Patent ID: 6107874
Filing Date: 2000-08-22
Classification: H01L

Abstract:
A semiconductor integrated circuit device having a plurality of operating states, wherein a default operating state is set during the fabrication process and a remainder of operating states are selectively activated through application of an instruction signal, said semiconductor integrated circuit device, comprising:a main circuit, formed in a first area of said semiconductor chip, having a plurality of sub-circuits which are selectively activated by a first control signal to form an electric circuit from said plurality of sub-circuits;a plurality of input signal pads formed in said first area and connected to said main circuit so as to supply an input signal to said main circuit;a plurality of output signal pads formed in said first area and connected to said main circuit so as to provide an output signal from said main circuit;a mode selector formed within said first area and having a plurality of master switches therein, each of said master switches being set to a pre-determined position for receiving at least one of a potential level and a second control signal in order to maintain the default operating state, and wherein a value of the second control signal determines the operating state of said mode selector, changing said first control signal outputted from said mode selector to selectively activate said sub-circuits; anda mode changer formed in a second area, comprising an input signal pad formed in the second area of said semiconductor chip and a control signal generator which is connected between said input signal pad of said second area and said mode selector of said first area, wherein said control signal generator receives an instruction of a potential level to produce said second control signal outputted to said mode selector, said second control signal being selectable and said master switches being set to cause said mode selector to output the first control signal having different values which correspond to different operating states.