Microchip Technology dsPIC33 series - Figure 8-2: Filter Match

 2018 Microchip Technology Inc. DS70005340A-page 83
CAN FD Protocol Module
Figure 8-2: Filter Match
Start Matching
C1MASKxH.MIDE
Set?
Check IDE:
C1FLTOBJxH.EXIDE == RXMAB.IDE?
Yes
No Match
Match
No
RXMAB.IDE == 0?
Base Format:
C1FLTOBJx.SID == RXMAB.SID,
Don’t Care if C1MASKx.MSID[i] = 0
Yes
Extended Format:
C1FLTOBJx.SID == RXMAB.SID,
Don’t Care if C1MASKx.MSID[i] = 0
No
No
Yes
NO Match No MatchNo No
C1FLTOBJx.EID == RXMAB.EID,
Don’t Care if C1MASKx.MEID[i] = 0
Yes
No MatchNo
SID11:
C1TDCH.SID11EN and
C1MASKx.MSID11
Check SID11:
C1FLTOBJxH.SID11 == RXMAB.SID11?
Yes
Yes
Yes
Data Bytes:
C1CONL.DNCNTx > 0 ?
No
Yes No MatchNo
No
Calculate Number of Bits to Compare:
N = DNCNTx
Calculate Index:
M = 18-N
Assemble Receive Data Bytes:
RXDB = {RXMAB.DB0, RXMAB.DB1, RXMAB.DB2[7:6]}
Compare:
C1FLTOBJm.EID[0:N] == RXDB[17 : M] ?
Don’t Care if C1MASKm.MEID[i] = 0
Yes
No MatchNo
Match
Yes