7
Appendix
7.1
Acceptance Filtering
Four 8-bits Acceptance Code registers (AC0, AC1, AC2 and AC3) and
Acceptance Mask registers (AM0, AM1, AM2 and AM3) are available for a
various filtering of messages. These registers can be used for controlling a
4-byte filter, which can check the specific bits of a CAN message and decide
if this message will be passed to the CAN card or not. The message filter
general concept is shown in Figure A.1. The Acceptance Code Register is
mainly used for deciding what kind of message ID the CAN card will accept.
The Acceptance Mask Register is mainly used for deciding which bit of
message ID will need to check by using the Acceptance Code Register. If
the bit of the Acceptance Mask is set to 0, it means that the bit in the same
position of message ID needs to be checked.
ACR0
ACR1
ACR2
ACR3
AMR0
AMR1
AMR2
AMR3
Filter
11 bit Identifier
Data 1 Data 2
11 bit Identifier
18 bit Identifier
OR
Bits used for acceptance filtering
Bits used for acceptance filtering
Standard Frame
Extended Frame
RTR bit
RTR bit
Receive
FIFO
Acceptance Filtering
CAN Message
Figure A.1 Acceptance Filter
PISO-CAN/PEX-CAN/PCM-CAN Series User’s Manual (v2.6 Dec/2013) -------
81
ГК
Атлант
Инжиниринг
–
официальный
представитель
в
РФ
и
СНГ
+7(495)109-02-08 [email protected] www.bbrc.ru
