Datasheet

Table Of Contents
PIC18F2480/2580/4480/4580
DS39637D-page 308 © 2009 Microchip Technology Inc.
24.2.3.2 Message Acceptance Filters
and Masks
This section describes the message acceptance filters
and masks for the CAN receive buffers.
REGISTER 24-37: RXFnSIDH: RECEIVE ACCEPTANCE FILTER n STANDARD IDENTIFIER FILTER
REGISTERS, HIGH BYTE [0 n 15]
(1)
R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
SID10 SID9 SID8 SID7 SID6 SID5 SID4 SID3
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 SID<10:3>: Standard Identifier Filter bits (if EXIDEN = 0)
Extended Identifier Filter bits, EID<28:21> (if EXIDEN = 1).
Note 1: Registers, RXF6SIDH:RXF15SIDH, are available in Mode 1 and 2 only.
REGISTER 24-38: RXFnSIDL: RECEIVE ACCEPTANCE FILTER n STANDARD IDENTIFIER FILTER
REGISTERS, LOW BYTE [0 n 15]
(1)
R/W-x R/W-x R/W-x U-0 R/W-x U-0 R/W-x R/W-x
SID2 SID1 SID0
EXIDEN
(2)
—EID17EID16
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 SID<2:0>: Standard Identifier Filter bits (if EXIDEN = 0)
Extended Identifier Filter bits, EID<20:18> (if EXIDEN = 1).
bit 4 Unimplemented: Read as ‘0
bit 3 EXIDEN: Extended Identifier Filter Enable bit
(2)
1 = Filter will only accept extended ID messages
0 = Filter will only accept standard ID messages
bit 2 Unimplemented: Read as ‘0
bit 1-0 EID<17:16>: Extended Identifier Filter bits
Note 1: Registers, RXF6SIDL:RXF15SIDL, are available in Mode 1 and 2 only.
2: In Mode 0, this bit must be set/cleared as required, irrespective of corresponding mask register value.