• Reject received frame
• Set High Priority Message interrupt flag IR.HPM
• Set High Priority Message interrupt flag IR.HPM and store received frame in FIFO 0
or FIFO 1
Acceptance filtering is started after the complete identifier has been received. After
acceptance filtering has completed, and if a matching Rx Buffer or Rx FIFO has been
found, the Message Handler starts writing the received message data in portions of 32 bit
to the matching Rx Buffer or Rx FIFO. If the CAN protocol controller has detected an
error condition (e.g. CRC error), this message is discarded with the following impact on
the affected Rx Buffer or Rx FIFO:
Rx Buffer
New Data flag of matching Rx Buffer is not set, but Rx Buffer (partly) overwritten with
received data. For error type see PSR[LEC] respectively PSR[FLEC].
Rx FIFO
Put index of matching Rx FIFO is not updated, but related Rx FIFO element (partly)
overwritten with received data. For error type see PSR[LEC] respectively PSR[FLEC]. In
case the matching Rx FIFO is operated in overwrite mode, the boundary conditions
described in "Rx FIFO Overwrite Mode" section have to be considered.
Note
When an accepted message is written to one of the two Rx
FIFOs, or into an Rx Buffer, the unmodified received identifier
is stored independent of the filter(s) used. The result of the
acceptance filter process is strongly depending on the sequence
of configured filter elements.
3.5.4.1.1 Range Filter
The filter matches for all received frames with Message IDs in the range defined by
SF1ID/SF2ID resp. EF1ID/EF2ID.
There are two possibilities when range filtering is used together with extended frames:
• EFT = "00": The Message ID of received frames is ANDed with the Extended ID
AND Mask (XIDAM) before the range filter is applied
• EFT = "11": The Extended ID AND Mask (XIDAM) is not used for range filtering
Chapter 3 Modular CAN (M_CAN)
MPC5777C Reference Manual Addendum, Rev. 1, 12/2015
Freescale Semiconductor, Inc. 99
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