38.7.2.4 12-Bit Standard ID

Setting SID11EN (CxTDC[8]) 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 38-9. Data Byte Filter Configuration
DNCNT[4:0] Received Message Data Bits to Be Compared Byte [bits] EIDx Bits Used for Acceptance Filter
00000 No Comparison No Comparison
00001 Data Byte 0[7] EID[0]
00010 Data byte 0[7:6] EID[0:1]
00011 Data byte 0[7:5] EID[0:2]
00100 Data byte 0[7:4] EID[0:3]
00101 Data byte 0[7:3] EID[0:4]
00110 Data byte 0[7:2] EID[0:5]
00111 Data byte 0[7:1] EID[0:6]
01000 Data byte 0[7:0] EID[0:7]
01001 Data byte 0[7:0] and Data Byte 1[7] EID[0:8]
01010 Data byte 0[7:0] and Data Byte 1[7:6] EID[0:9]
01011 Data byte 0[7:0] and Data Byte 1[7:5] EID[0:10]
01100 Data byte 0[7:0] and Data Byte 1[7:4] EID[0:11]
01101 Data byte 0[7:0] and Data Byte 1[7:3] EID[0:12]
01110 Data byte 0[7:0] and Data Byte 1[7:2] EID[0:13]
01111 Data byte 0[7:0] and Data Byte 1[7:1] EID[0:14]
10000 Data byte 0[7:0] and Data Byte 1[7:0] EID[0:15]
10001 Byte 0[7:0] and Byte 1[7:0] and Byte 2[7] EID[0:16]
10010 to 11111 Byte 0[7:0] and Byte 1[7:0] and Byte 2[7:6] EID[0:17]

Figure 38-16 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 C1FLTOBJxH/L registers). The IDE bit of the received message must be ‘0’.

Figure 38-16. CAN Operation with DeviceNet™ Filtering