Cortex-R4: New ARM Processor

ARM announced the new Cortex-R4 processor, targeted at mobile phones, hard-disk drives, printers and automotive designs. The Cortex-R4 processor enables configurability during synthesis to optimize the processor for different embedded applications through the memory protection unit, caches and tightly coupled memory (TCM). It does this without compromising the underlying ARM instruction set compatibility, maximizing the reuse of existing software investments by application developers and third parties.

For 3G smartphone designs, the boost in performance from the Thumb-2 instruction set allows the Cortex-R4 processor to be used in place of the two separate processors that traditionally would be used in 3G baseband modems. This saves cost and complexity while still running all of the same code.

For automotive applications, the Cortex-R4 processor includes fault tolerance for critical safety applications as well as memory protection that supports the latest version of the OSEK real-time operating system. This is important for building system-on-chip (SoC) devices for engine-management systems that have to run in real time with a wide range of peripherals.

The Cortex-R4 processor features an advanced microarchitecture with dual instruction issue capability to deliver more than 600 Dhrystone MIPS in a performance-optimized 90nm implementation, based upon the ARM Artisan Advantage library. The processor also provides key savings in cost and power consumption for system developers, occupying less than 1mm² and consuming less than 0.27mW/MHz in an area-optimized 90nm implementation.

ARM has already secured three lead licensees for the Cortex-R4 including Broadcom, and the processor has received support from major EDA, RTOS and tools vendors.

ARM has developed a full range of supporting technology around the new processor to reduce design time. This complete system solution includes development and debug tools, modeling technology and physical cell libraries. The Cortex-R4 processor is supported by the ARM RealView DEVELOP family of software development tools, the RealView CREATE family of ESL tools and models, and CoreSight debug and trace technology for developing embedded systems quickly.

The AMBA Designer design automation tool provides a design flow for advanced AMBA interconnect sub-systems, further reducing implementation costs and time to market. Additionally, the AMBA 3 AXI protocol-compliant ARM PrimeCell peripherals, including the AMBA 3 AXI Interconnect (PL301), Configurable Dynamic Memory Controller (PL340), Static Memory Controller Family (PL350) and L2 Cache (L220), further improve the performance of the processor.

The Cortex-R4 processor runs the ARMv7 ISA, making it fully backward compatible with existing ARM code that powers billions of systems around the world, and is optimized for the Thumb-2 instruction set. This allows numerous benefits including lower clock speed that brings power-saving advantages, higher performance which offers feature-rich additions to mobile phones and automotive designs, and more complex algorithms for high-performance digital imaging and hard-disk drive systems.

Using the Thumb-2 instruction set, together with the ARM RealView Development Suite, allows on-chip memory sizes to be reduced by up to 30 percent, saving significant cost in the system. In addition, it can produce a 40-percent performance improvement over the previous Thumb instruction set running on an ARM946E-S processor. As memory is an increasingly large proportion of a chip, this provides a significant saving in area and cost to chip makers using the processor for SoC devices.