I.C. card

Abstract

Abstract An IC card comprises a first semiconductor memory such as a 256 K bits RAM (1) for storing main data, a second semiconductor memory such as 64 K bits EEPROM (2) for storing physical information concerning the IC card, e.g., size, capacity and access time, a control circuit (3) for selectively enabling one of the first and second semiconductor memories to operate, an address BUS (5) connected to the first and second semiconductor memories, a data BUS (7) connected to the first and second semiconductor memories, and a decoder (4) for decoding a write control signal (WE) for the second semiconductor memory using part of the address signal necessary for making access to the second semiconductor memory and delivering the decoded write control signal to the second semiconductor memory. Consequently, the area in the second semiconductor memory is divided into a non-rewritable region which does not permit rewrite of the data and a writable region which permits rewrite of the data.

Inventors

• 👤 Sanemitsu c/o Mitsubishi Denki K.K. Yoshikado

Bibliographic Details