DOUBLE PORT SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE: A double port semiconductor memory device is provided to reduce an area occupied by an isolation area formed at a boundary between a N-well and a P-well. CONSTITUTION: A semiconductor substrate includes a memory cell divided into a N-well and a P-well. The semiconductor memory device includes the first word line, the second word line, the first bit line and the second bit line. The first CMOS inverter includes the first NMOS transistor(N1), the first PMOS transistor(P1) and an input terminal and an output terminal. The second CMOS inverter includes the second NMOS transistor(N2), the second PMOS transistor(P2) and an input terminal and an output terminal. The third NMOS transistor(N3) has a gate connected to the first word line, and a drain connected to the first bit line and a source connected to the first memory node(N1). The fourth NMOS transistor(N4) has a gate connected to the first word line, a drain connected to the first bit line and a source connected to the second memory node(N2). The fifth NMOS transistor(N5) has a gate connected to the first memory node and a source connected to a ground line. And the sixth NMOS transistor(N6) has a gate connected to the second word line, a source connected to the drain of the fifth NMOS transistor and a drain connected to the second bit line.