Maxim Integrated MAXQ7666 - Manual (Page 146)

MAXQ7665/MAXQ7666 User’s Guide
4-16
CAN 0 Message Center 15 Mask Register 3 (C0M15M3)
CAN Message Center 15 Mask Registers 0 to 3 (C0M15M0 to C0M15M3). These registers function as the mask for the standard
(EX/
ST = 0) or extended (EX/ST = 1) global identification test (EX/ST = 1) when message ID masking has been enabled (MEME = 1)
for message center 15. These registers can only be modified during a software initialization (SWINT = 1).
When EX/ ST = 1, the 29 bits of the message ID are 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 are com-
pared 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 0 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 forces the state of the corresponding bit in the incoming message ID field and CAN message center arbitration reg-
isters 0–3 to match before considering the incoming message a match.
The three least significant bits in the C0M15M3 register are not used and will not perform any comparison of these bit locations. A read
of these bits always returns 0, and writes to these bits are ignored.
Programming all mask registers to 00h effectively disables the message center 15 ID test, accepting all messages. As such the mes-
sage center 15 mask registers act as a don’t care following a system reset.
Bit # 7 6 5 4 3 2 1 0
Name MASK4 MASK3 MASK2 MASK1 MASK0 — — —
Reset 0 0 0 0 0 0 0 0
Access rw rw rw rw rw rw rw rw
Dual Port
Address
07h(H)
r = read, w = write (allowed only when SWINT = 1 via C0DP/C0DB)
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