The AY0438 is a CMOS integrated device that drives a liquid crystal display， usually under microprocessor control. The part acts as a smart peripheral that drives up to 32 LCD segments. It needs only three control lines due to its serial input construction. It latches the data to be displayed and relieves the microprocessor from the task of generating the required waveforms. The AY0438 can drive any standard or custom parallel drive LCD display， whether it be field effect or dynamic scattering; 7-， 9-， 14- or 16-segment characters; decimals; leading + or -; or special symbols. Several AY0438 devices can be cascaded. The AC frequency of the LCD waveforms can either be supplied by the user or generated by attaching a capacitor to the LCD input， which controls the frequency of an internal oscillator. The AY0438 is available in 40-lead dual in-line plastic and 44-lead PLCC packages. Unpackaged dice are also available.