| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device having high data holding characteristics and a high-speed reading operation. <P>SOLUTION: In this flash memory, an address is sequentially designated by a predetermined number of times Nmax at every supply of a power supply voltage, the retention checking of the memory cell transistor MC of each address is carried out, and a memory cell transistor MC where a threshold voltage is reduced is reprogrammed. Thus, as compared with the conventional case of performing retention checking in each reading operation, a high speed of the reading operation is achieved. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
