Semiconductor memory device and signal line shifting method

A semiconductor memory device comprising:

• a memory cell array having memory cells arranged in the form of a matrix;
• a redundant column cell array for relieving a defective column of said memory cell array;
• a decoder circuit for decoding an address to select a memory cell in said memory cell array;
• a plurality of data lines, to which data read out from said memory cell array or data to be written in said memory cell array, corresponding to a plurality of columns, is transferred by said decoder circuit;
• a spare data line, to which data read out from said redundant column cell array or data to be written in said redundant column cell array is transferred;
• and
• a data line shift circuit for shifting, one by one, data lines and said spare data line, which are arranged on one side of a data line serving as a starting point, to which data of a defective column is to be transferred when the defective column is accessed, to connect said data lines and said spare data line to data input/output lines;
• which further comprises first means for establishing a correspondence between addresses and starting points for data line shift, and second means for establishing a correspondence between data input/output line numbers and starting points for data line shift, wherein said first and second means are used for determining a form of data line shift, which is carried out by said data line shift circuit, with respect to an inputted address.

A signal line shifting method for a semiconductor memory device which comprises a memory cell array, a redundant column cell array, first signal lines corresponding to said memory cell array, and a second signal line corresponding to said redundant column cell array,

• wherein when said signal line shifting method shifts, one by one, first signal lines, which are arranged on one side of a first signal line serving as a starting point corresponding to a defective column when the defective column is accessed, to connect said first signal lines and said second signal line to input/output lines, said signal line shifting method comprises the steps of:
• establishing a correspondence between addresses and starting points for signal line shift;
• establishing a correspondence between input/output line numbers and said starting points for signal line shift;
• and
• inputting a predetermined address to compare said correspondences with each other to determine a form of signal line shift on the basis of the compared result.