3.5.4.1.2 Filter for Specific IDs
A filter element can be configured to filter for one or two specific Message IDs. To filter
for one specific Message ID, the filter element has to be configured with SF1ID = SF2ID
resp. EF1ID = EF2ID.
3.5.4.1.3 Classic Bit Mask Filter
Classic bit mask filtering is intended to filter groups of Message IDs by masking single
bits of a received Message ID. With classic bit mask filtering SF1ID/EF1ID is used as
Message ID filter, while SF2ID/EF2ID is used as filter mask.
A zero bit at the filter mask will mask out the corresponding bit position of the
configured ID filter, e.g. the value of the received Message ID at that bit position is not
relevant for acceptance filtering. Only those bits of the received Message ID where the
corresponding mask bits are one are relevant for acceptance filtering.
In case all mask bits are one, a match occurs only when the received Message ID and the
Message ID filter are identical. If all mask bits are zero, all Message IDs match.
3.5.4.1.4 Standard Message ID Filtering
The following figure shows the flow for standard Message ID (11-bit Identifier) filtering.
The Standard Message ID Filter element is described in Standard Message ID Filter
Element.
Controlled by the Global Filter Configuration GFC and the Standard ID Filter
Configuration SIDFC Message ID, Remote Transmission Request bit (RTR), and the
Identifier Extension bit (IDE) of received frames are compared against the list of
configured filter elements.
Functional Description
MPC5777C Reference Manual Addendum, Rev. 1, 12/2015
100 Freescale Semiconductor, Inc.
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