KEYLESS ENTRY SYSTEM, TRANSMITTER AND RECEIVER

摘要

PROBLEM TO BE SOLVED: To reduce the number of writings to a non-volatile memory provided in a transmitter.

SOLUTION: The transmitter increases a first numerical value stored in a volatile memory according to regulation and transmits the first numerical value wirelessly. The receiver receives the first numerical value and outputs a signal indicating authentication is correctly executed when the first numeral value is above a second numeral value stored in the memory and enables the second numerical value to be updated to the first numerical value. The transmitter writes in the non-volatile memory a third numerical value obtained by adding a predetermined numerical value to the first numerical value each time the first numerical value increases by a predetermined numerical value. The transmitter reads out the third numerical value stored in the non-volatile memory and writes the third numerical value in the volatile memory as the first numerical value when the first numerical value stored in the volatile memory is deleted by battery replacement or the like.

COPYRIGHT: (C)2006,JPO&NCIPI