Hi,NXP
Phenomenon: When the LIN data segment is 8 bytes, checksum failure occurs in LIN's DMA mode.
Cause: There may be a BUG in NXP's design. When designing the data reception buffer Lpuart_Lin_Ip_au8SduBuffer, only the data segment was considered. However, in fact, the underlying code's DMA reception needs to receive both the data segment and the checksum segment, and use Lpuart_Lin_Ip_au8SduBuffer for checksum. Since Lpuart_Lin_Ip_au8SduBuffer is designed as an 8-byte array, when the LIN data field has 8 bytes of data, the ninth byte (checksum segment) cannot be received, and the data checksum will fail.
This bug still exists in RTD6.0.0 and RTD7.0.0.
Incidentally, currently there is only RX mode for LIN's DMA. Are there any plans for TX mode?
Solution. Modify the size of Lpuart_Lin_Ip_au8SduBuffer, that is, change the underlying macro definition LPUART_LIN_IP_MAX_DATA_LENGTH_U8 from 8 to 9.
Best Regards,
xianlong
