The MN12511 is a fluorescent display tube driver LSI. It accepts data for display transferred over a serial interface, generates the digit and/or segment drive signals, and outputs those signals from 16 high-voltage ports. This LSI allows the number of digits displayed to be increased easily by the cascade connection of additional MN12511 LSIs. Also, the MN12511 does not preassign the outputs to digits or segments, so it can be used with a wide range of display types.