On the one lesson wailing embedded technology, it is roughly Master of Magic.
Dian embedded technology is what a
teacher to the conclusion that: Portable Operating System, do application development on top of the operating system on existing hardware, do low-level development under the operating system. Honestly not too clear concept, only after listening to grab two points: Portable and operating systems.
So before we get back to the microcontroller to learn. SCM is the traditional development projects, connected directly between software and hardware, the disadvantage is about the degree of coupling between hardware and software is too high, poor portability adaptation platform that is poor, it can be said - single-mindedness. So the development of SCM requires that we have a deep understanding and mastery of software and hardware has, within the practice breath, playing outside horizontal steel body, energy consumption is more and more.
The embedded technology does, it is between the software and hardware built a bridge, the operating system. The role of the operating system, managers now responsible for managing the hardware and software resources. Or is the master key, no longer need to carry a special master key, take it to unlock. Then the operating system? It provides a wealth of network protocols, providing open source software and libraries, multi-tasking mechanism opens the door to intelligent era. Embedded operating system is a versatile system software, driver software typically includes a bottom-related hardware, system kernel, a device driver interfaces, communication protocols, a graphical interface, and the like standardized browser. It must be reflected in the system wherein it is possible to achieve the required functionality of the system by handling some of the modules.
Two Dian embedded development direction
1. The upper layer application software development (requirements: proficient in a language, a familiar operating system, grasp the corresponding data structure / algorithm). I think the popular understanding, is a software to do it 0.0. Now is not quite understand the specific situation, little introduction (below are the same).
2. The underlying system software development (requirements: proficient in C language, understand the implementation of the operating system, familiar with the hardware works, familiar with assembly). Why focus on the requirements proficient in C language? Dangdang Dangdang ~ as C language can access the hardware directly (there is a pointer can point directly in hardware address), portability and efficiency of the C language is also high, is really the world's best language ah!
3. embedded systems engineers. Mediterranean old, I should not want to go to understand.
Wed and embedded system composed
of an embedded system in general by means of embedded computer systems and actuators consisting, embedded computer system is the core of the embedded system, the hardware layer, an intermediate layer, a layer of system software and application software layer composition. Portable operating system for embedded systems, and portable way, or open source code provides portable interface. The hardware and software of real-time ... did not seem to take notes, only the title, there is a linux-free real-time.
Gone. . . .
No, the job: the type of the embedded cpu architecture, features and application scenarios.
1, embedded microprocessors
Embedded microprocessor word length is generally 16-bit or 32-bit, Intel, AMD, Motorola, ARM and other companies to provide many of these processors. Embedded microprocessors better versatility, strong processing power, scalability, addressing a large range, support a variety of flexible design, not limited to a specific field of application.
In practical application, embedded microprocessors need to configure the off-chip RAM and ROM, depending on the application requirements often extend some external interface device, such as a network interface, GPS, A / D interface. Embedded microprocessor and memory, buses, peripherals, etc. mounted on a circuit board, called a single-board computer.
Embedded microprocessor somewhat similar versatility in a general purpose processor, but the former function, price, power consumption, chip package Dian temperature adaptability, electromagnetic compatibility requirements more suitable for embedded system applications. There are many types of embedded processors, such as xScale, Geode, PowerPC, MIPS, ARM and other processors.
2, embedded microcontroller
Also known as embedded microcontroller MCU, this processor integrated RAM, a variety of non-volatile memory, a bus controller, timer / counters, watchdog, I / O, serial port, PWM outputs, A / D, D / A, and other necessary functions and peripherals.
As compared with an embedded microprocessor, microcontroller most important feature is the smallest computer system components required and some applications require a controller / external device integrated on a chip, a single chip, so that greatly reduce the chip size small, so that the total system power consumption and cost reduction, improved reliability. The on-chip microcontroller peripherals generally more abundant resources, suitable for the control, so called micro-controller. MCU variety, low prices, currently accounting for embedded systems more than about 70% market share.
3, embedded DSP
In the digital era of digital signal processing is a widely used technique, such as digital filtering, FFT, spectrum analysis, speech coding, video coding, data encoding, extraction, etc. radar target, during operation of a conventional microprocessor performing such calculations the lower performance, a dedicated digital signal processing chip --DSP also emerged, the DSP system architecture and instruction for a special design for digital signal processing, and therefore is highly efficient in performing the relevant operation. In applications, DSP always complete certain tasks, hardware and software needs to be customized for the application, and therefore is an embedded DSP processor.
4, the chip embedded system
In a class-specific application of embedded system performance, functionality, interfaces have similar requirements for the characteristics of embedded systems using LSI technology will most modules require a certain type of application integration in a single chip on, in order to achieve most of the core functions of an embedded system on a chip, this processor is the SOC.
The SOC commonly used microprocessors and application specific integrated modules on a chip, often only need to expand the memory external to the SOC, the application interface driver, a number of discrete components and the power supply circuit may constitute a practical system, greatly simplified difficulty of system design, as well as help to reduce the circuit board area, lower system cost, improve system reliability. SOC is an important development trend of embedded processors.
SOC embedded microcontroller and have the characteristics of high integration degree, all or most small computer system integrated in a single chip, some of the documents classified as an embedded microcontroller SOC. In order to follow more clearly described, the integration of internal RAM and ROM memory, a microprocessor controlled primarily referred to the microcontroller, and said SOC is not a built-in memory, embedded microprocessor core, integration of various It requires application of an external device controller, with a strong computing performance.
