AT89S51 chip has a high gain inverse amplifier, Used to form an oscillator. xtal1, input of inverter amplifier xtal2. output A stable self-excited oscillator can be composed by bridging the quartz crystal oscillator and two capacitors at both ends. The capacitance C1 and C2 are usually around 30 pf, can stabilize the frequency and fine tune the oscillation frequency. The frequency range of oscillating pulses FOSC = mhz.024 Reset is the initialization operation of single chip microcomputer. The main function is to initialize the PC to H,0000 Enable MCU from 0000 H unit to execute the program. Except for the normal initialization of the system, When the system is in a deadlock state due to a program running error or an operation error, To get out of trouble, also need to press reset key to restart. Therefore, Reset is an essential part of MCU. This design adopts the combination of manual reset and power-on automatic reset.The power supply reset is realized by connecting the power supply at the moment of charging the capacitor. At the moment of power on, the capacitor is charged by resistance, and the first end appears positive pulse to reset. As long as the rise time of the power supply is not more than 1 ms,, the power supply can be reset automatically, and the manual reset is realized by turning on the button switch. The following is an analysis of all parts of the control system