBit is the number of peripheral clocks in one CAN bit.
• f
CANCLK
is the Protocol Engine (PE) Clock (see Figure 49-6 ), in Hz.
• f
SYS
is the frequency of operation of the system (CHI) clock, in Hz.
• PSEG1 is the value in CTRL1[PSEG1] field.
• PSEG2 is the value in CTRL1[PSEG2] field.
• PROPSEG is the value in CTRL1[PROPSEG] field.
• PRESDIV is the value in CTRL1[PRESDIV] field.
The formula above is also applicable to the alternative CAN bit timing variables
described in the CAN Bit Timing register (CBT) and also to the CAN FD Bit Timing
register (FDCBT).
For example, 180 CAN bits = (180 x NumClkBit) peripheral clock periods.
49.5.9.8 Arbitration and matching timing
During normal reception and transmission, the matching, arbitration, move-in, and move-
out processes are executed during certain time windows inside the CAN frame, as shown
in the following figures.
Functional description
MWCT101xS Series Reference Manual, Rev. 3, 07/2019
1696 NXP Semiconductors