Nonvolatile semiconductor memory and method for setting replacement information in nonvolatile semiconductor memory

A method for setting replacement information in a nonvolatile semiconductor memory, wherein said nonvolatile semiconductor memory includes:

• a memory cell array which includes a plurality of main cell arrays and a plurality of redundancy cell arrays, and a replacement data cell array which stores a replacement data indicating a replacement of one of said plurality of main cell arrays by one of said plurality of redundancy cell arrays, wherein said replacement data cell array includes:
• a plurality of first storage sections, each of which corresponds to one of said plurality of redundancy cell arrays and stores a replacement confirmation data indicating whether or not said corresponding one of the plurality of redundancy cell arrays replaces one of said plurality of main cell arrays, by nonvolatile memory cells of two bits, a plurality of second storage sections, each of which corresponds to one of said plurality of redundancy cell arrays and stores an address data indicating an address for one of said plurality of main cell arrays which is replaced by said corresponding one of the plurality of redundancy cell arrays, and a first sense amplifier which outputs a comparison data indicating a comparison result between two data from said nonvolatile memory cells of two bits of each of said plurality of first storage sections, wherein said each of said plurality of first storage sections includes a first nonvolatile memory cell and a second nonvolatile memory cell as said nonvolatile memory cells of two bits, said method comprising:
• (a) setting a threshold voltage of said second nonvolatile memory cell of each of said plurality of first storage sections from an initial voltage to said second threshold voltage;
• and
• (b) setting a threshold voltage of said first nonvolatile memory cell of one of said plurality of first storage sections corresponds to said corresponding one redundancy cell array from said initial voltage to said first threshold voltage, when said corresponding one redundancy cell array replaces said one main cell array,
• wherein said first threshold voltage is a threshold voltage when a data is written in a nonvolatile memory cell, and
• said second threshold voltage is a threshold voltage between said initial voltage and said first threshold voltage.

A nonvolatile semiconductor memory comprising:

• a main cell array including memory cells;
• a redundancy cell array including memory cells to replace a defective cell of said main cell array;
• and
• a storage section storing an information of said replacement,
• wherein said storage section stores said information by using two memory cells, and
• wherein each bit of said memory cells in said storage section has at least three states as a threshold voltage.