Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, and toys. By reducing the size and cost compared to a design that uses a separate microprocessor, memory, and input/output devices, microcontrollers make it economical to digitally control even more devices and processes. Mixed signal microcontrollers are common, integrating analog components needed to control non-digital electronic systems.

About 55% of all CPUs sold in the world are 8-bit microcontrollers and microprocessors.

A typical home in a developed country is likely to have only four general-purpose microprocessors but around three dozen microcontrollers. A typical mid-range automobile has as many as 30 or more microcontrollers. They can also be found in many electrical device such as washing machines, microwave ovens, and telephones.

Atmel's low power, high performance AVR microcontrollers handle demanding 8- and 16-bit applications. With a single cycle instruction RISC CPU, innovative picoPower? technology, and a rich feature set, the AVR architecture ensures fast code execution combined with the lowest possible power consumption.

ARM is 32 bit Microprocessor helps in designing fast, low-cost, power-efficient peripherals and "system-chip" solutions for embedded control, consumer/educational multimedia, DSP and portable applications. ARM supports its processor offerings with development hardware and softwareand contract design services.ARM based technologies and services, which together satisfy a broad range of end user needs.ARM is rapidly becoming the global volume RISC standard.

ARM Core based Microprocessor is the industry's leading 32-bit embedded microprocessors, offering a wide range of processors based on a common architecture that deliver high performance, industry leading power efficiency and reduced system cost.

The need for the Migration arises because of:

1. Algorithms increasing in complexity. For example, the desire to make motors more power efficient pushes up the CPU performance requirements.

2. Consolidation of multiple subsystems into a single electronics board, to reduce system cost, footprint and power.

3. Platforms that were historically closed are starting to include wired and/or wireless connectivity. This puts further pressures on processor performance requirements and provides additional challenges to the system designer to ensure high degrees of system security/reliability and embed enough latent performance to support future services that maybe delivered across the network to deployed platforms.

The combination of these three factors will cause the 32-bit MCU market to grow at a rate that far outpaces the growth of other subsegments of the MCU market and indeed the market overall.

In these tough economic times, customers are looking to invest in one architecture and then leverage that investment as broadly across their portfolio of systems for as long into the future as possible. The diverse set of silicon devices, based on a standard MCU processor core enables OEM customers to select the device and vendor that best addresses their requirements, safe in the knowledge that they are not locked into a particular supplier.

ARM helps in designing fast, low-cost, power-efficient peripherals and "system-chip" solutions for embedded control, consumer/educational multimedia,DSP and portable applications. ARM supports its processor offerings with development hardware and software and contract design services.ARM based technologies and services, which together satisfy a broad range of end user needs.ARM is rapidly becoming the global volume RISC standard.

As the complexity of applications expands beyond simple tasks the benefits of an operating system far outweighs the associated costs. Since embedded systems are becoming more complex hardware-wise with every generation, and more features are put into them in each iteration, applications they run require more and more to run on actual operating system code in order to meet the system response requirements and to keep the development time reasonable.

Real-time computing is where system correctness not only depends on the correctness of logical result but also on the result delivery time. So the operating system should have features to support this critical requirement to render it to be termed a Real-time operating System (RTOS).

The RTOS should have predictable behavior to unpredictable external events. “A good RTOS is one that has a bounded (predictable) behavior under all system load scenario i.e. even under simultaneous interrupts and thread execution.”A true RTOS will be deterministic under all conditions.