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14.3.4 CAN message buffer registers
(1)
Message identifier registers L00 to L31 and H00 to H31
(M_IDL00 to M_IDL31, M_IDH00 to M_IDH31)
The M_IDLm, M_IDHm registers specify the identifier and format of the corresponding message m
(m = 00 to 31).
These registers can be read/written 16-bit units.
Figure 14-24: Message Identifier Registers L00 to L31 and H00 to H31
15
14
13
M_ID
IDE
0
0
ID28 ID27 ID26 ID25 ID24 ID23 ID22 ID21 ID20 ID19 ID18 ID17 ID16
Hm
15
14
13
M_IDL
ID15 ID14 ID13 ID12 ID11 ID10 ID9 ID8 ID7 ID6 ID5 ID4 ID3 ID2 ID1 ID0
m
Bit Position
Bit Name
15
IDE
(M_IDHm)
12 to 0
ID28 to
(M_IDHm)
ID16
15 to 0
ID15 to ID0
(M_IDLm)
Notes: 1. The register address is calculated according to the following formula:
effective address = PP_BASE + address offset
2. In standard format mode (IDE = 0) these bits (ID17 to ID0) are only used for receive mes-
sage buffers linked to a mask.
- Bits ID17 to ID10 storing the first data byte (D0) is stored, where ID17 is the MSB.
- Bits ID9 to ID2 storing the second data byte (D1), where ID9 is the MSB
- Bits ID1, ID0 contain the two most significant bits 7 and 6 of the third byte (D2)
3. When received message in standard format mode (IDE = 0) has less than 18 data bits, the
values of the not received bits are undefined.
Remark:
m = 00 to 31
472
Chapter 14 FCAN Interface Function
(M_IDL00 to M_IDL31, M_IDH00 to M_IDH31)
12
11
10
9
8
12
11
10
9
8
Specifies the format of message identifier.
0: Standard format mode (11-bit)
1: Extended format mode (29-bit)
When IDE = 0 (standard format):
ID28 to ID18 specify the 11-bit identifier, where ID28 is the most significant bit.
ID17, ID16 contain received data bits.
When IDE = 1 (extended format):
ID28 to ID16 specify the 13 most significant bits of the 29-bit identifier, where ID28
is the most significant bit.
When IDE = 0 (standard format):
ID15 to ID0 contain received data bits.
When IDE = 1 (extended format):
ID15 to ID0 specify the 16 least significant bits of the 29-bit identifier.
Preliminary User's Manual U15839EE1V0UM00
7
6
5
4
3
7
6
5
4
3
Function
Note 2, 3
Note 2, 3
Address
2
1
0
Note 1
Offset
812H
+(m × 20H
)
2
1
0
810H
+(m × 20H
)
Initial
value
undef.
undef.
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