EMBEDDED SYSTEMS

Abstract:An embedded system is a combination of hardware and software along with necessary interfaces and connections to electromechanical components, sensors and actuators etc., for performing the desired function.
Sensors provide the interface between external environment and the embedded system. While maintaining the environment, sensors read input signals/data/. Data if analog is digitalized to make it usable for digital processing unit. This data is then processed and outputted in some specific format user(s) and may also generate and transmit commands for actuators for specific functionality.In our paper we also implemented the model of an automatic door opening system. All the requirement phase components are discussed in our paper which can be implemented and applied further through programming.

Applications:
Automotive – aircraft, automobiles etc.
Communication devices – Modems, cellular phones, embedded Internet, etc.
Consumer electronics – VCR, Pcs, PDAs, Micro oven, etc.,Industrial electronics – power plants, satellite control, anti – lock breaking system etc.,

INTRODUCTION

Embedded systems interact with the physical world to perform a single application or a small set of tasks e.g. control, protection and monitoring of processes, machinery, environment, and equipments. It is a combination of hardware and software along with necessary interfaces and connections to electromechanical components, sensors and actuators etc., for performing the desired function. Although an embedded system has some component, it is not itself a general-purpose computer. These systems are embedded usually in a larger system for some specific purpose other than to provide general purpose computing.

ORGANIZATION OF EMBEDDED SYSTEM

Embedded system are often developed with off-shell microprocessor/digital signal processor (DSP)/microcontrollers and ASICs/FPGAs for minimizing the cost and development time. In these systems the hardware, software and associated components are optimized for the given application or given set of tasks under the prevailing conditions keeping the size, cost and performance requirements in view.

A typical embedded system is a specialized computer system that has some sort of logical decision making capability and ability to interact with their task environment and the user in real time and an integral part of more intelligent and larger system.

Organization of an embedded system

Sensor provide the interface between external environments, sensors read input signals/data. Data if analog is digitized to make it usable for digital processing unit. This data is then processed and outputted in some specific format users and may also generate and transmit commands for actuators for specific functionality.


FUNCTIONS OF AN EMBEDDED SYSTEM
The function of embedded system can be broadly classified into two classes.

-> It monitors and controls the environment.
-> It makes necessary transformation and processing of information.


Categories:

In terms of their characteristics, the embedded systems may be placed under various categories as follows:
* DSP system.
* Reactive system.
* Distributive system and
* Consumer electronic system.

DESIGN ISSUES

The design process start with the system specification of the product which is derived from the assessment of requirements to be fulfilled by the system, performances with the various constraints relating to the environment of the embodying system, performance, cost and power consumption etc. the next step in design flow begins with the description of the functional architecture and the behaviors of the constituent components. The functional solution is then partitioned and allocated on to the hardware and software architecture that must specify the desired functionalities and system constraints of the application under consideration.. After the hardware and software components are synthesized, the next step in design flow is system simulation and validation. The validation is basically done to see that the system functionally correct and it meets the time requirements and other constraints. The validation is performed by a simulator, which allows all the heterogeneous parts of the system to be simulated together. After the completion of the validation phase, finally prototype of the design is brought up for actual testing and performance.

FUNCTIONS OF AN EMBEDDED SYSTEM

The function of embedded system can be broadly classified into two classes.

-> It monitors and controls the environment.
-> It makes necessary transformation and processing of information.




Categories

In terms of their characteristics, the embedded systems may be placed under various categories as follows:
* DSP system.
* Reactive system.
* Distributive system andConsumer electronic system.

DESIGN ISSUES

The design process start with the system specification of the product which is derived from the assessment of requirements to be fulfilled by the system, performances with the various constraints relating to the environment of the embodying system, performance, cost and power consumption etc. the next step in design flow begins with the description of the functional architecture and the behaviors of the constituent components.
The functional solution is then partitioned and allocated on to the hardware and software architecture that must specify the desired functionalities and system constraints of the application under consideration.. After the hardware and software components are synthesized, the next step in design flow is system simulation and validation. The validation is basically done to see that the system functionally correct and it meets the time requirements and other constraints. The validation is performed by a simulator, which allows all the heterogeneous parts of the system to be simulated together. After the completion of the validation phase, finally prototype of the design is brought up for actual testing and performance.

IMPLEMENTATION STRATEGIES

System On Chip (SOC):

An SOC in general consists of heterogeneous mixture of hardware and Software components where fixed small size program are being repeatedly executedby the processor , which is implemented from the IP core, provided by various Vendor. The high level integration from IP core, provided by various vendors.

The high level integration of millions of gates provided by advancement in Microelectronics has made ASCIs, FPGAs, and dedicated chips and generalized processors available in plenty. This advancement in the technology has led further to integrate microprocessor/micro controller / DSP, ASICs, FPGAs and memory components all on a single integrated circuit to constitute a system – on- chip. Some of the areas where we use SOCs are FAX, modems, laser printers and cellular phones.

Commercial – off- the shelf (COTS):

The availability of the low cost constituent components makes the COTs based approach cost effective and convenient. Due to its support for flexible reuse of hardware and software components it is suitable for quick modification of overall design to meet the desired specification. COTS based embedded systems can be implemented every often with simple incremented modification, which is an additional advantage over the customer implementation.

System On Chip (SOC)

An SOC in general consists of heterogeneous mixture of hardware and Software components where fixed small size program are being repeatedly executedby the processor , which is implemented from the IP core, provided by various Vendor. The high level integration from IP core, provided by various vendors.

The high level integration of millions of gates provided by advancement in Microelectronics has made ASCIs, FPGAs, and dedicated chips and generalized processors available in plenty. This advancement in the technology has led further to integrate microprocessor/micro controller / DSP, ASICs, FPGAs and memory components all on a single integrated circuit to constitute a system – on- chip. Some of the areas where we use SOCs are FAX, modems, laser printers and cellular phones.

Commercial – off- the shelf (COTS)

The availability of the low cost constituent components makes the COTs based approach cost effective and convenient. Due to its support for flexible reuse of hardware and software components it is suitable for quick modification of overall design to meet the desired specification. COTS based embedded systems can be implemented every often with simple incremented modification, which is an additional advantage over the customer implementation.

DISTRIBUTED EMBEDDED SYSTEM

Certain applications require the embedded components to remain physically distributed across the entire system. In such system distributed system comes up as an attractive choice where the embedded system functionalities are distributed among the constituents components including low cost microprocessor or microcontrollers or DSPs etc., which communicate among a shared medium.

In the distributed system heterogeneous buses connect different typesof processors in general where the designers of embedded system have many choices in connecting them as per requirement. For an embedded system with modest Communication requirements, connections orient protocols may be cost effective Solution.

CHARACTERISTICS OF AN EMBEDDED SYSTEM

An embedded system will have the following characteristics:

Physically distributed system.
Heterogeneous system.
Safety and reliability.
Cost sensitivity.
Weight.
Reactive nature.
Reaction with working environment.
Speed.

Automatic door opening system

APPLICATIONS
Automatic door opening system:

Automatic door opening system is one of the embedded applications, which consists of two sensors on either side of the door for sensing when a person enters. Sensors A on front side will sense when a person stands in front of the door and sends control to the motor to switch ON and wait for some delay time. Sensor B also performs the same operation as that of A but when the returns back from the room.
Sensor
Switch on the motor and wait for some time
If object detected ALGORITHM
Automatic door opening system:
*Initialize the ports of the 8051 microcontroller.
* If object is detected by the sensor,
-> Switch ON the motor
-> Wait for a delay
-> After delay, close the door by driving the motor in reverse direction.
*Else
-> Remain in the same state.
Indian scenario:
The global players are primarily focused on the back-end development work for the company’s offshore assignments. There are a significant number of global companies preferred outsourcing several activities in their value chain of which embedded system development assignment is one. India is preferred choice for outsourcing due to low development cost, availability of technically qualified and cheap man power especially in software segment.The total revenue generated is keep on increasing time to time in both domestic and international markets.

FUTURE OF EMBEDDED SYSTEM

The idea of printing a customized remote control for a color television any look far fetched, but the researchers at the university of California are already developing ink jet technology to print fully assembled electric and electronic gadgets at one go. When this technique is perfected, devices such as light bulbs, radios, remote controls, mobile phones and toys can be printed out as fully functional systems without expensive, labor intensive and Error-prone production on an assembly line. Embedded system is widely recognized as the future of computing.

The rapid increase in the use of embedded computers and communication technology has resulted in a large number of “ user hostile” systems. We have all seen VCRs which are difficult to program and flash 12.00 on their displays because they are so awkward to program. Successful implementation also requires that the designer have familiarity with hardware, software, and communication aspects of the system. There are significant opportunities for firms and individuals who can successfully implement “invisible” embedded system which are simple to use and reliable.

CONCLUSION

The popularity of embedded system is growing at very fast rate along with growing range of applications, advancement in hardware, software and other related technology. It is gaining further momentum with emergence of grand digital convergence arising out of convergence of appliances, platforms and technologies. Further scope of work remains wide open in design and implementations for Internet infrastructure, broadband and wireless network, consumer electronic products and smartcards apart from real time and online control systems.

Successful implementations also require that the designer have familiarity with the hardware, software, and communication aspects of the system. There are significant opportunities for firms and individuals who can successfully implement “ invisible” embedded systems which are simple to use and reliable.