Semiconductor device for outputting data read from a read only storage device

• Main Authors: HAYASHI MITSUAKI, NAKAYA SHUJI
• Format: Patent
• Language: English
• Published: 03.07.2007
• Subjects: BASIC ELECTRIC ELEMENTS; CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INFORMATION STORAGE; PHYSICS; SEMICONDUCTOR DEVICES; STATIC STORES

A semiconductor device for outputting data read from a read only storage device, includes a plurality of read only storage devices, each including memory cells, a plurality of selecting signal lines for transmitting selecting signals to the read only storage devices for indicating a read only storage device storing data to be read, an address signal line for transmitting an address signal to the read only storage devices for indicating an address of memory cells storing data to be read and a switching device. The switching device has an address storage circuit for storing address information of a defective memory cell and detecting whether or not selected memory cells include a defective memory cell, a data storage circuit for storing replacement data for memory cells including a defective memory cell, and a switching circuit. The switching circuit inputs data from memory cells of a selected read only storage device and replacement data and outputs the data from the memory cells of the selected read only storage device and replacement data instead of data from the selected read only storage device which is stored in memory cells including a defective memory cell.