A memory structure that can perform characterization of output data paths without accessing the main memory array includes: a plurality of output data paths; a plurality of registers coupled to the output data paths. The registers include: at least a first pattern register and a second pattern register, for respectively storing a first data pattern and a second data pattern; and at least a first mapping register, for storing a plurality of binary values, wherein each binary value indicates whether the first data pattern or the second data pattern should be mapped to a corresponding output data path.