Patent ID: 7477544

Claim:
A semiconductor storage device, comprising: a semiconductor storage element comprising a plurality of storage cells each capable of storing a multi-valued information more than a binary one by changing an amount of electric charge to be stored within a storage cell; a storage control unit storing storage data, each inputted digit of which is binary, in each of the storage cells as a multi-valued information for each digit; a detection unit detecting the amount of electric charge stored in the storage cell; a determination unit determining whether the read request is an authorized request; a correspondence unit relating the detected amount of electric charge to a binary value based on a predetermined definition when the read request is legal and relating the amount of electric charge equal to the amount of electric charge detected when the read request is legal to the multi-valued value when the read request is illegal; and an output unit outputting data obtained by arraying the related value in each digit as storage data requested to read.