ARM innovation gives 32-bit RISC performance at 16-bit system cost ================================================================== ARM re-defines RISC Rules to create Thumb ----------------------------------------- Cambridge, UK. March 6, 1995 -- Advanced RISC Machines Ltd (ARM) today announced a powerful extension to the ARM architecture - Thumb. This gives 16-bit system designers access to ARM's full 32-bit RISC architecture at 16-bit system costs without compromising performance. Because of a desire for more sophisticated features, many applications such as mobile phones, pagers and disk controllers now require more performance, address space and software support than 8 or 16-bit controllers can deliver. While 32-bit systems are fast enough, they may be too expensive for consumer markets, since they require more memory and a more complex circuit board. ARM re-applies RISC rules to reduce system cost ----------------------------------------------- By identifying the critical subset of the ARM instruction set and encoding it into 16-bits, ARM has succeeded in reducing typical program size by 30-40% from ARM's already excellent code density. Since this Thumb instruction set uses less memory for program storage, cost is further reduced. All Thumb aware processor cores combine the capability to execute both the 32-bit ARM and the 16-bit Thumb instruction sets. Careful design of the Thumb instructions allow them to be decompressed into full ARM instructions transparently during normal instruction decoding without any performance penalty. This differs from other 32-bit processors implementing a 16-bit data bus, which require two 16-bit memory accesses to execute every 32-bit instruction ('SX' style) and so halve performance. Performance is not compromised, flexibility increased ----------------------------------------------------- The patented Thumb decompressor has been carefully designed with only a small amount of circuitry additional to the existing instruction decoder, so chip size and thus cost do not significantly increase. Designers can easily interleave fast ARM instructions (for performance critical parts of a program) with compact Thumb code to save memory. Industry analyst James Turley, Senior Editor, Microprocessor Report said "For price-sensitive embedded applications, Thumb is a clever and unique solution. It keeps all the advantages of ARM's low-power 32-bit RISC architecture and adds the benefits of code density that 16-bit designers expect. Thumb's innovative approach doesn't sacrifice performance for low cost or low power, but gives embedded system designers an interesting new choice." Thumb is fully supported by the ARM Software Development Toolkit incorporating C compiler and assembler, profiler, instruction accurate simulator (ARMulator) and a Source Level debugger with graphical user interface (GUI). Third party tools vendors are also working closely with ARM to develop a range of software tools for Thumb. ARM offers Thumb benchmarking services through its consulting operation. ARM is working with its partners to produce Thumb-aware silicon, with the first public announcements coming from Cirrus Logic Inc and VLSI Technology Inc. Development card availability will coincide with the release of silicon in Q3/95. The first Thumb-aware core will be the ARM7TDMI macrocell (where the T indicates Thumb), which is destined initially for custom products in mobile communications and embedded control. ARM's Managing Director, Robin Saxby, comments that "The development of Thumb re-affirms ARM's leadership as the global volume RISC standard. Complementing last month's announcement of the high performance StrongARM partnership with Digital, Thumb allows ARM to serve control applications at significantly lower system costs than ever before. The ARM Architecture enables a broader range of applications than any competitive offering at best MIPS/Watt and MIPS/$ points." *** Ends *** Editorial Notes, Advanced RISC Machines Limited (ARM(TM)) --------------------------------------------------------- ARM designs, licenses and markets fast, low cost, low power consumption RISC processors for embedded control, consumer/educational multi-media, DSP and portable applications. ARM licenses its technology to semiconductor partner companies, who focus on manufacturing, applications and marketing. Each partner offers unique ARM related technologies and services, which together satisfy a wide range of application needs. ARM also designs and licenses peripherals, supporting software & hardware tools and offers design services, feasibility studies and training. ARM's global partnership is making the ARM architecture the world's volume RISC standard. ARM's partners are: VLSI Technology, GEC Plessey Semiconductors, Sharp, Texas Instruments, Cirrus Logic, Samsung, AKM and Digital Semiconductor. ARM's shareholders are Acorn Computers, Apple Computer, VLSI Technology and Nippon Investment & Finance (a Daiwa Securities subsidiary). Contacts: ARM Ltd - Trent Poltronetti Tel: +44 1223 400449, Fax: +44 1223 400410 e-mail: trent.poltronetti@armltd.co.uk Cirrus Logic Inc - Bo Ericsson Tel: 510 226-2069, Fax: 510 226-2240 VLSI Technology - Tom Schild Tel: 510 226-2069, Fax: 510 226-2240 ARM, Thumb, StrongARM and the ARM Powered logo are trademarks of Advanced RISC Machines Ltd.