Single chip microcomputer is an important branch of computer development

SCM is an important branch of computer development. According to the current development, SCM can be roughly divided into general / special type, bus type / non bus type and industrial control type / home appliance type from different angles. 1. According to the application scope of single chip microcomputer, it can be divided into general-purpose type and special-purpose type. For example, 80C51 is a general MCU, which is not designed for a special way; Special MCU is designed and produced for a class of products or even a certain product. For example, in order to meet the requirements of electronic thermometer, it integrates the functions of temperature measurement and control circuit and ADC interface into the chip. 2. The difference between bus type and non bus type lies in whether the single chip microcomputer provides parallel bus. Bus type single chip microcomputer is generally equipped with parallel address bus, data bus and control bus. These pins are used to expand parallel peripherals, which can be connected to the single chip microcomputer through the serial port. In addition, many microcontrollers have integrated the required peripheral devices and peripheral interfaces into one piece. Therefore, in many cases, the parallel expansion of the bus can be avoided, and the packaging cost and chip volume can be greatly reduced. This kind of MCU is called non bus MCU. 3. According to the general application field of single chip microcomputer, distinguish between control type and home appliance type. Generally speaking, the industrial control type has a large addressing range and strong computing power; Most single-chip computers used in household appliances are dedicated, usually with small package, low price and high integration of peripheral devices and peripheral interfaces. Obviously, the above classification is not unique and strict. For example, 80C51 single chip microcomputer is general-purpose and bus type, and can also be used in industrial control.