The HT1330 is a CMOS fabricated LSI chip designed to drive a standard three and 1/2 digit biplexed LCD for a count-up/down timer in watch applications. The watch and timer are based on a 32768Hz quartz crystal oscillator. The maximum count-down time is 20 hours with an accuracy of 1 second. The maximum count-up period is 20 hours, but the LCD will normally display a maximum period of 19 minutes and 59 seconds. If the user presses switch S2, the total count-up time in hours and minutes will be displayed. In the count-up/down mode, the real time can be seen by pressing