Table 573. Extended Message Id Filter Element Field Description - STMicroelectronics SPC572L series Reference Manual

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Table 573. Extended Message ID Filter Element Field Description

F0 Bits 31:29 EFEC[2:0]
F0 Bits 28:0
EFID1[28:0]
F1 Bits 31:30 EFT[1:0]
F1 Bits 28:0 EFID2[28:0]
Note: In case a reserved value is configured, the filter element is considered disabled.
Extended Filter Element Configuration
All enabled filter elements are used for acceptance filtering of extended frames.
Acceptance filtering stops at the first matching enabled filter element or when the end
of the filter list is reached. If EFEC = "100", "101", or "110" a match sets interrupt flag
IR[HPM] and, if enabled, an interrupt is generated.
In this case register HPMS is updated with the status of the priority match.
000 Disable filter element
001 Store in Rx FIFO 0 if filter matches
010 Store in Rx FIFO 1 if filter matches
011 Reject ID if filter matches
100 Set priority if filter matches
101 Set priority and store in FIFO 0 if filter matches
110 Set priority and store in FIFO 1 if filter matches
111 Store into Rx Buffer or as debug message, configuration of EFT[1:0] ignored
Extended Filter ID 1
First ID of extended ID filter element.
When filtering for Rx Buffers or for debug messages this field defines the ID of an
extended message to be stored. The received identifiers must match exactly, only
XIDAM masking mechanism (see
element) is used.
Extended Filter Type
00 Range filter from EF1ID to EF2ID (EF2ID ≥ EF1ID)
01 Dual ID filter for EF1ID or EF2ID
10 Classic filter: EF1ID = filter, EF2ID = mask
11 Range filter from EF1ID to EF2ID (EF2ID ≥ EF1ID), XIDAM mask not applied
This bit field has a different meaning depending on the configuration of EFEC:
1) EFEC = "001"..."110" Second ID of extended ID filter element
2) EFEC = "111" Filter for Rx Buffers or for debug messages
EFID2[10:9] decides whether the received message is stored into an Rx Buffer or
treated as message A, B, or C of the debug message sequence.
00 Store message into an Rx Buffer
01 Debug Message A
10 Debug Message B
11 Debug Message C
EFID2[8:6] is used to control the filter event pins m_can_fe[2:0] at the Extension
Interface. A one at the respective bit position enables generation of a pulse at the
related filter event pin with the duration of one m_can_hclk period in case the filter
matches.
EFID2[5:0] defines the offset to the Rx Buffer Start Address RXBC.RBSA for storage of
a matching message.
DocID027809 Rev 4
Section 44.3.6.5: Extended message ID filter
CAN Subsystem
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