Patent ID: 7002834

Claim:
A semiconductor integrated circuit comprising: a normal power supply line to which a power supply voltage is constantly supplied; a virtual power supply line; a first switch that connects said normal power supply line and said virtual power supply line in response to activation of a switch control signal; a switch control circuit that maintains the activation of the switch control signal during a normal operation mode and inactivation of the switch control signal during a low power mode; a first circuit block connected to said virtual power supply line at its power supply terminal; a second circuit block connected to said normal power supply line at its power supply terminal; and a floating prevention circuit disposed between an output of said first circuit block and an input of said second circuit block, wherein said floating prevention circuit has a second switch that connects a connecting node to a first voltage line in response to the inactivation of the switch control signal, and interrupts the connection between the connecting node and the first voltage line in response to the activation of the switch control signal, said connecting node being between the output of said first circuit block and the input of said second circuit block.