Semiconductor memory device

A semiconductor memory device comprising:

• a plurality of bit lines;
• a plurality of word lines;
• a plurality of memory cells disposed to correspond to said plurality of bit lines and said plurality of word lines;
• a row address select circuit for designating a predetermined one from said plurality of word lines;
• a column address decoder for decoding a column address signal, as received for designating a predetermined bit line from said plurality of word lines, to form a select signal of said bit lines;
• and
• a column select circuit for selecting a predetermined one from said plurality of bit lines in response to the select signal formed by said column address decoder,
• wherein said column address decoder includes:
• a first pre-decoder corresponding to a high-order address;
• a second pre-decoder corresponding to a low-order address;
• a shift register for using the output signal of said second pre-decoder as an initial value;
• and
• an output circuit for selecting either the output signal of said second pre-decoder or the output signal of said shift register in accordance with an action mode,
• whereby said select signal is formed by the output signal of said first pre-decoder and the output signal through said output circuit,
• wherein said shift register includes a first shift register for an even address and a second shift register for an odd address and forms two sets of continuous select signals of said bit lines, as composed of a sequential action and an interleave action, on the basis of said initial value by combining its up and down shifting actions, and
• wherein said second pre-decoder forms initial values corresponding individually to said even address first shift register and said odd address second shift register.

A semiconductor memory device comprising:

• a plurality of bit lines;
• a redundant bit line;
• a plurality of word lines;
• a plurality of memory cells disposed to correspond to said plurality of bit lines, said redundant bit line and said plurality of word lines;
• a row address select circuit for designating a predetermined one from said plurality of word lines;
• a column address decoder for decoding a column address signal, as received for designating a predetermined bit line from said plurality of word lines, to form a select signal of said bit lines;
• a column select circuit for selecting a predetermined one from said plurality of bit lines in response to the select signal formed by said column address decoder;
• and a redundant circuit for selecting said redundant bit line in place of said bit lines,
• wherein said column address decoder includes:
• a first pre-decoder corresponding to a high-order address;
• a second pre-decoder corresponding to a low-order address;
• a shift register for using the output signal of said second pre-decoder as an initial value;
• and
• an output circuit for selecting either the output signal of said second pre-decoder or the output signal of said shift register in accordance with an action mode,
• whereby said select signal is formed by the output signal of said first pre-decoder and the output signal through said output circuit,
• wherein said redundant circuit includes:
• a memory circuit for storing faulty addresses;
• a comparator for comparing such one of the faulty addresses stored in said memory circuit as corresponds to said high-order address and the address signal inputted;
• a redundant pre-decoder for decoding said low-order address of said faulty addresses;
• and
• a coincidence detect circuit for detecting the compared coincidence output of said comparator and a coincidence between the individual outputs of said redundant pre-decoder and said second pre-decoder, and
• wherein a predetermined bit line is selected from said redundant bit lines by said redundant bit line select circuit in response to the detected signal of said coincidence detect signal in place of the select signal formed in said column address decoder.