PXS20RM Datasheet, PDF (989/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

LIN Controller (LINFlexD)
Submode
Identifier list
Mask
Table 31-3. Filter submodes
Description
Both filter registers are used as identifier registers. All bits of the
incoming identifier must match the bits specified in the filter register.
This is the default submode for the LINFlexD controller.
The identifier registers are associated with mask registers specifying
which bits of the identifier are handled as “must match” or as “don’t
care”.
The bit mapping and register organization in these two submodes is shown in Figure 31-9.
Identifier filter register organization
Identifier
Bit Mapping
IFCR_x
DFL DIR CCS
ID
Identifier
Identifier
Identifier filter configuration
Identifier list submode
IFCR_2n
IFCR_2n+1
Identifier filter submode
IFM = 0
Identifier
Mask
Mask submode
IFCR_2n
IFCR_2n+1
IFM = 1
Figure 31-9. Filter configuration - register organization
31.7.3.2 Identifier filter submode configuration
The identifier filters are configured in the IFCR registers. To configure an identifier filter the filter must
first be deactivated by clearing the corresponding bit in the IFER[FACT] field. The submode (identifier
list or mask) for the corresponding IFCR register is configured by the IFMR[IFM] field. For each filter,
the IFCR register is used to configure:
• The ID or mask
• The direction (TX or RX)
• The data field length
• The checksum type
If no filter is active, an RX interrupt is generated on any received identifier event.
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
31-13