说明：  基于STC8951的直流稳压电源的设计程序，通过RS232串口将程序下载到51单片机上，通过控制按键来实现输出稳定直流电压的目的。
(STC8951-based DC regulated power supply design program, a program downloaded through the RS232 serial port to the microcontroller 51, through the control buttons to achieve stable DC output voltage.)