Why use embedded software?

Question 1: What are embedded software and non-embedded software? Simply put, embedded software is application software or system software based on embedded platform (such as ARM+Linux); Non-embedded software mostly refers to software based on general-purpose processor and operating system platform (such as desktop application software).

Question 2: Why does the embedded system need an operating system? In the application of 8-bit or 16-bit embedded systems, because the amount of CPU resources is relatively small and the task is relatively simple, programmers can manage the CPU resources in the application without special system software. If the embedded system is complex and uses 32-bit CPU, the situation is completely different. The resources of 32-bit CPU are very large, and the processing ability is also very powerful. If the management program of CPU is still compiled by hand, it is difficult to give full play to the processing ability of 32-bit CPU in the face of complex applications, and the program is not reliable.

For example, the computer we usually use has abundant peripheral resources. If you don't use the operating system, you can use the development tool to start writing programs from the bottom, for a year or so, or maybe you can make the computer run and make a similar windows interface on the monitor. However, such a bare program can't make the PC play a powerful processing power at all. If you want to add an application function to the existing program, you must be familiar with the flow of other programs, and perhaps you should be familiar with the hardware knowledge and look at the hardware datasheet. If you want to transplant to another computer with different configuration, it is estimated that most programs will have to be reinvented!

From my current cognitive level, I think using the operating system on the embedded system has two advantages:

1. One of the strengths of the operating system is that it can make the application coding largely independent of the hardware and structure of the target board. So that programmers can focus as much as possible on the application itself, without having to care about the management of system resources.

2. Make the system development simple and shorten the development cycle. Make the application system more robust, efficient and reliable.

Of course, it is unnecessary to run the operating system for a very simple single-chip application. Although the operating system sounds good and powerful, it seems silly and naive to transplant everything up.

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PS:

There are many kinds of operating systems for embedded systems, and there are more than 51 operating systems, such as *** all_rtos, uCOS-II, and clinux, linux, wince and so on for higher-level applications! ~ ~ ~

Question 3: Is it necessary to have an operating system in an embedded software system and why? First of all, you have to understand what the operating system does.

An operating system is to let a cpu handle multiple different tasks.

Without an operating system, you can only handle one task. What should you do when handling other tasks?

1. Polling: When handling the main task, you constantly query whether you should handle other tasks. If so, you should handle other tasks. Immediately return to the main task after processing

2, foreground and background: when processing the main task, interrupts are set, which can be triggered according to external conditions, interrupt the main task, and then return to the main task after processing the interrupted task

. When there is an operating system, many tasks can be processed at the same time.

Why can only one cpu handle many things? The operating system divides the cpu's time. Perform a part of a task for a short time (this short time is very short, usually less than .2 seconds), and then switch to the next task, and keep cycling. Because the switching time is very short and the processing speed is very fast, it seems to people that many tasks are processed at the same time.

So whether to use the operating system depends on your application.

Question 4: Why do you want to learn embedded technology? The main reason for learning embedded technology is that the development prospect of embedded system is still good, which mainly includes the following points:

First, embedded software development can be described as the helm of software project development, and an excellent embedded software development should have strong logical thinking ability.

2. Although embedded software development requires comprehensive technology, it is not necessary to be paranoid about mastering all technologies. Any embedded software development has its own technical expertise and bias. For the technology in its own hands, embedded software development can be divided into proficiency-mastery-familiarity-understanding, which is divided according to the specific situation of work needs and career development.

third, because the all-round development of IT technology in all aspects of daily life has promoted the development of various software development directions, many embedded software developers enjoy both high status and salary.

Question 5: Which development direction is better, embedded system or software engineering? Don't be misled by my downstairs. "Embedded system is better than softworker." These are all P words. When it comes to money, even if you are skilled, you will be poor if you can't make money. Many people who don't know technology are on the rich list and have the same wealth. It is said that the difference between embedded and software engineering is dog P in terms of money, so most people in Microsoft are engaged in software. Let's see how many embedded senior workers outside can surpass these senior workers in Microsoft. You can't compare with others if you take the treatment of embedded senior workers in China. This is that different places, different directions and priorities have different treatments. If it is better for money, it is recommended not to choose technology, because it will kill a lot of time and even waste a lot of opportunities and time to make money. If you pursue technology, you should learn everything. If you don't learn it, it will be a loss. Even these are just small classifications, and there are more things worth doing.

question 6: which is better, embedded system or software engineering? At present, people in this field are scarce at home and abroad. On the one hand, IT is difficult for non-professional IT personnel to cut into this field because of the high entry threshold in this field, not only to understand the lower-level software (such as operating system level and driver level software), but also to have higher requirements on the professional level of software (embedded systems require higher time and space efficiency in software design) and to understand the working principle of hardware. On the other hand, because this field is relatively new and developing too fast at present, many software and hardware technologies (such as ARM processor, embedded operating system, MPEG technology, wireless communication protocol, etc.) have not appeared for a long time, and people who master these new technologies are certainly hard to find. Embedded talents are scarce, so their value is naturally high. The more experienced they are, the higher their price will be. In fact, embedded talents are scarce, and the fundamental reason may be that most people have unconditional contact, which requires corresponding embedded development boards and software, and experienced people to guide the development process.

in recent years, the embedded software industry has developed rapidly, and embedded products have penetrated into various industries, such as common mobile phones, PDA's, set-top boxes, high-definition televisions (HDTV), routers, automotive electronics, digital cameras, medical instruments, aerospace equipment and so on. Embedded development has become one of the hottest and most promising industries at present. The insiders believe that there is at least a talent gap of 3,-5, in the embedded industry, and the demand for embedded software developers in Chengdu alone has exceeded 4,-6,, of which the demand for embedded application software accounts for 8%, and it is still increasing. This is mainly due to two reasons: First, it is related to the professional setting of our universities at present, and computer education in Chinese universities rarely involves the development of embedded software, so it is difficult for enterprises to recruit practical talents who can immediately invest in embedded software development. Second, the threshold of embedded field is relatively high, the knowledge requirements are comprehensive, and a certain experimental environment (development board and tool software) and experienced people are needed for guidance. At present, in Beijing, the average monthly salary of a mature embedded software engineer is around 8, yuan. I want such a job opportunity. Embedded is really popular now, that is, in the current economic environment, such jobs are still in short supply, and enterprises cannot find suitable talents. The price is directly proportional to the value, so one of my classmates has gone to an embedded training course called Dongfang Saifu. I heard that the reputation in Beijing is the best. Now I have finished studying and found a 5.5K driver to develop the underlying driver, which is very enviable. . .

the embedded industry is divided into work types, embedded development, testing, technical support, business and so on. Technical support is the easiest. Development is the most tiring and stressful.

Question 7: Is it better to develop embedded software or hardware? Hardware is relatively rigid and fixed, but the design of software, especially system architecture, can exercise people's brains. Julian technology has always believed that doing software can better reflect the value of the human brain.

However, for work, especially for the development of embedded system, perhaps the best strategy

is to adhere to the philosophy of "completely fair scheduling (C

FS)" adopted in multi-task scheduling in linux kernel. Any process, as long as it needs cpu most, or has got the least cpu time < P > compared with other processes, the scheduler will give priority to scheduling cpu to him.

The same is true for learning software and hardware. Whenever you need to spend more time on something,

or you are not good at something, stick to it. In this way,

in the end, you will find that you have become an expert in embedded and even computer systems.

question 8: why does the development of embedded system need the comprehensive development of software and hardware?

For example, embedded system is equivalent to installing a computer by itself, and of course the system should be configured by itself.

question 9: what's the difference between embedded software development and software development? I happen to be embedded. Embedded system mainly deals with the combination of software and hardware, which is mainly based on C development on linux. It requires some knowledge of hardware, schematic diagram, common communication interfaces, I2C,SPI, etc. If something goes wrong, it needs to adjust the timing. When developing a product based on a certain chip, we should read the data sheet, understand the address mapping, address division, know the register function and define various functional interfaces. To transplant bootloader, kernel, make file system, write your own device driver, etc., assembly also needs to have a certain understanding. It is not easy to get started, but it is difficult to master.

question 1: what are the development trends of embedded software? 1. embedded development is a systematic project, so embedded system manufacturers are required to provide not only the embedded software and hardware system itself, but also powerful hardware development tools and software packages. At present, many manufacturers have fully considered this point, and at the same time, they have focused on promoting the development environment. For example, while promoting Arm7 and Arm9 chips, Samsung also provides development boards, versions and support packages (BSP), while WindowCE also provides Embedded VC++ as a development tool when pushing the system, as well as Tonado development environment of Vxworks and Limda compilation environment of DeltaOS, which are typical manifestations of this trend. Of course, this is also the result of market competition.

2. Requirements for networking and informatization With the maturity of Internet technology and the increasing bandwidth, the functions of previously single-function devices such as telephones, mobile phones, refrigerators and microwave ovens are no longer single, and their structures are more complicated. This requires chip designers to integrate more functions on the chip. In order to meet the upgrade of application functions, on the one hand, designers use more powerful embedded processors such as 32-bit and 64-bit RISC chips or signal processor DSP to enhance their processing capabilities, and at the same time, they add functional interfaces such as USB, expand bus types such as CAN BUS, strengthen the processing of multimedia and graphics, and gradually implement the concept of system on chip (SOC). In software, real-time multi-task programming technology and cross-development tool technology are used to control functional complexity, simplify application design, ensure software quality and shorten development cycle. For example, HP

3. Network interconnection has become an inevitable trend. In order to meet the requirements of network development, embedded devices in the future will inevitably require various network communication interfaces on the hardware. The traditional single-chip microcomputer has insufficient support for the network, while the new generation of embedded processors have begun to embed network interfaces. In addition to supporting TCP/IP protocol, some support one or more of IEEE1394, USB, CAN, Bluetooth or IrDA communication interfaces, and corresponding communication networking protocol software and physical layer driver software are also needed. In terms of software, the system kernel supports network modules, and even a Web browser can be embedded in the device, so as to truly access the Internet with various devices anytime and anywhere.

4. Simplify the system kernel and algorithm, and reduce power consumption and hardware and software costs. The embedded product in the future is a device with a close combination of software and hardware. In order to reduce power consumption and cost, designers need to simplify the system kernel as much as possible, keep only the software and hardware closely related to the system function, and realize the most appropriate function with the lowest resources, which requires designers to choose the best programming model and constantly improve algorithms to optimize compiler performance. Therefore, it is necessary for software personnel to have rich hardware knowledge and to develop advanced embedded software technologies, such as Java, Web and WAP.

5. Provide a friendly multimedia man-machine interface. Embedded devices can be in close contact with users, and the most important factor is that they can provide a very friendly user interface. Image interface and flexible control mode make people feel that embedded devices are like a familiar old friend. This requirement makes embedded software designers have to work hard on graphic interface and multimedia technology. Handwritten text input, voice dialing, sending and receiving e-mails, and color graphics and images will all make users feel free. At present, some advanced PDA have realized the writing of Chinese characters and the voice release of short messages on the display screen, but the general embedded devices still have a long way to go.

6. For enterprise-specific solutions, such as logistics management, bar code scanning and mobile information collection, this small handheld embedded system will play a huge role. In the field of automatic control, it can not only be used for special equipment such as ATM machines, vending machines and industrial control, but also be combined with mobile communication equipment, GPS and entertainment. Embedded systems can also play a huge role.

7. In the field of radio and television, the United States has begun to change from analog television to digital television, and DVB (Digital Television Broadcasting) technology in Europe has been popularized in most countries around the world. Digital audio broadcasting (DAB) has also entered the stage of commercial trial broadcasting. Software, integrated circuits and new components are playing an increasingly important role in industrial development. All the above products are inseparable from embedded system technology. Venus, whose future is immeasurable, plans to produce set-top boxes, and the core technology is to adopt 32.