Method and apparatus capable of trimming a nonvolatile semiconductor storage device without any superfluous pads or terminals

摘要

In a semiconductor storage device including a differential circuit which compares a voltage outputted by a memory cell array 103 with a voltage outputted by a reference circuit 106, a constant current source circuit 109 is connected to the differential circuit 201 in parallel with the memory cell array 103 and outputs a signal for monitoring the threshold voltage of the reference circuit 106. A controller circuit 108 is changed over from an output signal of the memory cell array 103 to that of the current source circuit 109 on monitoring the reference circuit. <IMAGE>