NXP Semiconductors MWCT101 S Series, Reference Manual

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• A match with the maximum range of payload, that is, any message with payload
value smaller than or equal to the content of PL1 register is accepted. The payload
mask is not used.
• A match with the minimum range of payload, that is, any message with payload
value greater than or equal to the content of PL1 register is accepted. The payload
mask is not used.
• A match inside a range of payloads, that is, any message with a payload value that is
greater than or equal to the content of PL1 register and smaller than or equal to the
content of PL2 register is accepted. The payload mask is not used.
See CTRL1_PN[PLFS] in Pretended Networking Control 1 register (CTRL1_PN) .
The above criteria for payload filtering must be coherent with FLT_DLC upper and lower
limit values in FLT_DLC register. The payload of an Rx incoming message is filtered in
accordance with the selected criteria only if the DLC value of the Rx incoming message
is inside a DLC range:
• Greater than or equal to the FLT_DLC_LO (lower limit)
• Lower than or equal to the FLT_DLC_HI (upper limit)
Conversely, a DLC value out of the specified range results in a mismatch. By making
FLT_DLC_LO = FLT_DLC_HI, only payloads of the specified quantity of bytes will be
filtered. DLC is not maskable.
When the inside range of payloads option is selected (CTRL1_PN[PLFS] = 11), both
PL1 and PL2 are considered with the 8-byte data length. All the data bytes excluded by
the DLC of the received message are considered with value zero.
Payload mask is only used in the exact match option (CTRL1_PN[PLFS] = 00) to select
which bits or bytes in the 8-byte data field of both Rx incoming message and the contents
of PL1 register are selected for matching. Mask length must be in accordance with the
expected range of DLC values. For maximum range, minimum range, and inside range
comparisons, the payload mask is not considered.
When a remote frame is received by FlexCAN and CTRL1[FCS] is configured to select
the payload comparison, the payload filtering is not considered and the comparison
results in a mismatch.
Rx incoming messages can also be filtered based upon the quantity and rate of message
reception, specifically:
Chapter 49 FlexCAN
MWCT101xS Series Reference Manual, Rev. 3, 07/2019
NXP Semiconductors 1671