ST STM32F207 series User Manual

Controller area network (bxCAN) RM0033
804/1381 RM0033 Rev 9
identifiers. All bits of the incoming identifier must match the bits specified in the filter
registers.
Filter bank scale and mode configuration
The filter banks are configured by means of the corresponding CAN_FMR register. To
configure a filter bank it must be deactivated by clearing the FACT bit in the CAN_FAR
register. The filter scale is configured by means of the corresponding FSCx bit in the
CAN_FS1R register, refer to Figure 305. The identifier list or identifier mask mode for the
corresponding Mask/Identifier registers is configured by means of the FBMx bits in the
CAN_FMR register.
To filter a group of identifiers, configure the Mask/Identifier registers in mask mode.
To select single identifiers, configure the Mask/Identifier registers in identifier list mode.
Filters not used by the application should be left deactivated.
Each filter within a filter bank is numbered (called the Filter Number) from 0 to a maximum
dependent on the mode and the scale of each of the filter banks.
Concerning the filter configuration, refer to Figure 305.
Figure 305. Filter bank scale configuration - register organization
One 32-Bit Filter - Identifier Mask
Two 16-Bit Filters - Identifier Mask
CAN_FxR1[31:24]
CAN_FxR2[31:24]
CAN_FxR1[15:8]
CAN_FxR1[31:24]
CAN_FxR1[7:0]
CAN_FxR1[23:16]
x = filter bank number
FSCx = 1FSCx = 0
1
These bits are located in the CAN_FS1R register
Filter Bank Scale
ID
Mask
ID
Mask
STID[10:3] STID[2:0] EXID[12:5]
Mapping
STID[10:3]
ID
Mask
Mapping
RTR
Two 32-Bit Filters - Identifier List
ID
ID
STID[10:3] STID[2:0] EXID[12:5]
Mapping
Four 16-Bit Filters - Identifier List
ID
ID
STID[10:3]
ID
ID
Mapping
n
n+1
n+2
n+3
n+1
Filter Bank Mode
2
n
n
n+1
EXID[4:0] IDE EXID[17:13]
EXID[17:13]
STID[2:0] RTR IDE EXID[17:15]
FBMx = 0FBMx = 1
Filter
2
These bits are located in the CAN_FM1R register
n
Num.
FBMx = 0FBMx = 1
Config. Bits
1
STID[2:0] RTR IDE EXID[17:15]
0
RTREXID[4:0] IDE 0
CAN_FxR1[23:16] CAN_FxR1[15:8] CAN_FxR1[7:0]
CAN_FxR2[7:0]CAN_FxR2[15:8]CAN_FxR2[23:16]
CAN_FxR1[31:24]
CAN_FxR2[31:24]
CAN_FxR1[23:16] CAN_FxR1[15:8] CAN_FxR1[7:0]
CAN_FxR2[7:0]CAN_FxR2[15:8]CAN_FxR2[23:16]
CAN_FxR2[15:8]
CAN_FxR2[31:24]
CAN_FxR2[7:0]
CAN_FxR2[23:16]
CAN_FxR1[15:8]
CAN_FxR1[31:24]
CAN_FxR1[7:0]
CAN_FxR1[23:16]
CAN_FxR2[15:8]
CAN_FxR2[31:24]
CAN_FxR2[7:0]
CAN_FxR2[23:16]
ID=Identifier

ST STM32F207 series Specifications

General

Brand	ST
Model	STM32F207 series
Category	Microcontrollers
Language	English