Figure 343. Example Of Filter Numbering - STMicroelectronics STM32F405 Reference Manual

RM0090
Filter
Bank
0
1
3
5
6
9
13
Filter priority rules
Depending on the filter combination it may occur that an identifier passes successfully
through several filters. In this case the filter match value stored in the receive mailbox is
chosen according to the following priority rules:
•
A 32-bit filter takes priority over a 16-bit filter.
•
For filters of equal scale, priority is given to the
Mask mode
• For filters of equal scale and mode, priority is given by the filter number (the lower the
number, the higher the priority).

Figure 343. Example of filter numbering

Filter
FIFO0
Num.
0
ID List (32-bit)
1
2
ID Mask (32-bit)
3
4
ID List (16-bit)
5
6
Deactivated
7
ID List (32-bit)
8
9
ID Mask (16-bit)
10
11
ID List (32-bit)
12
ID Mask (32-bit) 13
DocID018909 Rev 11
Controller area network (bxCAN)
Filter
FIFO1
Bank
2
ID Mask (16-bit)
4
ID List (32-bit)
Deactivated
7
ID Mask (16-bit)
8
ID Mask (16-bit)
Deactivated
10
ID List (16-bit)
11
ID List (32-bit)
12
ID Mask (32-bit)
List mode over the
Identifier
Filter
Num.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
ID=Identifier
Identifier
1081/1731
1112