The microcontroller is also known as a microcontroller because it was first used in the field of industrial control. Microcontrollers evolved from specialized processors that had only a CPU on a chip. The earliest design concept was to integrate a large number of peripheral devices and CPUs into a single chip, making the computer system smaller and easier to integrate into complex and demanding control devices.INTEL's Z80 was the first processor to be designed according to this idea, and since then, the development of microcontrollers and specialized processors have gone their separate ways.
Early microcontrollers were 8-bit or 4-bit. The most successful of these was INTEL's 8031, which received great acclaim for its simplicity, reliability, and performance. Since then, the MCS51 series of microcontroller systems have been developed on the 8031. The microcontroller system based on this system is still widely used until now. With the improvement of the requirements of the industrial control field, 16-bit microcontroller began to appear, but because of the price-performance ratio is not ideal and has not been widely used. 90's with the development of consumer electronics products, microcontroller technology has been greatly improved. With the INTEL i960 series, especially the later ARM series of widely used, 32-bit microcontrollers quickly replace the high-end status of 16-bit microcontrollers, and enter the mainstream market. The performance of the traditional 8-bit microcontroller has also been improved rapidly, and the processing power has been increased hundreds of times compared with that of the 80s. At present, the high-end 32-bit microcontroller main frequency has exceeded 300MHz, performance to catch up with the mid-90's dedicated processor, while the common model factory price fell to 1 U.S. dollars, the highest-end model is only 10 U.S. dollars. Contemporary microcontroller systems are no longer developed and used only in bare-metal environments, and a large number of specialized embedded operating systems are widely used on a full range of microcontrollers. The high-end microcontrollers processed as the core of handheld computers and cell phones can even directly use dedicated Windows and Linux operating systems.
Microcontrollers are best suited for embedded systems than dedicated processors, which is why they are used the most. In fact microcontrollers are the most numerous computers in the world. Microcontrollers are integrated in almost every electronic and mechanical product used in modern human life. Cell phones, telephones, calculators, household appliances, electronic toys, palmtop computers, and computer accessories such as mice are equipped with 1-2 microcontrollers. Personal computers also have a number of microcontrollers working in them. Automobiles are generally equipped with more than 40 microcontrollers, and complex industrial control systems may even have hundreds of microcontrollers working at the same time! The number of microcontrollers not only far exceeds the combined number of PCs and other computing, but is even greater than the number of humans.
Introduction of microcontroller
Microcontroller, also known as a single microcontroller, it is not the completion of a logical function of the chip, but a computer system integrated into a chip. To summarize: a chip becomes a computer. Its small size, light weight, inexpensive, for learning, application and development to provide a convenient condition. At the same time, learning to use a microcontroller is the best choice to understand the principles and structure of the computer.
Microcontroller internal and computer functions similar to the module, such as the CPU, memory, parallel bus, and hard disk role of the same memory components, the difference is that the performance of these components are relative to our home computer is much weaker, but the price is also low, generally no more than 10 yuan can be .... Use it to do some control of electrical appliances of a class is not very complex work enough. We now use the automatic drum washing machine, smoke hood, VCD and other home appliances can be seen inside its figure! .... It is mainly as the core component of the control part.
It is an online real-time control computer, online is the field control, the need is to have a strong anti-interference ability, lower cost, which is also and offline computer (such as home PC) the main difference.
The microcontroller is dependent on the program, and can be modified. Through different programs to achieve different functions, especially special unique features, which is other devices need to be very hard to do, and some are very difficult to spend a lot of effort to do. A not very complex function if the United States developed in the 1950s 74 series, or the 1960s CD4000 series of these pure hardware to deal with, the circuit must be a large PCB board! But if you use the series of microcontrollers that were successfully marketed in the 70's in the US, the results will be very different! Only because the microcontroller through your program can achieve high intelligence, high efficiency, and high reliability!
Because microcontrollers are cost-sensitive, the dominant software is still the lowest level of assembly language, which is in addition to the binary machine code above the lowest level of language, since it is so low why use it? Many high-level language has reached the level of visual programming why not use it? The reason is very simple, is that the microcontroller does not have a home computer like the CPU, there is no hard disk like the mass storage device. A small program written in a visual high-level language, even if there is only one button, will reach the size of tens of K. For the hard disk of a home PC, it's nothing! This is nothing for the hard disk of a home PC, but it is unacceptable for a microcontroller. Microcontrollers have to be very efficient in the utilization of hardware resources, so assembly is used a lot, even though it is primitive. In the same way, if you take the operating system and application software from a giant computer and run it on a home PC, the home PC can't handle it.
It can be said that the twentieth century spanned three "electric" eras: the electrical era, the electronic era, and now the computer era. However, this computer, usually refers to a personal computer, or PC for short. It consists of a mainframe computer, a keyboard, a monitor, and so on. There is another type of computer that most people are not so familiar with. This type of computer is a microcontroller (also known as a microcontroller) that gives intelligence to various machines. As the name implies, the smallest system of this type of computer uses only a single integrated circuit for simple operations and control. Because of its small size, usually hidden in the controlled machinery "belly". It is in the whole device, plays a role as the role of the human mind, it went wrong, the whole device is paralyzed. Now, the use of this microcontroller has been a very wide range of areas, such as intelligent instrumentation, real-time industrial control, communications equipment, navigation systems, household appliances and so on. Once a variety of products with a microcontroller, you can play a role in upgrading the effectiveness of the product, often in the product name before the title of the adjective - "intelligent", such as intelligent washing machines and so on. Now some factory technicians or other amateur electronics developers to come up with certain products, either the circuit is too complex, or too simple and easy to imitate the function. The reason for this, may be stuck in the product does not use a microcontroller or other programmable logic devices.
Microcontroller applications
At present, microcontrollers penetrate into all areas of our lives, it is almost difficult to find any field without a trace of microcontroller. Missile navigation devices, aircraft on a variety of instrumentation control, computer network communications and data transmission, industrial automation process of real-time control and data processing, the widespread use of a variety of intelligent IC cards, civilian limousine safety systems, video recorders, cameras, automatic washing machine control, and program-controlled toys, electronic pets, etc., these are inseparable from the microcontroller. Not to mention the automatic control field of robotics, intelligent meters, medical equipment. Therefore, the study, development and application of microcontroller will create a number of computer applications and intelligent control of scientists and engineers.
Microcontroller is widely used in the field of instrumentation, household appliances, medical equipment, aerospace, intelligent management of special equipment and process control, etc., which can be broadly divided into the following categories:
1. Widely used in instrumentation, combined with different types of sensors, can be realized such as voltage, power, frequency, humidity, temperature, flow, speed, thickness, angle, length, hardness, elements, pressure and other physical measurements. The use of microcontroller control makes instrumentation digital, intelligent, miniaturized and more powerful than with electronic or digital circuits. For example, precision measurement equipment (power meter, oscilloscope, various analyzers).
2. Application in industrial control
With microcontroller can constitute a variety of control systems, data acquisition systems. For example, intelligent management of factory assembly lines, intelligent control of elevators, various alarm systems, and computer networking to form a secondary control system.
3. Application in household appliances
It can be said that nowadays all household appliances are basically controlled by microcontroller, from the rice cooker, washing machine, refrigerator, air-conditioner, color TV, other audio-video equipment, and then to the electronic weighing equipment, a variety of ubiquitous.
4. Application in the field of computer networks and communications
Modern microcontroller generally has a communication interface, it can be very convenient to communicate with the computer data, for the application of computer networks and communications equipment provides excellent material conditions, now the communication equipment basically realize the intelligent control of the microcontroller from the cell phone, telephone, small program-controlled switches, buildings, automatic communication call systems, trains, wireless communication equipment, and so on. Automatic communication call system, train wireless communication, and then to the daily work everywhere in the cell phone, trunking mobile communication, radio intercom and so on.
5. Microcontroller in the field of medical equipment
Microcontroller in the medical equipment in a wide range of uses, such as medical respiratory machine, a variety of analyzers, monitors, ultrasound diagnostic equipment and bed call system and so on.
In addition, the microcontroller in the industrial and commercial, financial, scientific research, education, defense and aerospace fields have a very wide range of uses.
Microcontroller learning:
At present, many people do not recognize the assembly language. It can be said that it is important to master the use of C language microcontroller programming, can greatly improve the efficiency of development. However, if the beginner does not understand a little bit of assembly language for microcontrollers, in the field of microcontrollers is more fatal. If you do not take into account the hardware resources of the microcontroller, in KEIL with C haphazard programming, the result can only be out of the problem can not be solved! It can be said with certainty that the best C language microcontroller engineers are from the assembly out of the programmer because the C language of the microcontroller although it is a high-level language, but it is different from the desktop PC on the VC + + + and what the hardware resources of the microcontroller is not very powerful, unlike us with VC, VB and other high-level language on the desktop PC to write the program on the desktop PC after all, desktop computers are very powerful hardware, so it can be not to consider the issue of hardware resources. Consider the problem of hardware resources.