DS80C390_00 Datasheet, PDF (127/155 Pages) Dallas Semiconductor – High-Speed Microcontroller User’s Guide Supplement

DS80C390 High-Speed Microcontroller User’s Guide Supplement
CAN Message Center 15 Mask Register 0 (CnM15M0)
MOVX
Address¹
7
6
5
4
3
2
1
0
xxxx0Ch MASK28 MASK27 MASK26 MASK25 MASK24 MASK23 MASK22 MASK21
CAN Message Center 15 Mask Register 1 (CnM15M1)
MOVX
Address¹
7
6
5
4
3
2
1
0
xxxx0Dh MASK20 MASK19 MASK18 MASK17 MASK16 MASK15 MASK14 MASK13
CAN 0 Message Center 15 Mask Register 2 (CnM15M2)
MOVX
Address¹
7
6
5
4
3
2
xxxx0Eh MASK12 MASK11 MASK10 MASK9 MASK8 MASK7
1
MASK6
0
MASK5
CAN 0 Message Center 15 Mask Register 3 (CnM15M3)
MOVX
Address¹
7
6
5
4
3
2
1
0
xxxx0Fh MASK4 MASK3 MASK2 MASK1 MASK0
0
0
0
MASK28-MASK0
CAN Message Center 15 Mask Registers 0-3. These registers function as the
mask when performing the Extended Global Identification test (EX/ ST =1) for
Message Center 15 only. These registers can only be modified during a software
initialization (SWINT=1).
When EX/ ST =1, the 29 bits of the message ID will be compared against the 29
bits of the CAN Message Center 15 Arbitration Registers, using the 29 bits of the
CAN Message Center 15 Mask Registers as a mask. When EX/ ST =0, the 11 bits
of the message ID will be compared against the most significant 11 bits of the
CAN Message Center 15 Arbitration Registers, using the most significant 11 bits
of the CAN Message Center 15 Mask Registers as a mask. Any bit in the CAN
Message Center 15 Mask Registers set to 0 will ignore the state of the
corresponding bit in the incoming message ID field when performing the test.
Any bit in the CAN Message Center 15 Mask Registers set to 1 will force the
state of the corresponding bit in the incoming message ID field and CAN message
center arbitration Registers 0-3 to match before considering the incoming message
a match.
The three least significant bits in the CnM15M3 register are not used, and will not
perform any comparison of these bit locations. A read of these bits will always
return 0, and writes to these bits will be ignored.
Programming all Mask registers to 00h effectively disables the Message Center 15
ID test, accepting all messages. As such the Message Center 15 mask registers act
as a don’t care following a system Reset.
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