| 摘要 |
A plurality of the P-channel transistors of Group A and a plurality of P-channel transistors of Group B are connected between the power-supply-voltage VCC and the ground, and an output signal SUBUP is obtained from the node C via two inverters. Each terminal of. Transistors of Group B is connected to the ground via N-channel first, second and third transistors. The first signals phi1 and phi2 are inputted to the gates of the first and second transistors and the output of the NOR logical circuit is inputted to the gate of the third transistor. Current performance of the P-channel transistors of Group B is adjusted to control the substrate voltage and to make the substrate voltage both higher and lower than that of normal operation by the use of the test modes. So, the substrate voltage can be changed during hold tests in a selection process to accelerate the tests and shorten the selection time.
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