在QL4数据手册第148页:
CHKMOD must be written (if desired) only after the reception of an identifier and before the reception or transmission of data bytes. Writing this bit to a one clears the current checksum calculation. The one exception is when a byte framing error is detected and the checksum calculation should be reset. (See Byte Framing Error description in section 14.8.6.1 LIN
Mode Operation.)
This bit controls whether the SLIC module is sending or receiving data bytes. This bit is automatically reset to 0 after a transmit operation is complete or an error is encountered and transmission has been aborted. |