Patent ID: 7941588
Filing Date: 2011-05-10
Classification: G06F

Abstract:
1. A method for controlling a nonvolatile semiconductor memory device including a first flash memory device and a second flash memory device in which data programming and/or reading is faster than said first flash memory device, said method comprising: searching a physical address of a memory cell correlated with a logical address included in an access request; accessing a memory cell designated by said physical address; creating an access count number by counting how many times a memory cell has been accessed; and transmitting data stored in said memory cell to said second flash memory device in the case where said memory cell is placed in said first flash memory device and said access count number is more than a threshold; wherein said second flash memory device is arranged using a two value NAND flash memory and said first flash memory device is arranged using a multi-value NAND flash memory of more than two values.