Semiconductor memory device capable of recovering defective bit and a system having the same semiconductor memory device
AssigneeKabushiki Kaisha Toshiba
InventorYukihiro Urakawa
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AssigneeKabushiki Kaisha Toshiba
InventorYukihiro Urakawa
Estimating the term…
The present invention provides a semiconductor memory device capable of simplifying a test process for a memory circuit containing a nonvolatile memory while reducing an overhead of its chip area and a system incorporating the same semiconductor memory device. This semiconductor memory device comprises a proper memory cell array, a redundant memory cell with which the defective memory cell in the proper memory cell array is to be replaced, a register for holding defect information of the defective memory cell detected in the proper memory cell array temporarily; a control circuit for replacing the defective memory cell with the redundant memory cell according to the defect information of the memory cell held in the register, a redundant program array which is an expansion of the same memory cell as the proper memory cell array while sharing a column with the proper memory cell array so as to store defect information in the same column as the defective memory cell, a writing circuit for writing defect information held in the register into the redundant program array, and a reading circuit for reading the defect information stored in the redundant program array into the register.
A semiconductor memory device for replacing a defective memory cell in a proper memory cell array with a redundant memory cell provided preliminarily based on defect information so as to recover the defective memory cell, comprising:
Dependencies are inferred from the claim text.