The NJU6535 chooses numbers of common, key scan, and general purpose ports by instructions. Therefore, It drives 126 segments at 1/3 duty in use of 3 commons and 42 segments or 164 segments at 1/4 duty in use of 4 and 41. Also it provides 4 general purpose output ports maximum to drive LEDs or others directly. Furthermore, the NJU6535 can select a LCD driving voltage out of 8 steps voltage by the instruction to adjust the display contrast of LCD panel.