57.7.8.9 Identifier Parity

A protected identifier consists of two subfields: the identifier and the identifier parity. Bits 0 to 5 are assigned to the identifier, and bits 6 and 7 are assigned to the parity.

The USART interface can generate/check these parity bits, but this feature can also be disabled. The user can choose between two modes via the FLEX_US_LINMR.PARDIS bit:

• PARDIS = 0:
  • During header transmission, the parity bits are computed and sent with the six least significant bits of the IDCHR field of the LIN Identifier register (FLEX_US_LINIR). Bits 6 and 7 of this register are discarded.
  • During header reception, the parity bits of the identifier are checked. If the parity bits are wrong, an Identifier Parity error occurs (see Parity). Only the six least significant bits of the IDCHR field are updated with the received Identifier. Bits 6 and 7 are stuck to 0.
• PARDIS = 1:
  • During header transmission, all the bits of the IDCHR field of the LIN Identifier register (FLEX_US_LINIR) are sent on the bus.
  • During header reception, all the bits of the IDCHR field are updated with the received Identifier.