| 摘要 |
PURPOSE:To decrease the number of elements by providing a voltage changing circuit that forms a ternary selection signal consisting of grounding potential that makes a nonvolatile memory element operate reading, writing and erasing and a positive and negative potential. CONSTITUTION:Besides a power source voltage Vcc, a negative voltage Vp is used for the reading, writing and erasing operation, and the negative voltage Vp consists of an oscillating circuit and a rectifier circuit. In memory cells M1-M4, a switch MOSFET for selecting address is omitted, and the memory cell is constituted of only one MNOS transistor to realize reading, writing and erasing operation. Accordingly, the selection/non-selection of a word line to which a gate is connected is made by a voltage changing circuit XDRV that forms the driving signals of a ternary voltage such as power source voltage Vcc, a grounding potential 0V and a negative voltage Vp corresponding to the reading writing and erasing operation. Thereby, the number of elements can be decreased. |
