The ML9092-01/02/03/04 are LCD drivers that have internal RAM and a key scan function. They are best suited for car audio displays. Since 1-bit data of the display data RAM corresponds to the light-on or light-off of 1-dot of the LCD panel (a bit map system), a flexible display is possible. A graphic display system of a maximum of 60 × 10 dots (56 × 10 dots for ML9092-01, 60 × 10 dots for ML9092-02/03/04). can be implemented. The ML9092-01/02 do not require any power supply circuit to drive the LCD, because they have internal voltage doublers. (If a large-sized panel is driven, use the ML9092-03, to which the LCD driving voltage is supplied externally.) The internal key scan circuit (5 × 5 key scanning for ML9092-01/04, 6 × 4 key scanning for ML9092-02/03) has eliminated the needs of key scanning by the CPU, thereby enabling the efficient use of the CPU ports.