38.7.5 Standard Message ID Filter Element

Up to 128 filter elements can be configured for 11-bit standard IDs. When accessing a Standard Message ID Filter element, its address is the Filter List Standard Start Address SIDFC.FLSSA plus the index of the filter element (0 ... 127).

• Bits 31:30 - SFT[1:0]: Standard Filter Type

  This field defines the standard filter type.

  Table 38-13. Standard Filter Type

  Value	Name	Description
  0x0	RANGE	Range filter from SFID1 to SFID2 (SFID2 >= SFID1)
  0x1	DUAL	Dual ID filter for SFID1 or SFID2
  0x2	CLASSIC	Classic filter: SFID1 = filter, SFID2 = mask
  0x3	RES	Reserved

• Bits 29:27 - SFEC[2:0]: Standard Filter Element Configuration

  All enabled filter elements are used for acceptance filtering of standard frames. Acceptance filtering stops at the first matching enabled filter element or when the end of the filter list is reached. If SFEC = “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.

  Table 38-14. Standard Filter Element Configuration

  Value	Name	Description
  0x0	DISABLE	Disable filter element
  0x1	STF0M	Store in Rx FIFO 0 if filter matches
  0x2	STF1M	Store in Rx FIFO 1 if filter matches
  0x3	REJECT	Reject ID if filter matches
  0x4	PRIORITY	Set priority if filter matches.
  0x5	PRIF0M	Set priority and store in FIFO 0 if filter matches.
  0x6	PRIF1M	Set priority and store in FIFO 1 if filter matches.
  0x7	STRXBUF	Store into Rx Buffer or as debug message, configuration of SFT[1:0] ignored.

• Bits 26:16 - SFID1[10:0]: Standard Filter ID 1

  First ID of standard ID filter element.

  When filtering for Rx Buffers or for debug messages this field defines the ID of a standard mesage to be stored. The received identifiers must match exactly, no masking mechanism is used.

• Bits 15:11 - Reserved

• Bits 10:0 - SFID2[10:0]: Standard Filter ID 2

  This bit field has a different meaning depending on the configuration of SFEC.


  1. SFEC = “001” ... “110”: Second ID of standard ID filter element.

  2. SFEC = “111”: Filter for Rx Buffers or for debug messages.

  SFID2[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

  SFID2[8:6] is Reserved.

  SFID2[5:0] defines the offset to the Rx Buffer Start Address RXBC.RBSA for storage of a matching message.