| 摘要 |
PURPOSE:To lower current density in a word line remarkably by dividing a memory cell array, a current source for driving, pairs of word lines, and pairs of bit lines into plural blocks, and lowering word line current in each block in reverse proportion to the number of division. CONSTITUTION:A memory cell array, a current source for driving, pairs of word lines and pairs of bit lines are divided into plural number of blocks. The number of division to make blocks is >=2. When dividing into two, the pairs of word lines are divided into WL1 and WL2, the memory cell array is divided into MCA1 and MCA2, and the current source for driving is divided into IS1 and IS2. A word driver Qwd1 is connected to the first block, and a word driver Qwd2 is connected to the second block. Thus, the peak value of current density distribution of divided word lines WL1, WL2 becomes about Imx/2, that is, about a half of coventional value. In this case, the word driver Qwd2 is controlled on (when selecting) and off (when not selecting), a signal (controlling input) added to the base is given from another end of the word line WL1. |
