| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device which stores multivalue data and is capable of reading out data at a high speed and writing data in optional page order. <P>SOLUTION: The nonvolatile semiconductor storage device is provided with; a memory cell array which is composed of multivalue memory cells which store multiple-page data; a data processing circuit which executes reading operation for reading out the data from the memory cell array and programming operation which writes data to the memory cell array in units of pages; and a control circuit which controls the operation of the data processing circuit. The control circuit changes the allocation of data corresponding to threshold voltage distributions of the multivalue memory cells according to the order of pages to which the programming operation is executed so that the programming operation may be executed by shifting the threshold value voltages of the multivalue memory cells in the positive direction. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
