Patent ID: 6882175
Filing Date: 2005-04-19
Classification: H03K

Abstract:
1. An inter-block interface circuit that is provided to prevent an occurrence of unsteady potential state in a predetermined portion on a signal path on which a signal is communicated between a plurality of different types of blocks packaged on a substrate in controlling for each block ON/OFF of power supplies of the plurality of different types of blocks, comprising: a pair of gate circuits comprised of a first gate circuit which is provided in a first block that transmits a signal and which operates by a power supply of the first block, and a second gate circuit which is provided in a second block that receives the signal and which operates by a power supply of the second block; and a circuit that has a function of compulsively fixing an input level of the first gate circuit or the second gate circuit respectively provided in the first block or the second block whose power supply is ON, using the power supply of the block which is ON, when the power supply of either the first block or the second block is ON and the other power supply is OFF, and thus compulsively fixing potential of an output terminal of the gate circuit.