Semiconductor memory device

摘要

A semiconductor device comprises a memory cell; a data line connected to the memory cell; voltage supplying means for supplying a supply voltage; first control signal input means for entering a first control signal for giving an instruction to generally read a data from the memory cell; second control signal input means for entering a second control signal for giving an instruction to discriminate a current value of a current flowing through the memory cell; current detecting means connected to the first and second control signal' input means, the voltage supplying means and the data line, for detecting a current flowing from the voltage supplying means to the data line by using a level sensing current according to the supply voltage in response to the first and second control signals; and level switching means connected to the second control signal input means, for switching the level sensing current so that a difference in a current value between the current detected by the current detecting means and the current flowing through the memory cell in the discrimination under instruction of the second control signal is smaller than a difference therebetween in a general reading operation. Owing to the configuration of the semiconductor device, it is possible to perform strict discrimination with sufficient margin included when it is confirmed whether or not an on state or an off state of the memory cell is appropriately set. <IMAGE>