| 摘要 |
<p>PURPOSE: To attain page read and random read and to attain the smooth page read and high speed write in particular by changing the number of pieces of selected word lines according to read operation and write operation. CONSTITUTION: This device is provided with an array arranging rewritable memory cells M on respective crossing parts between plural word lines ML and bit lines BL not shown in figure orthogonally intersecting each other and divided to two sub-arrays l, r. Then, at the time of read operation, the word lines ML array divided are selected one by one successively, and at the time of write operation, two pieces of the word lines WL array divided are selected simultaneously. Thus, when the data by plural pages are read out continuously, a random read time in switching a page becomes no useless in appearance, and thus, the smooth rage read is performed. Further, at the time of write operation, since plural word lines array divided are selected simultaneously, a page size at the time of write operation becomes longer than the page size at the time of read operation, and thus, the high speed write is attained.</p> |
