M16C6NK Datasheet, PDF (258/404 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

Under development
This document is under development and its contents are subject to change.
M16C/6N Group (M16C/6NK, M16C/6NM)
19. CAN Module
19.10 Acceptance Filter Support Unit (ASU)
The acceptance filter support unit has a function to judge valid/invalid of a received ID through table search.
The IDs to receive are registered in the data table; a received ID is stored in the CiAFS register ( i = 0, 1),
and table search is performed with a decoded received ID. The acceptance filter support unit can be used
for the IDs of the standard frame only.
The acceptance filter support unit is valid in the following cases.
• When the ID to receive cannot be masked by the acceptance filter.
(Example) IDs to receive: 078h, 087h, 111h
• When there are too many IDs to receive; it would take too much time to filter them by software.
Figure 19.18 shows the write and read of the CiAFS register in word access.
b15
When write
b8 b7
SID10 SID9 SID8 SID7 SID6
3/8 Decoder
b0
SID5 SID4 SID3 SID2 SID1 SID0
Addresses
CAN0 CAN1
242h 244h
b15
When read
b8 b7
b0
SID10 SID9 SID8 SID7 SID6 SID5 SID4 SID3 242h 244h
Figure 19.18 Write/read of CiAFS Register in Word Access
Rev.2.00 Nov 28, 2005 page 240 of 378
REJ09B0124-0200