The MSC1218 is a Bi-CMOS driver for 1/3 duty vacuum fluorescent display tube. It contains a 64-bit shift register, a 63-bit latch, a 10-bit digital dimming circuit, and three grids. The MSC1218 has only three microcontroller interface signal lines: CS, D-IN, and CLOCK. The chip select function enables the D-IN and CLOCK lines to be shared with other peripheral circuits.