Patent ID: 7089427

Claim:
A semiconductor storage device storing regular data and having a security function for preventing unauthorized use of the regular data, the semiconductor storage device configured for removable connection to a video game system including a video game program executing system and comprising: a first store including a first storing area for fixedly storing a first portion of the regular data and a dummy data storing area for fixedly storing dummy data in place of a second portion of the regular data, the second portion of the regular data being necessary for use of the regular data; a second store including a second storing area which has a storage capacity equal to at least a storage capacity of the dummy data storing area of the first store and fixedly stores the second portion of the regular data; and a read control circuit which is electrically connected to the video game program executing system when the semiconductor storage device is connected to the video game system, the read control circuit comparing an input address input thereto from the video game program executing system with a dummy address corresponding to an address space of the dummy data storing area, enabling reading of the first portion of the regular data from the first store when the input address and the dummy address do not correspond, and disabling the reading of the first portion of the regular data and enabling the reading of the second portion of the regular data from the second store when the input address and the dummy address correspond.