Embedded systems are contained in just about every electrical item in existence, and unless they break down most people are unaware of their presence. Embedded computer systems differ from general systems in that they are designed to perform a single task and are only ever intended for one specific purpose. They can be utilised for the most basic of tasks such as a 4-bit processor in a digital watch, or they can be used for the advancement of mankind as a component in a complex system such as the Mars Rover. When designing an embedded system there are seven requirements which must be considered by the user, and this article examines each one in detail.
Processing Power
Most embedded systems are built with 4-, 8-, and 16-bit processors, and you will have to decide which one is most suitable for the task you wish to perform. The standard way to compare processing power is by millions of instructions per second (MIPS), and a higher rating indicates a more powerful processor.
Memory
The amount of memory required to run your software will also have an effect on which processor you choose. A 16-bit processor can support a maximum of 65KB of RAM, whereas an 8-bit processor can address only 256 bytes.
Number of Units
How many units you require for your system will depend on the task you wish to accomplish. Your network may consist of a just one single board computer or hundreds of different components. You will also need to take into account the amount of space you have available, your budget and amount of RAM needed to run your software.
Power Consumption
Power consumption is extremely important when it comes to portable devices, and the standard measurement system for power consumption is milliwatts per MIPS (mW/MIPS). Devices that require less power are usually smaller, simpler and generate less heat.
Development Cost
This applies mainly to the manufacturer but also affects the consumer as a high development cost will result in a more expensive end product. The cost of developing hardware and software can be extremely high, but it is usually a one-time cost and is known as a ‘nonrecurring design engineering’ (NRE) charge.
Lifetime
How long does the system have to last before it has to be replaced? If you plan on upgrading your system regularly, then longevity may not be a factor in your decision, but if you only plan on purchasing your hardware once you will need to find a system that will stand the test of time.
Reliability
How reliable your system needs to be will depend on the duty it has to perform. Embedded systems in anti-lock brakes must work 100% of the time, but a system for an electrical gadget used for entertainment purposes may not have to be so reliable.
Designing an embedded system can be a complicated process, but as long as you satisfy all the predicted requirements in the planning stages your finished system will function without any issues whatsoever. Once set up, embedded systems will perform their task without the need for much prompting, so it is worthwhile investing a good deal of time in choosing the right components for the job.
Author Bio: Lewis Brooks is a business systems technology consultant. He enjoys blogging about business applications and trends.