A modular Renesas singlechip experimental system is developed to design digital thermometer.The system uses highly integrated temperature sensor,adopts modular design scheme and completes the thermometer design which is based on 16-bit singlechip microcontroller(M3062LFGPGP).A new algorithm is introduced to process temperature data.Temperature measuring precision could be improved by using main control software and appropriate hardware correction technique.According to traditional design principles and the characteristics of Renesas microcontrollers M3062LFGPGP,the system integrates A/D converter module and calendar module into the main control module,and uses software program instead of the above-mentioned two hardware modules and realize their functions simultaneously.The system consists of control module,temperature module and display module.The system can display the current temperature with time like year,month,day,week,hour,minute,second,etc.This design can significantly reduce system's power consumption and decrease hardware design errors,thus improve system stability.This digital thermometer can accurately measure and clearly display the current temperature and time,which is highly valuable in application.