Patent ID: 7567111

Claim:
A semiconductor integrated circuit that operates at two or more supply potentials including a first supply potential and a second supply potential that is higher than the first supply potential, the semiconductor integrated circuit comprising: an internal circuit that operates at a first supply potential; an inverter that inverts a control signal fed from the internal circuit and outputs an inverted control signal, when the first supply potential is fed; a level-shifting circuit that inputs the control signal to a first input terminal while inputting the inverted control signal to a second input terminal, and outputs, from an output terminal, a level-shifted signal of the signal input to the first input terminal or the second input terminal, when the second supply potential is fed; a first input circuit that performs a logical operation on the basis of an input signal input via an input pad and a level-shifted signal output from the level-shifting circuit, when the second supply potential is fed, the first input circuit outputting a signal corresponding to the input signal when the control signal is activated, while fixing the output level when the control signal is deactivated; a second input circuit that operates on the basis of the signal output from the first input circuit when the first supply potential is fed, the second input circuit feeding a signal to the internal circuit; and a potential-fixing circuit that fixes potentials at either of the first input terminal and the second input terminal and the output terminal of the level shifting circuit, when the second supply potential is fed whereas the first potential is not fed.