What is the difference between embedded and microcontroller 2021?

Anyone who works in information technology related jobs must have heard of embedded and microcontroller.

We all know that these two terms, and hardware systems have a very close relationship. However, if you ask exactly what is embedded and what is microcontroller, and what is the difference between them, I believe most people can not explain clearly.

Today, Embedic will give you an introduction to science, to reveal the answer to the above question.

At the same time, Embedic also incidentally explain, we often say 51, STM32, what exactly is. What is embedded, first of all, let's see what is embedded. Embedded, generally refers to the embedded system, English called: embedded system. embedded development, in fact, is the development of embedded systems.

IEEE (Institute of Electrical and Electronics Engineers) definition of embedded systems is: "devices used to control, monitor, or assist in the operation of machines and equipment".

The domestic academic definition is a bit more specific and easier to understand.

Embedded system, is application-centric, based on computer technology, software and hardware can be cut, for special computer systems with strict requirements on functionality, reliability, cost, volume and power consumption.

Application-centric indicates that the embedded system is of clear practical use. Based on computer technology, it shows that it is actually a special kind of computer. Hardware and software can be cut, indicating that it has strong flexibility and customizability.

Special computer system, "special" corresponds to the "general". We often use personal PC, laptop, data center server, can be used for a variety of purposes, is the "general-purpose computer system".

What is the specific "dedicated" direction for embedded system?

The following are some examples.

Personal communication and entertainment systems: cell phones, digital cameras, music players, wearable electronics, PSP game consoles

Home appliances: digital TVs, floor sweepers, smart appliances

Office automation: printers, copiers, fax machines

Medical electronics products: biochemical analyzers, hematology analyzers, CT

Network communication products: communication type switching equipment, network equipment (switches, routers, network security)

Automotive electronics products: engine control, security systems, car navigation and entertainment systems

Industrial control products: industrial control machines, interactive terminals (POS, ATM), security monitoring, data acquisition and transmission, instrumentation

Military and aerospace products: UAVs, radars, combat robots

All of the above-mentioned fields use embedded systems. This is just the tip of the iceberg.

It can be said that the embedded system completely surrounds us and affects our work and life all the time.

Embedded system, since it is a computer system, it must be inseparable from the hardware and software.

A typical architecture of an embedded system is as follows: From the hardware point of view, the embedded system is a multi-module system with the processor (CPU) as the core and relying on the bus (Bus) for connection.

The middle upper left corner, S3C2440, is the CPU, the middle is RAM, and then there are ROM, network card, serial port, power supply, etc.. It can be seen that the embedded system is small, but all the guts. What is "microcontroller"? The core of the embedded system is the embedded processor. Embedded processors are generally divided into the following typical types.

Embedded microcontroller MCU (Micro Control Unit)

Embedded DSP processor (Digital Signal Processor)

DSP processors are dedicated to signal processing and are specially designed in the system structure and instruction algorithms. It is widely used in digital filtering, FFT, and spectrum analysis. Typical representative is the TMS320C2000/C5000 series from TI (Texas Instruments).

Embedded microprocessor MPU (Micro Processor Unit)

MPU evolved from general-purpose processors, with high performance and rich peripheral component interfaces. Typical representatives are AM186/88, 386EX, SC-400, PowerPC, MIPS, ARM series, etc.

In addition, there are embedded system-on-chip SoC (System on Chip) and programmable system-on-chip SoPC (System on a Programmable Chip). Our microcontroller belongs to the first of the above - MCU (embedded microcontroller).

Embedic to introduce it in detail.

Microcontroller, also known as Single-Chip Microcontroller, is called Single-Chip Microcomputer in English. It is actually an integrated circuit chip, which is a super large-scale integrated circuit technology, CPU, RAM, ROM, input/output and interrupt system, timer/counter and other functions, stuffed into a silicon chip, into a super small computer. In that case, the microcontroller is not an embedded system? Don't worry, let's read on.

The term "microcontroller" is actually an old name. Semiconductor technology is not mature, different functions can not be done into a chip (Chip), so there will be multi-chip machine. Now semiconductor technology has long been very advanced, so there is no multi-chip machine. However, the name "microcontroller" has been used until now.

Many college teachers like to emphasize the microcontroller surname "single", in addition to referring to the microcontroller is only a silicon chip, more refers to the single function of the microcontroller, it is to complete the computing, logic control, communication and other functions of a single module. Even if its performance is more powerful, the function is still single.

Microcontroller technology was born in the late 1970s, and in the early days it was 4-bit, and later developed into 8-bit, 16-bit, and 32-bit. It really rose to prominence in the 8-bit era. 8-bit microcontrollers are very powerful and are widely used in industrial control, instrumentation, home appliances, automobiles and other fields.

When we study microcontrollers, we often hear two words - 51 microcontrollers, STM32. let me introduce what they really are.

51 microcontroller, in fact, is the collective name of a series of microcontrollers. This series of microcontrollers, compatible with the Intel 8031 instruction system. Their originator, Intel (Intel) 8004 microcontroller.

Note that the 51 microcontrollers are not all products of Intel. Including ATMEL (Edmel), Philips (Philips), Huabang, Dallas (Dallas), Siemens (Siemens), STC (domestic macrochip) and other companies, there are also many products belong to the 51 microcontroller series.

The 51 microcontroller was once the most mainstream and widely used microcontroller on the market for a long time, occupying a large market share.

The 51 microcontroller actually has no technical advantage now and is a very old technology. The reason for its tenacity, in addition to its former popularity, is that Intel has completely opened up the copyright of the 51 core. Therefore, no matter any unit or individual, they can use 51 microcontroller without any fear of paying and without worrying about the risk of copyright.

In addition, the 51 microcontroller has a strong stock base and mass base. Many old projects are using the 51 microcontroller, for cost reasons, sometimes only continue to follow the 51 microcontroller technology to upgrade. Moreover, many of the older generation of engineers are proficient in 51 microcontroller development technology. Therefore, the vitality of the 51 microcontroller to continue.

Then look at the STM32.

STM32, is STMicroelectronics company launched based on the ARM Cortex-M core of general-purpose microcontroller.

STMicroelectronics, one of the world's largest semiconductor companies, was founded in June 1987 as a result of the merger of SGS Microelectronics of Italy and Thomson Semiconductor of France. Semiconductor Co.

ARM has been introduced to you before by Xiaozao Jun. It is currently one of the world's most powerful chip design companies, using the rapid development of cell phone chips and the rise of the Internet of Things market share is huge. In the field of microcontrollers, ARM's Cortex-M core has an overwhelming advantage and has become the absolute mainstream. Many semiconductor companies have abandoned their original architectures and switched to ARM architecture microcontrollers. STM32 hardware configuration can meet most of the IoT development needs, development tools and related documentation is complete, has become the current microcontroller learning object of choice.

The difference between embedded and microcontroller

Speaking of which, let's see, what is the difference between embedded and microcontroller.

From the previous introduction, embedded systems are a big category, and microcontroller is one of the important subcategories. Embedded system is like a complete computer, while microcontroller is more like a computer without peripherals. In the past, microcontrollers did not include much, and the hardware difference between the two was more obvious. However, with the rapid progress of semiconductor technology, now all kinds of hardware functions can be made into the microcontroller. Therefore, the hardware difference between embedded system and microcontroller is getting smaller and smaller, and the dividing line is getting blurred. Thus, people tend to make the distinction in software.

From the software, the industry often put the chip without MMU (memory management unit, memory management unit) and thus does not support virtual address, can only run bare or RTOS (real-time operating system, such as ucos, Huawei LiteOS, RT-Thread, freertos, etc.) system, called a microcontroller (such as STM32, NXP LPC series, NXP imxRT1052 series, etc.).

At the same time, the chip comes with MMU can support virtual address, can run Linux, Vxworks, WinCE, Android and other "advanced" operating system system, called embedded.

At some point, the microcontroller itself is powerful enough to be used as an embedded system. It is cheaper and relatively less difficult to develop and maintain, especially for some more targeted applications. Embedded systems, on the other hand, are theoretically more powerful and more widely used, but are more complex and difficult to develop.

The learning value of embedded and microcontroller

Finally, let's talk about the learning value of embedded and microcontroller, in the end there is no need to learn embedded and microcontroller.

In recent years, there is a phrase is widely spread, that is - "software is king". People generally believe that the value of software knowledge is much greater than hardware, and learning software, engaged in the direction of software, will be easier to find work, find higher income, more promising work.

Embedded and microcontroller, often classified as "hardware" direction, by people "dislike". In addition, embedded and microcontroller learning is more difficult, learning cycle is long, need a long "suffering", so more and more people give up this road.

Embedic think this idea is not correct.

First of all, embedded and microcontroller is not pure "hardware" class direction. As I said before, they are a close combination of software and hardware. If you want to learn embedded and microcontroller, only know digital circuit and microcomputer interface such hardware knowledge is not enough, you need to learn more, is assembly, C++/C++ language, data structure and algorithm knowledge.

Having the ability to combine hardware and software is far more valuable than simply mastering a certain program development language.

Secondly, embedded and microcontroller have a wide range of application scenarios, and there are project needs and talent demands in various fields. According to the authority statistics, the current annual shortage of embedded talents in China is as high as 500,000. Especially embedded software development is one of the hottest and most popular careers in the next few years. Senior embedded engineer with 10 years of experience can earn about 300,000-500,000 RMB per year. And our country is now vigorously developing chip industry, which will also drive the employment of embedded talents and improve the treatment. With the deepening of 5G construction, the whole society is developing in the direction of "Internet of Everything". IOT technology will also usher in unprecedented historical opportunities. Embedded and microcontroller technology is an important part of IoT technology, and will also enter the fast lane of development.

Therefore, although the learning process will be tough, Embedic still recommends aspiring young people to focus on this track. The harder the technology is, the more painful the process is, the better it is for building a competitive barrier. At a later stage, personal value can be further reflected.