Patent ID: 7660996

Claim:
An electronic system comprising an electronic apparatus and a unit removably attached to said electronic apparatus, wherein said electronic apparatus includes: a dividing part which divides data, which is to be transmitted, into fixed-length sub-data; a generating part which generates a fixed-length packet by appending a termination identifier, which is for representing a termination point of the sub-data, to the sub-data; a first transmitting part which transmits the generated packet to said unit; a first receiving part which receives sub-data for authentication from said unit; and an authenticating part which authenticates said unit based upon the received sub-data and the sub-data that was included in the packet and transmitted; and said unit includes: a second receiving part which receives the packet from said electronic apparatus; a detecting part which executes a first data error detection based upon the termination identifier included in the received packet; a data converting part which, if data error has not been detected by said detecting part, converts sub-data, which has been extracted from the received packet, to sub-data for authenticating said unit; and a second transmitting part which transmits sub-data for authenticating said unit to said electronic apparatus if data error has not been detected, and sends said electronic apparatus data for notifying of the fact that an error has occurred if data error has been detected.