| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multiport semiconductor memory device capable of sufficiently securing a static noise margin (SMN) and reducing a memory size. <P>SOLUTION: When accessing the same row, the voltage level of word lines WLA and WLB are set to a power supply voltage VDD-Vtp. When accessing different rows, the voltage level of the word line WLA or WLB is set to a power supply voltage VDD. Accordingly, when the same row is accessed from both ports PA and PB, the voltage levels of the word lines WLA and WLB are set to power supply voltage VDD-Vtp to suppress the driving current amount of a memory cell, whereby a reduction in a current ratio of a transistor is prevented. Thus, the deterioration of SNM is prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
