Patent ID: 6894545

Claim:
An integrated circuit, comprising: a first circuit block in which a first power supply is controlled; and a second circuit block which has logical circuit and in which a second power supply is always supplied, wherein when said first power supply is broken, a mask signal output to said second circuit block from said first circuit block is changed into low level from high level in order to cut off output signals of said first circuit block, wherein said second circuit block includes: a first node on which said mask signal is supplied; a first latch circuit which is formed by a first logical gate and a second logical gate, wherein said first logical gate inputs said first power supply and said mask signal, said second logical gate inputs a output signal of said first logical gate, and the output terminal of said second logical gate and the input terminal of said first logical gate are connected with said first node, wherein said first latch circuit keeps the level of said first node when said first power supply in said first circuit block is effective with respect to said second logical gate; and outputs a low level signal to said first node when said first power supply in said first circuit block is ineffectual.