The Solutions of Several Problems about Microcontroller Application

Microcontroller is a small computer system that integrates ALU,memory,timer,ADC,UART,etc in one chip.it can be embedded into many kinds of controllers and intelligent electronic products.It takes convenience to people with its small size and low price,so it is widely used for a long time.The technique of microcontroller application develops constantly.Now the solutions of several problems about microcontroller application are illuminated here for exchange with colleagues.The problems are:the storage of cumulating variable at power off,multi-byte division,the detection of rotating speed and the control of facilities by AC power.