Patent Number: 6,167,483

Title: Block erase type nonvolatile semiconductor memory device

Abstract: When the number of times erasure is performed in a first erase block in which data is to be written exceeds a predetermined number of times, a second erase block is determined for replacing data in the first erase block with data in the second erase block, and the erase number (the number of times erasure is performed) stored in the second erase block is read into a buffer. If the erase number read into the buffer is less than a certain value, data stored in the second erase block is read into the buffer. The number of the second erase block is stored in a first offset of a sub address conversion table read into a work buffer, and the number of the first erase block is stored in a second offset to replace data in the first and second erase blocks with each other.

Inventors: Miyauchi; Shigenori (Hyogo, JP)

Assignee: Mitsubishi Denki Kabushiki Kaisha

International Classification: G06F 12/02 (20060101); G11C 16/06 (20060101); G11C 16/34 (20060101); G06F 012/02 ()

Expiration Date: 12/26/2017