Patent ID: 6167540
Filing Date: 2000-12-26
Classification: G11C

Abstract:
A semiconductor memory device comprising:a normal memory constituted by a plurality of normal memory cells;a redundant memory constituted by a plurality of redundant memory cellsa predecoder for decoding an address signal and outputting a corresponding address selection signal to an array interconnection;a normal address decoder for selecting a normal memory cell in said normal memory on the basis of an address selection signal sent from said predecoder through said array interconnection;a redundant address decoder for selecting a redundant memory cell in said redundant memory on the basis of an address selection signal sent from said predecoder through said array interconnection; andcontrol means for, when a defective normal memory cell in said normal memory is designated by the address signal, outputting to said predecoder, an inactivating signal for inactivating said normal memory and a redundant memory cell selection signal for selecting said redundant memory cell in said redundant memory in place of said defective normal memory cell in said normal memory, wherein:said predecoder outputs an address selection signal corresponding to the redundant memory cell selection signal from said control means to said array interconnection of the basis of the inactivating signal and the redundant memory cell selection signal from said control means,said predecoder comprises at least first and second predecoder units for receiving predetermined bit signals formed by dividing the address signal constituted by a plurality of bit signals, and outputting the address selection signals to first and second interconnections constituting said array interconnections,said first predecoder unit comprising first arithmetic means for determining selection of said normal memory or said redundant memory upon receiving the inactivating signal from control means, outputting an address selection signal corresponding to the address signal to said first interconnection of said array interconnections when said normal memory is to be selected, and outputting an address selection signal for inactivating said normal memory to said first interconnection of said array interconnections when said redundant memory is to be selected, andsaid second predecoder unit comprising second arithmetic means for determining selection of said normal memory or said redundant memory upon receiving the inactivating signal and the redundant memory cell selection signals from said control means, outputting an address selection signal corresponding to the address signal to said second interconnection of said array interconnections when said normal memory is to be selected, and outputting an address selection signal corresponding to the redundant memory cell selection signals to said second interconnection of said array interconnections on the basis of the logic between the inactivating signal and the redundant memory cell selection signals from said control means when said redundant memory is to be selected.