Patent ID: 7262642

Claim:
A semiconductor integrated circuit comprising: first and second transmission systems, having input ends thereof connected in common to a signal input terminal for receiving an input signal, each including a plurality of transistors and having substantially identical logic configuration; and an output select unit, receiving outputs from said first and second transmission systems, for selecting an output; wherein said plurality of transistors constituting said first transmission system comprise transistors having relatively high threshold values and being turned off and transistors having relatively low threshold values and being turned on, when the input signal supplied to said first transmission system assumes a first value; and said plurality of transistors constituting said second transmission system, comprise transistors having relatively high threshold values and being turned off and transistors have relatively low threshold values and being turned on, when an input signal supplied to said second transmission system assumes a second value; said first and second transmission systems being set to an operation mode and to a standby mode, responsive to a control signal received; and wherein said output select unit outputs from an output terminal thereof an output of the transmission system where the relatively low threshold transistors are in an on-state, when said first and second transmission systems are in the operation mode, and said output select unit cuts off an output of the transmission system with an unstable output and outputs from said output terminal an output of the transmission system with a stable output, when said first and second transmission systems are in the standby mode.