Controller area network (bxCAN)
RM0090
1108/1731
DocID018909 Rev 11
Filter bank i register x (CAN_FiRx) (i=0..27, x=1, 2)
Address offsets: 0x240..0x31C
Reset value: 0xXXXX XXXX
There are 28 filter banks, i=0 .. 27. Each filter bank i is composed of two 32-bit registers,
CAN_FiR[2:1].
This register can only be modified when the FACTx bit of the CAN_FAxR register is cleared
or when the FINIT bit of the CAN_FMR register is set.
In all configurations:
Note:
Depending on the scale and mode configuration of the filter the function of each register can
differ. For the filter mapping, functions description and mask registers association, refer to
Section 32.7.4: Identifier filtering on page 1078
A Mask/Identifier register in
mask mode
has the same bit mapping as in
identifier list
mode.
For the register mapping/addresses of the filter banks please refer to the
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FB31
FB30
FB29
FB28
FB27
FB26
FB25
FB24
FB23
FB22
FB21
FB20
FB19
FB18
FB17
FB16
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FB15
FB14
FB13
FB12
FB11
FB10
FB9
FB8
FB7
FB6
FB5
FB4
FB3
FB2
FB1
FB0
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 31:0
FB[31:0]
: Filter bits
Identifier
Each bit of the register specifies the level of the corresponding bit of the expected identifier.
0: Dominant bit is expected
1: Recessive bit is expected
Mask
Each bit of the register specifies whether the bit of the associated identifier register must
match with the corresponding bit of the expected identifier or not.
0: Don’t care, the bit is not used for the comparison
1: Must match, the bit of the incoming identifier must have the same level has specified in
the corresponding identifier register of the filter.