Reference:
Teacher Zhu Youpeng's information: https://zhuanlan.zhihu.com/p/126273015
1. What is a microcontroller
The essence of SCM is a kind of computer.
What is a computer? A computer is an electronic system that contains CPU, memory, and certain peripherals (IO pins, network ports, I2C interfaces, serial ports, etc.) on the hardware, and can run certain programs.
There are many kinds of computers. The big one is as big as a super budget, a few rooms are as big. Everyone is familiar with the small ones such as personal computers, desktops and laptops, and the smallest ones, such as tablets and mobile phones, are all computers. No matter how small a smart watch is, it is also a computer. As long as the above definition is met, there are several major pieces of hardware, including CPU, and the software that can run programs is a computer.
The single chip microcomputer is a kind of computer, and the characteristic of this kind of computer is "single chip".
What is monolithic? Is there a single piece and multiple pieces? It does.
The first one is a computer motherboard, and the second one is a single-chip microcomputer . Obviously, it can be seen that the computer motherboard is very complicated, and the single-chip computer is very simple.
If you have seen a computer motherboard, you know that the core of this thing is a PCB board with many chips soldered on it. Each chip is actually a "single chip", so the computer is a "multi-chip computer".
The microcontroller is a computer system with only one chip (essentially, there is only one semiconductor chip in the chip).
Then why are all computers, some have multiple chips, and some have single chips? In fact, it is still a matter of function size. The Tibetan mastiff grows so big and the pet dog grows so small, but they are all dogs, the same reason.
2. What is embedded
In fact, a single chip microcomputer is clearly defined, which is a computer system on a single chip. Although different MCUs have different configurations, different performances, different manufacturers, and even different instruction sets and development methods, they are all complete computer systems on one chip. This definition cannot be wrong.
Embedded is an unclear definition, and there is no clear definition of the word "embedded". He is not like a single-chip microcomputer, it is a certain "thing" name.
Embedded (embeded in English) is essentially an electronic design method. This method is to embed a microcomputer into an electronic product . As long as the electronic product conforms to this design method, it can be called an embedded system. This is a bit like the Hakka food stuffed (also written as Rang) bitter gourd stuffed tofu. When I first arrived in Guangdong, I only felt that the name of this thing was delicious. Later I realized that letting is actually a method of operation, which is to stuff the meat into bitter melon or In tofu, this design method of stuffing is called letting. So embedded system and let bitter gourd are actually a kind of naming technique.
Why is there this word? It is actually due to historical reasons. Because the early semiconductor technology was underdeveloped, computers were all big ones. So the electronic products at that time were all computers that came out independently, and then pulled a cord to control them in the electronic products.
Everyone, think about an air conditioner. The air conditioner is only for cooling, and there are no buttons on it. Then the air conditioner is pulled out and connected to a computer, and then press the keyboard to control the air conditioner through the computer. This type of air conditioner is called a non-embedded system.
In reality, the air conditioner you see is not like this. There are buttons on the air conditioner cabinet that you can press directly. Essentially, a circuit board is integrated inside the air conditioner. This circuit board is actually an embedded computer to control the air conditioner. Because the computer circuit board is "embedded" in the air conditioner, it is called an embedded system.
So you understand now that all the computer systems you see now, except for personal computers (in fact, there are dedicated computers such as servers, but they are rarely seen by everyone) are actually embedded systems . Including: home appliances such as air conditioners, refrigerators, washing machines, large items such as cars, trains and airplanes, smart phones and smart watches and other wearable smart hardware, cameras, smart door locks, self-service machines, etc., there are too many.
3. Is the microcontroller an embedded system?
Is the single-chip microcomputer embedded? Simply put: yes.
Because the computer system embedded in many embedded products is a single-chip microcomputer. For example, the control board embedded in an air conditioner is actually a single-chip microcomputer. In fact, most of the computer systems embedded in home appliances are microcontrollers.
Because the single-chip microcomputer is simple enough and cheap enough to use, it is the most cost-effective and most suitable to use the single-chip microcomputer. And now the largest field of single-chip shipments is home appliance products. Of course, there will be more and more IOT applications in the future, which will become a large incremental market for single-chips.
4. Broad and narrow embedded
The concept of embedded is actually very general. Nowadays, people who talk about the word embedded may have different meanings. The embedded concept we talked about above is the original definition of embedded, which is the so-called embedded in a broad sense.
Embedded in a narrow sense is actually short for "embedded linux system". Embedded in this narrow sense originally referred to an embedded computer system running a linux system. Later, it also included computers running other embedded systems at the same level as Linux (such as WinCE, Vxworks, Android, etc.).
This kind of embedded computer that can run linux is not a single-chip microcomputer. The single-chip microcomputer cannot run linux due to its limited resources and performance. Our usual products such as smart phones, car central control large screens, industrial control HMIs, network cameras, etc. are such narrowly-defined embedded systems.
So when you discuss with a person whether a single-chip microcomputer is an embedded device, you must first confirm with him what the embedded device is?
5 Conclusion
In a broad sense, single-chip microcomputers are embedded, but in a narrow sense, single-chip microcomputers are not embedded (linux).