CPU is composed of controller, arithmetic and register. The central processing unit (CPU) mainly includes the arithmetic unit and the cache and the bus that realizes the data, control and state of the connection between them. Central processing unit CPU, internal memory and input\/output devices together are called the three core components of electronic computers. The central processing unit (CPU) is a large scale integrated circuit, which is the computing core and control core of a computer. Its main function is to interpret computer instructions and process data in computer software. The CPU takes instructions from the memory or cache, puts them into the instruction register, and decodes the instructions.
It breaks the instruction into a series of microoperations, and then issues various control commands to execute a series of microoperations to complete the execution of an instruction.