14.9.2.4 12-Bit Standard ID

Setting SID11EN (CxTDC[24]) allows the use of RRS as bit 12 of the SIDx (LSB). 12-Bit SID mode is only available for CAN FD base frames. The filter is extended by SID11 and MSID11. Data bytes can also be filtered in this mode.

Table 14-11. Data Byte Filter Configuration
DNCNT[4:0]Received Message Data Bits to be Compared Byte [bits]EIDx Bits Used for Acceptance Filter
00000No ComparisonNo Comparison
00001Data Byte 0[7]EID[0]
00010Data Byte 0[7:6]EID[0:1]
00011Data Byte 0[7:5]EID[0:2]
00100Data Byte 0[7:4]EID[0:3]
00101Data Byte 0[7:3]EID[0:4]
00110Data Byte 0[7:2]EID[0:5]
00111Data Byte 0[7:1]EID[0:6]
01000Data Byte 0[7:0]EID[0:7]
01001Data Byte 0[7:0] and Data Byte 1[7]EID[0:8]
01010Data Byte 0[7:0] and Data Byte 1[7:6]EID[0:9]
01011Data Byte 0[7:0] and Data Byte 1[7:5]EID[0:10]
01100Data Byte 0[7:0] and Data Byte 1[7:4]EID[0:11]
01101Data Byte 0[7:0] and Data Byte 1[7:3]EID[0:12]
01110Data Byte 0[7:0] and Data Byte 1[7:2]EID[0:13]
01111Data Byte 0[7:0] and Data Byte 1[7:1]EID[0:14]
10000Data Byte 0[7:0] and Data Byte 1[7:0]EID[0:15]
10001Byte 0[7:0] and Byte 1[7:0] and Byte 2[7]EID[0:16]
10010 to 11111Byte 0[7:0] and Byte 1[7:0] and Byte 2[7:6]EID[0:17]

Figure 14-18 illustrates how the first 18 data bits of the received message data payload are compared with the corresponding EIDx bits of the message acceptance filter (EID[17:0] bits in the CxFLTOBJx registers). The IDE bit of the received message must be ‘0’.

Figure 14-18. CAN Operation with DeviceNet™ Filtering