| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress the fluctuation of the threshold voltage of each memory cell, and to reduce writing time in a non-volatile semiconductor storage for electrically writing data. SOLUTION: A writing circuit 6 is constituted of an Nch transistor MN whose source is connected to the drain of Y gates MY1-MY3, and its drain is connected to a power supply 11 via a resistor RL, a level shifter circuit 7 where the drain voltage VL of the Nch transistor MN is inputted and a write completion signal is outputted when the drain voltage VL reaches a preset write completion decision level, and a write operation switching circuit 8 where a write control signal and the write completion signal of the level shifter circuit 7 are inputted, the Nch transistor MN is turned on in response to the write control signal for starting write operation, and the Nch transistor MN is turned off in response to the write completion signal 7 of the level shifter circuit for ending write operation.</p> |
