Compact CPU core aims for cost-sensitive circuits

The ARM Cortex-M3 processor is specifically designed to meet the requirement for high system performance in extremely cost-sensitive embedded applications.

The ARM Cortex-M3 processor is specifically designed to meet the requirement for high system performance in extremely cost-sensitive embedded applications, such as microcontrollers, automotive body systems, white goods and networking devices.

This processor is the first member of the new ARM Cortex family of CPU cores, and underlines ARM's strategy of delivering technology around targeted market applications and performance requirements.

The ARM Cortex family enables chip manufacturers and OEMs to standardise around a single architecture from low-end microcontrollers to high-performance applications processors with Thumb-2 technology, significantly reducing development costs and increasing enterprise efficiency.

The ARM Cortex-M3 processor combines multiple breakthrough technologies that will enable chip vendors to deliver devices at extremely low costs, while achieving outstanding performance of up to 1.2DMIPS/MHz with a core of only 33,000 gates.

This design also integrates a number of tightly coupled system peripherals to achieve the exceptional system response needed to manage future generations of critical control tasks With the introduction of the ARM Cortex-M3 processor ARM is for the first time specifically targeting the very low-cost requirements of a broad range of markets and applications, including microcontroller and automotive segments, where memory and core size significantly impact device costs.

This microcontroller market, currently worth approximately $2.5 billion, is traditionally serviced by legacy 8 and 16bit devices, but it has seen a substantial growth in performance requirements as users demand greater flexibility, and as cost demands force the consolidation of multiple applications onto a single device.

The ARM Cortex-M3 processor, with multiple technologies to reduce memory use while delivering industry-leading power and performance in a notably small RISC core, delivers an ideal platform to accelerate the migration of thousands of applications around the globe from legacy components to 32bit microcontrollers.

"The 32bit microcontroller industry blossomed in the last 5 years, quadrupling in revenues to reach $2.4 billion in 2003".

"Over the next five years, the market will double in size again", said Tom Starnes, Research Vice President, Gartner.

In addition to substantially reduced memory requirements the ARM Cortex-M3 processor also delivers many other cost savings to ARM silicon partners and the ultimate end users.

With the lowest gate count of any ARM CPU, the ARM Cortex-M3 processor takes up substantially less silicon area than previous designs, enabling a physically smaller device, or the use of lower cost process technology.

Additionally, the close integration of essential system peripherals ensures optimal silicon space utilisation.

The ARM Cortex-M3 processor also introduces a new standard debug technology based on a single wire, which can eradicate the multipin overhead associated with JTAG debug, an important saving in cost-sensitive applications.

"The ARM Cortex-M3 processor significantly extends the reach of the ARM architecture, and advances our goal of providing processor solutions for the entire digital world", said Mike Inglis, EVP Marketing, ARM.

"By providing our Partners with a design that delivers high performance at low cost, we are enabling them to accelerate the delivery of highly competitive 32bit products into the volume automotive and microcontroller markets, and speed the migration from legacy technology".

"Accelerated Technology welcomes the introduction of the ARM Cortex-M3 processor as it enables a much wider group of developers to migrate to a 32bit platform for developing real-time applications", said Robert Day, Marketing Director for Accelerated Technology, the Embedded Systems Division of Mentor Graphics.

"The combination of the Nucleus RTOS and its associated middleware with the Cortex-M3 processor will provide the most complete solution with the best performance for developers entering the 32bit world".

"The ARM Cortex-M3 processor with its high system performance, exceptional interrupt handling and low-cost architecture, is an ideal platform on which to develop deeply embedded real-time applications", said William E Lamie, President of Express Logic.

"To help developers take advantage of these outstanding capabilities, Express Logic has committed to porting our popular real-time operation system (RTOS) ThreadX, our NetX TCP/IP stack, and our FileX file system to the Cortex-M3 processor in time for its general release".

The ARM Cortex-M3 processor tightly integrates an efficient 32bit Harvard microarchitecture executing Thumb-2 instruction with other close system peripherals, including a nested vectored interrupt controller and a bus arbiter.

This solution delivers outstanding performance in benchmarks and real-world applications, delivering 1.2DMIPS/MHz at clock frequencies up to 100MHz on a TMSC 180nm process.

The ARM Cortex-M3 also implements interrupt tail-chaining technology, a fully hardware-based interrupt handling mechanism which reduces interrupts overhead to a maximum of 12 clock cycles, a reduction of as much as 70% in real-world applications.

The ARM Cortex-M3 processor additionally delivers a performance increase of 60 percent, a size reduction of 33%, and a power consumption reduction of 75% over comparable processors.

Full tools support for the ARM Cortex-M3 processor, including RealView compiler and RealView debug products, is being developed in parallel to the core to take full advantage of the many debug architectural improvements, such a the single wire debug and improved system visibility.

ARM CEO, Warren East, has also outlined the company's strategy to extend its processor range and continue to deliver architectural innovation.

The introduction of the ARM Cortex family of processors will provide partners with solutions optimised around specific market applications across the performance spectrum.

The three series within the ARM Cortex family all implement the Thumb-2 instruction set to address the increasing demands of various markets.

The three categories are as follows: ARM Cortex-A Series of applications processors for complex OS and user applications; ARM Cortex-R Series of embedded processors for real-time systems; and the ARM Cortex-M Series of deeply embedded processors optimised for microcontroller and low-cost applications.

"Our silicon Partners are looking for strong architectural innovations across the whole of the digital performance spectrum to drive down device costs while delivering higher performance in practically every application", said John Cornish, Director of Product Marketing, ARM.

"The new Cortex family strategy enables us to deliver cores that are highly targeted at specific application requirements, such as the microcontroller market, where the new ARM Cortex-M3 technology delivers outstanding 32bit performance in a cost sensitive package".

"This enables our partners to deliver extremely competitive devices".

Based on a next-generation version of the ARM architecture, the ARM Cortex family integrates Thumb-2 technology which combines both 16 and 32bit instructions to deliver the best balance of code density and performance.

Thumb-2 technology uses 26% less memory than pure 32bit code to reduce system cost, while at the same time delivers 25% better performance than 16bit code alone enabling designers to save power by reducing clock speed.

The ARM Cortex-M3 processor is available to license now with optional Embedded Trace Macrocell (ETM) technology.

Completed deliverables including models, compatible RealView development tools, and synthesisable RTL will be released to ARM partners by Q3 2005.

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