| 摘要 |
<p>PURPOSE:To increase the reading speed of a momery cell, by discharging the column line before selection of the memory cell and then stopping the discharge after detecting that the column line is discharged down to a prescribed level of potential. CONSTITUTION:When address signals A0-Am vary, the signal DI is turned to ''1'' to turn on transistors (TRs) 280-28m+1. Then a discharge is started for column line 200-20m and a control line B. When control lines B and RI are set at ''0'', the output of a NOR circuit 31 is set at ''1''. Thus the output signal DI of a pulse control circuit 29 is set at ''0'' to turn off TRs 280-28m+1. For instance, if a row line 191 and a column line 211 are designated with a cell 1811 selected each, the TR811 is turned on as far as no electron is injected into a floating gate of a transistor that forms this memory cell. Thus a column line 201 is discharged, and a signal of level ''0'' is delivered via an output circuit 27. The output is quickly set at the ''0'' level since the line 201 is already discharged.</p> |
