Patent ID: 8095832

Claim:
A method for repairing a main memory, comprising the steps of: utilizing a spare memory to repair the main memory, wherein the spare memory includes a plurality of spare memory units, wherein each spare memory unit in said plurality of spare memory units has a plurality of permutations, wherein each permutation has a reparable capacity; determining a shape of a newly found defect in the main memory, wherein said newly found defect has a defective data address; allocating a first spare memory unit; determining a first permutation in the first spare memory unit, wherein the first permutation has a reparable capacity sufficient to cover said defective data address; wherein said first permutation, a corresponding spare memory address, and a covered defective data address are neither an entire row nor an entire column at a same time; and allocating a second spare memory unit to repair the newly found defect if available permutation in the first spare memory unit fail to cover the defective data address of the newly found defect.