LIN Controller (LINFlex)
MPC5606S Microcontroller Reference Manual, Rev. 7
Freescale Semiconductor 873
• 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.
23.8.2.2.6 Valid header
A received header is considered as valid when it has been received correctly according to the LIN protocol.
If a valid Break Field and Break Delimiter come before the end of the current header or at any time during
a data field, the current header or data is discarded and the state machine synchronizes on this new break.
23.8.2.2.7 Valid message
A received or transmitted message is considered as valid when the data has been received or transmitted
without error according to the LIN protocol.
23.8.2.2.8 Overrun
Once the message buffer is full, the next valid message reception leads to an overrun and a message is lost.
The hardware sets the BOF bit in the LINSR to signal the overrun condition. Which message is lost
depends on the configuration of the RX message buffer:
• If the buffer lock function is disabled (RBLM bit in LINCR1 cleared) the last message stored in
the buffer is overwritten by the new incoming message. In this case the latest message is always
available to the application.
• If the buffer lock function is enabled (RBLM bit in LINCR1 set) the most recent message is
discarded and the previous message is available in the buffer.
23.8.2.3 Slave mode with identifier filtering
In the LIN protocol the identifier of a message is not associated with the address of a node but related to
the content of the message. Consequently a transmitter broadcasts its message to all receivers. On header
reception a slave node decides—depending on the identifier value—whether the software needs to receive
or send a response. If the message does not target the node, it must be discarded without software
intervention.
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