The HD66712 dot-matrix liquid crystal display controller and driver LSI displays alphanumerics, numbers, and symbols. It can be configured to drive a dot-matrix liquid crystal display under the control of a serial or a 4- or 8-bit microprocessor. Since all the functions such as display RAM, character generator, and liquid crystal driver, required for driving a dot-matrix liquid crystal display are internally provided on one chip, a minimum system can be interfaced with this controller/driver. A single HD66712 is capable of displaying a single 24-character line, two 24-character lines, or four 12character lines. The HD66712 software is upwardly compatible with the LCDII (HD44780) which allows the user to easily replace an LCD-II with an HD66712. In addition, the HD66712 is equipped with functions such as segment displays for icon marks, a 4-line display mode, and a horizontal smooth scroll, and thus supports various display forms. This achieves various display forms. The HD66712 character generator ROM is extended to generate 240 5 x 8 dot characters. The low-voltage operation (2.7V) of the HD66712, combined with a low-power mode, is suitable for any portable battery-driven product requiring low power consumption.