| 摘要 |
PURPOSE:To easily extract a chip including a bit having a narrow action allowance by changing the internal voltage of a discharging circuit forcibly from an external part at the time of non-selection, preventing a discharging current from conducting, changing forcibly the internal potential of an information holding current generating circuit from the external part, decreasing an information holding current to execute a functional test. CONSTITUTION:At the time of the functional test, a current operating as a holding current, for example, a discharging current is controlled from an external part and decreased. Namely, it is realized by driving a terminal 13 for supplying the source voltage of an internal power source circuit 12 by the voltage lower than the terminal 7 of other circuit. This can easily add DELTAVEE (forward direction voltage of transistor) by providing respectively independently a power source terminal 7 and terminals 6 and 13 on a chip, connecting the 6 and 13, separating from the terminal 7, providing them and connecting them to the same terminal at the time of loading to a package. Thus, at the time of the functional test, the action allowance of a memory cell can be measured while the holding current is decreased, therefore, the detection of the memory cell having the narrow action allowance can be easily executed. |
