PXD10RM Datasheet, PDF (876/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

When at least one identifier filter is configured in reception and activated, and if the received identifier
matches the filter, an RX interrupt is generated after the checksum reception only.
Typically, the application has to copy the data from the BDAR to SRAM locations. To copy the data to the
right location, the application has to identify the data by means of the identifier. To avoid this and to ease
the access to the SRAM locations, the LINFlex controller provides a Filter Match Index. This index value
is the number of the filter that matched the received identifier.
The software can use the index in the IFMI register to directly access the pointer that points to the right
data array in the SRAM area and copy this data from the BDAR to the SRAM (see Figure 23-31).
Using a filter avoids the software reading the ID value in the BIDR, and configuring the direction, the data
field length and the checksum type in the BDIR.
If LINFlex cannot provide enough RX identifier filters to handle all identifiers the software has to receive
the data for, then a filter can be configured in mask mode (refer to Section 23.8.2.3, Slave mode with
identifier filtering”) in order to manage several identifiers with one filter only.
23.8.2.2.3 Data discard
When LINFlex receives the identifier, the HRF bit in the LINSR is set and, if the HRIE bit in the LINIER
is set, an RX interrupt is generated. If the received identifier does not concern the node, the software must
set the DDRQ bit in LINCR2. LINFlex returns to idle state after bit DDRQ is set.
23.8.2.2.4 Error detection
In Slave mode, the following errors are detected:
• Header error: An error occurred during header reception (Break Delimiter error, Inconsistent
Synch Field, Header Timeout).
• Bit error: During transmission, the value read back from the bus differs from the transmitted value.
• Framing error: A dominant state has been sampled on the stop bit of the currently received
character (synch field, identifier field or data field).
• Checksum error: The computed checksum does not match the received one.
23.8.2.2.5 Error handling
In case of Bit Error detection during transmission, LINFlex stops the transmission of the frame after the
corrupted bit. LINFlex returns to idle state and an interrupt is generated if the BEIE bit in the LINIER is set.
During reception, a Framing Error leads LINFlex to discard the current frame. LINFlex returns
immediately to idle state. An interrupt is generated if the FEIE bit in the LINIER is set.
During reception, a Checksum Error leads LINFlex to discard the received frame. LINFlex returns to idle
state. An interrupt is generated if the CEIE bit in the LINIER is set.
During header reception, a Break Delimiter error, an Inconsistent Synch Field or a Timeout error leads
LINFlex to discard the header. An interrupt is generated if the HEIE bit in the LINIER is set. LINFlex
returns to idle state.
23-44
PXD10 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor