What is an embedded system?

What is an embedded system-general Linux technology-Linux programming and kernel information, the following is a detailed description. Generally, an embedded system is a device or system that "executes special functions and is controlled by an internal computer. Embedded Systems cannot use general-purpose computers and run solid software. The term is firmware. it is difficult or impossible for end users to change the firmware ."

People with technical concepts should be able to understand the above definition, but there may be some obstacles for non-technical people. A simpler definition is: "an embedded system is a device that contains computers that you do not know ."

However, some explanations are required for this definition. First, most non-IT people refer to computers as a beige box labeled "Intel-Inside. The circulation of embedded computers is much higher than that of Intel-x86/Pentium-based hybrid PCs. Intel may be "inside", but embedded systems are everywhere.

People seldom realize that they often carry several embedded systems with them-mobile phones, watches, or smart cards, and they are often unaware of interacting with embedded systems of cars, elevators, kitchen equipment, televisions, video recorders, and entertainment systems. Embedded systems play a more important role in Industrial Robotics, medical devices, telephone systems, satellites, flight systems, and other fields. The "invisible" feature distinguishes embedded computers from general PC computers.

Embedded Architecture

As a technician, you may want to define an embedded system from the system perspective. Although most embedded systems are customized for specific tasks, they are generally composed of the following modules:

A computer or microcontroller may have four or eight, 16, 32, or even 64 characters in length.

ROM used to save the firmware (non-volatile read-only memory ).

RAM used to store program data (volatile random access memory ).

Connects the I/O Ports of the microcontroller and switch, button, sensor, analog-to-analog converter, controller, LED (Light Emitting Diode), and display.

A lightweight embedded operating system is generally self-compiled.

Dedicated single-chip microcontroller is the core of most embedded systems. By integrating several key system components into a single chip, system designers can get computers that are small, cheap, and can operate fewer peripheral electronic devices.

The general model of an embedded system is not enough to define the embedded system itself. For example, some embedded systems are usually not much smaller than standard PC chassis. Such devices include:

Information Query and point of sale terminal.

Some industrial control systems.

Game console (for example, Xbox Based on x86 and Windows ).

Digital recorders (such as Linux-based TiVo ).

These devices may use hard drives to save firmware and run various desktop operating systems, such as Windows, Linux, or DOS. This is not a typical embedded system architecture, but according to my earlier definition, they can still be called embedded systems.