GD32VF103 User Manual
434
Figure 20-5. 32-bit filter
FDATA[31:21]
FDATA[20:3]
FDATA[2:0]
SFID[10:0]
EFID[17:0]
FF
FT
0
16-bit: SFID [10:0], FT, FF and EFID[17:15] bits. As shown in
Figure 20-6. 16-bit filter
FDATA[31:21]
FDATA[20:16]
SFID[10:0]
FT FF EFID[17:15]
FDATA[15:5]
FDATA[4:0]
SFID[10:0]
FT
EFID[17:15]
FF
Mask mode
In mask mode the identifier registers are associated with mask registers specifying which bits
of the identifier are handled as “must match” (when the bit in mask register is ‘1’) or as “don’t
care” (when the bit in mask register is ‘0’). 32-bit mask mode example is shown in
Figure 20-7. 32-bit mask mode filter
FDATA1[31:21]
FDATA1[20:3]
FDATA1[2:0]
SFID[10:0]
EFID[17:0]
FF
FT
0
FDATA0[31:21]
FDATA0[20:3]
FDATA0[2:0]
ID
Mask
Figure 20-8. 16-bit mask mode filter
FDATA0[15:5]
FDATA0[4:0]
SFID[10:0]
FT
FF EFID[17:15]
FDATA1[15:5]
FDATA1[4:0]
SFID[10:0]
FT
FF EFID[17:15]
FDATA0[31:21]
FDATA0[20:16]
FDATA1[31:21]
FDATA1[20:16]
ID
Mask
List mode
The filter consists of frame identifiers. The filter can decide whether a frame will be discarded
or not. When one frame arrived, the filter will check which member can match the identifier of
the frame.
32-bit list mode example is shown in
Figure 20-9. 32-bit list mode filter
Figure 20-9. 32-bit list mode filter
FDATA1[31:21]
FDATA1[20:3]
FDATA1[2:0]
SFID[10:0]
EFID[17:0]
FF
FT
0
FDATA0[31:21]
FDATA0[20:3]
FDATA0[2:0]
ID
ID
Figure 20-10. 16-bit list mode filter
FDATA0[31:21]
FDATA0[20:16]
SFID[10:0]
FT
EFID[17:15]
FF
FDATA0[15:5]
FDATA0[4:0]
SFID[10:0]
FT
EFID[17:15]
FF
ID