Repair bits for a low voltage cache

A method and apparatus for repairing cache memories/arrays is described herein. A cache includes a plurality of lines and logically viewable in columns. A repair cache coupled to the cache includes a repair bit mapped to each logically viewable column. A repair module determines a bad bit to be repaired within a column based on any individual or combination of factors, such as the number of errors per line of the cache, the number of errors correctable per line of the cache due to error correction code (ECC), the failure rate of bits, or other considerations. The bad bit is transparently repaired by the repair bit mapped to the column including the bad bit, upon an access to a cache line including the bad bit.