| 摘要 |
<p>PROBLEM TO BE SOLVED: To shorten a reading time by providing two pairs of latch circuit group holding data read out from a memory cell and operating them for reading data and outputting data alter-nately. SOLUTION: When an EEPROM of power source voltage 3V is made four values system, threshold values of 0.5-0.8V, 1.5-1.8V, 2.5-2.8V are allotted to data '1', '2', '3' of negative threshold values for data '0'. At the time of read-out, a data circuit 6** tests continuity of a memory cell by applying three kinds of voltage values 1V, 2V, 0V in this order as read-out voltage, and discriminates stored data '0', '1', '2', '3'. Then, the result of sense by read-out voltage is held by using alternately a first and a second latch circuit group RT1**, RT2**, for example, the result is outputted to the outside from the other latch circuit group RT2** while the result is read in one side of latch circuit group RT1**.</p> |
