
49.4.3 Message buffer structure
The message buffer structure used by the FlexCAN module is represented in the
following figure. Both extended (29-bit identifier) and standard (11-bit identifier) frames
used in the CAN specification (Version 2.0 Part B) are represented. Each individual MB
is formed by 16, 24, 40, or 72 bytes, depending on the quantity of data bytes allocated for
the message payload: 8, 16, 32, or 64 data bytes, respectively.
The memory area from 0x80 to 0x27F is used by the mailboxes. When CAN FD is
enabled, the exact address for each MB depends on the size of its payload. See
for more detailed information.
Table 49-9. Message buffer structure — example with 64-byte payload
31
30
29
28
27
24 23
22
21
20
19 18 17 16 15
8 7
0
0x0
EDL BRS
ESI
CODE
SRR
IDE
RTR
DLC
TIME STAMP
0x4
PRIO
ID (standard/extended)
ID (extended)
0x8
Data byte 0
Data byte 1
Data byte 2
Data byte 3
0xC
Data byte 4
Data byte 5
Data byte 6
Data byte 7
0x10
Data byte 8
Data byte 9
Data byte 10
Data byte 11
0x14
Data byte 12
Data byte 13
Data byte 14
Data byte 15
0x18
Data byte 16
Data byte 17
Data byte 18
Data byte 19
0x1C
Data byte 20
Data byte 21
Data byte 22
Data byte 23
0x20
Data byte 24
Data byte 25
Data byte 26
Data byte 27
0x24
Data byte 28
Data byte 29
Data byte 30
Data byte 31
0x28
Data byte 32
Data byte 33
Data byte 34
Data byte 35
0x2C
Data byte 36
Data byte 37
Data byte 38
Data byte 39
0x30
Data byte 40
Data byte 41
Data byte 42
Data byte 43
0x34
Data byte 44
Data byte 45
Data byte 46
Data byte 47
0x38
Data byte 48
Data byte 49
Data byte 50
Data byte 51
0x3C
Data byte 52
Data byte 53
Data byte 54
Data byte 55
0x40
Data byte 56
Data byte 57
Data byte 58
Data byte 59
0x44
Data byte 60
Data byte 61
Data byte 62
Data byte 63
= Unimplemented or reserved
EDL — Extended Data Length
This bit distinguishes between CAN format and CAN FD format frames. The EDL bit
must not be set for message buffers configured to RANSWER with code field 0b1010
(see table below).
BRS — Bit Rate Switch
This bit defines whether the bit rate is switched inside a CAN FD format frame.
Chapter 49 FlexCAN
MWCT101xS Series Reference Manual, Rev. 3, 07/2019
NXP Semiconductors
1645
Summary of Contents for MWCT101 S Series
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Page 70: ...Aliased bit band regions MWCT101xS Series Reference Manual Rev 3 07 2019 70 NXP Semiconductors...
Page 78: ...Pinout diagrams MWCT101xS Series Reference Manual Rev 3 07 2019 78 NXP Semiconductors...
Page 96: ...WCT101xS safety concept MWCT101xS Series Reference Manual Rev 3 07 2019 96 NXP Semiconductors...
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Page 472: ...Application Information MWCT101xS Series Reference Manual Rev 3 07 2019 472 NXP Semiconductors...
Page 528: ...Module clocks MWCT101xS Series Reference Manual Rev 3 07 2019 528 NXP Semiconductors...
Page 634: ...SRAM configuration MWCT101xS Series Reference Manual Rev 3 07 2019 634 NXP Semiconductors...
Page 818: ...Functional description MWCT101xS Series Reference Manual Rev 3 07 2019 818 NXP Semiconductors...
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Page 992: ...ADC calibration scheme MWCT101xS Series Reference Manual Rev 3 07 2019 992 NXP Semiconductors...
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Page 1726: ...Debug and security MWCT101xS Series Reference Manual Rev 3 07 2019 1726 NXP Semiconductors...
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