ABSTRACT
This design is produced by Atmel AT89S52 microcontroller chip and AT24C02 chip (memory chip), and use as a clock chip DS1302 (with real-time display the current time, press the buzzer to set the time with timekeeping, to modify the current clock (alarm) etc.). In a microcontroller core with its peripheral devices based on the realization of the small system - Automatic ring a bell system. The so-called small system microcontroller from the system point of view to define the complex functions that the hardware and software, and tightly coupled to the computer system. Hardware design part of the circuit are described from various functions, including the power supply circuit, reset circuit, clock circuit, display circuit, password circuits. Software part is divided into four modules: initialization module, the time display module, and the regular ringing module, password circuits. Initialization module is the main mode and timer counter initial settings. Responsible for the correct time display module displays the current time. Buttons to set the module is the time of the calibration and settings. Time a bell rings when the module is responsible to the function. That is a function of the system hardware and software work together to complete two parts.
Key word: SCM Memory chips Clock chip