An eye diagram measurement device includes a first mapping circuitry, a count circuitry, a second mapping circuitry and a memory circuitry. The first mapping circuitry maps one of plurality of internal signals of an electronic device to a first data signal having a predetermined number of bits. The counter circuitry performs a counting operation according to the first data signal and a plurality of signal values associated with the predetermined number of bits, to generate a plurality of count signals. The second mapping circuitry maps the count signals respectively to a plurality of eye diagram measurement signals corresponding to a present phase. The memory circuitry stores the eye diagram measurement signals in order to provide the eye diagram measurement signals to an external system for generating an eye diagram measurement result of the electronic device.