A memory device comprising a memory core including a
memory cell array including a plurality of memory cells, the
memory cell array being divided into a plurality of memory banks, a Built-In
Self Test (BIST) circuit configured to select a target
memory bank from the plurality of memory banks and perform a parallel test on the target
memory bank, and a
control circuit configured to control the parallel test. The BIST circuit may determine at least one defective
memory cell outputting a defective bit among target memory cells included in the target
memory bank, and may determine whether the defective memory
cell is a single defective memory
cell or an adjacent double defective memory
cell, and the
control circuit May determine the target memory
bank to be a defective memory
bank when the defective memory cell is not the single defective memory cell and the adjacent double defective memory cell.