| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a semiconductor device for preventing malfunction due to deterioration of the memory cell of an EEPROM represented by a flash memory, and for improving the reliability of an EEPROM. <P>SOLUTION: When data are read from a flash memory 21 divided into a plurality of blocks, a detection circuit 23 detects the deterioration of a memory cell, from the change of the writing level of data written in a flash memory 21, and the data of the block including the deteriorated memory cell are temporarily stored in an RAM 26, and stored in a prepared saving region 27. After that, when the data of the block including the deteriorated memory cell are read, the data stored in the saving region 27 are read so that the malfunction of the system due to the deterioration of the memory cell can be prevented, and the reliability of the flash memory can be improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
