Users Guide: Network Microcontroller Supplement User Manual

High-Speed Microcontroller User’s
Guide: Network Microcontroller
Supplement
139
CAN 0 Media ID Mask Register 0 (C0MID0)
MOVX Address
1
7 6543210
xxxx00h
CAN 0 Media ID Mask Register 1 (C0MID1)
MOVX Address
1
7 6543210
xxxx02h
CAN 0 Media Arbitration Register 0 (C0MA0)
CAN 0 media ID mask registers 1-0. These registers function as the mask when performing the media
identification test. This register can be only modified during a software initialization (SWINT = 1). If
MDME = 0, the media identification test cannot be performed, and the contents of these registers are
ignored. If MDME = 1, the CAN module performs an additional qualifying test on data bytes 0 and 1 of
the incoming message, regardless of the state of the EX/ST bit. Data byte 1 is compared against the
CAN media byte arbitration register 1 utilizing C0MID1 as a mask, and data byte 0 is compared against
CAN media byte arbitration register 0 utilizing C0MID0 as a mask. Any bit in the C0MID1 or C0MID0
masks programmed to 0 ignores the state of the corresponding data byte bit when performing the test.
Any bit in the C0MID1, C0MID0 masks programmed to 1 forces the state of the corresponding data byte
bit and CAN media byte arbitration registers 1 and 0 to match before considering the incoming mes-
sage a match. Programming either media ID mask r
egister to 00h effectively disables the media ID test
for that byte. As such, the C0MID1, C0MID0 masks act as a “don’t care” following a system reset.
CAN 0 media arbitration register 1-0. These registers function as the arbitration field when performing
the media identification test. If MDME = 0, the media identification test cannot be performed and the
contents of these registers are ignored. If MDME = 1, the CAN module performs an additional qualify-
ing test on data bytes 0 and 1 of the incoming message, as mentioned in the description of the CAN
media ID mask registers. This register can be modified only during a software initialization (SWINT = 1).
MOVX Address
1
76543210
xxxx01h
CAN 0 Media Arbitration Register 1 (C0MA1)
MOVX Address
1
76543210
xxxx03h
Maxim Integrated