| 摘要 |
PURPOSE:To secure a power source margin, and to improve reliability for the decision of information, by switching a sense current at the readout time of an erasable P-ROM to the sense current larger than that at a program verifying time. CONSTITUTION:At the program verifying time, a transistor QL1 at the load side of a sense amplifier SA is turned on, and a QL2 is turned off, and the completion of a write is decided by a current on a memory cell transistor QM through a transistor QD at a driving side. At a normal readout time, the QL2 is also turned on in addition to the QL1, and a current is increased by heightening a current driving capacity, and the decision is performed by a large threshold current. In this way, a correct decision is performed even when a few amount of leakage is generated in electric charge accumulated at the floating gate of the transistor QM, and the reliability for the decision of the information can be improved. |
