Semiconductor memory device usable as static type memory and read-only memory and operating method therefor

摘要

Each of memory cells of a semiconductor memory device comprises a transistor connected between a node and a node, a transistor connected between the node and a node, a transistor connected between a node and a node, and a transistor connected between node and a node. Each of the nodes is connected to either of a first potential line and a second supply line in a program unit when it is manufactured, and each of the nodes is connected to either of the first and the second ground lines in a program unit when it is manufactured. A supply potential is supplied to the first supply line, and the supply potential or the ground potential is selectively supplied to the second supply line. The ground potential is supplied to the first ground line, and the ground potential or the supply potential is selectively supplied to the second ground line.