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Rev.1.10 Jul 01, 2005 page 218 of 318
REJ09B0124-0110
M16C/6N Group (M16C/6NK, M16C/6NM) 18. CAN Module
Under development
This document is under development and its contents are subject to change.
Figure 18.16 Correspondence of Mask Registers to Slots
Figure 18.17 Acceptance Function
When using the acceptance function, note the following points.
(1) When one ID is defined in two slots, the one with a smaller number alone is valid.
(2) When it is configured that slots 14 and 15 receive all IDs with Basic CAN mode, slots 14 and 15 receive
all IDs which are not stored into slots 0 to 13.
18.9 Acceptance Filtering Function and Masking Function
These functions serve the users to select and receive a facultative message. The CiGMR register (i = 0, 1),
the CiLMAR register, and the CiLMBR register can perform masking to the standard ID and the extended ID
of 29 bits. The CiGMR register corresponds to slots 0 to 13, the CiLMAR register corresponds to slot 14,
and the CiLMBR register corresponds to slot 15. The masking function becomes valid to 11 bits or 29 bits
of a received ID according to the value in the corresponding slot of the CiIDR register upon acceptance
filtering operation. When the masking function is employed, it is possible to receive a certain range of IDs.
Figure 18.16 shows correspondence of the mask registers and slots, Figure 18.17 shows the acceptance
function.
Slot #0
Slot #1
Slot #2
Slot #3
Slot #4
Slot #5
Slot #6
Slot #7
Slot #8
Slot #9
Slot #10
Slot #11
Slot #12
Slot #14
Slot #15
CiGMR register
Slot #13
CiLMAR register
CiLMBR register
i = 0, 1
ID of the
received message
ID stored in
the slot
The value of the
mask register
Acceptance Signal
Mask Bit Values
Acceptance judge signal
0: The CAN module ignores the
current incoming message.
(Not stored in any slot)
1: The CAN module stores the
current incoming message in
a slot of which ID matches.
0: ID (to which the received message
corresponds) match is handled as
"Don’t care".
1: ID (to which the received message
corresponds) match is checked.