| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a flash memory device and its programming method by which the efficiency of reading operation and programming operation can be improved, and especially the number of times of programming operation can be reduced. <P>SOLUTION: The flash memory device having multi-level cells comprises a memory cell array, a means for previously charging bit lines, a bit line voltage supply circuit for supplying voltage to bit lines, and a 1st to 3rd latch circuits whose functions are mutually different and executes reading operation and programming operation by dividing bits into the LSB and MSM. The memory device reading method executes LSB reading operation twice and executes MSB reading operation once and the programming method executes LSB programming operation and MSM programming operation respectively once. At the time of programming operation, multi-level data can be programmed in the memory cells by performing the programming operation twice. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
