ARM architecture

ARM is a family of instruction set architectures for computer processors based on a reduced instruction set computing (RISC) architecture developed by British company ARM Holdings. ARM Holdings develops the instruction set and architecture for ARM-based products, but does not manufacture products. The company periodically releases updates to its cores. Current cores from ARM Holdings support a 32-bit address space and 32-bit arithmetic; the ARMv8-A architecture, announced in October 2011,[6] adds support for a 64-bit address space and 64-bit arithmetic. Instructions for ARM Holdings' cores have 32-bit-wide fixed-length instructions, but later versions of the architecture also support a variable-length instruction set that provides both 32-bit and 16-bit-wide instructions for improved code density. History[edit] Microprocessor-based system on a chip The ARM1 second processor for the BBC Micro Acorn RISC Machine: ARM2[edit] The official Acorn RISC Machine project started in October 1983.

ARM9 ARM9 is an ARM architecture 32-bit RISC CPU family. Overview[edit] There are two subfamilies, implementing different ARM architecture versions. Differences from ARM7 cores[edit] Key improvements over ARM7 cores, enabled by spending more transistors, include:[1] Decreased heat production and lower overheating risk.Clock frequency improvements. Additionally, some ARM9 cores incorporate "Enhanced DSP" instructions, such as a multiply-accumulate, to support more efficient implementations of digital signal processing algorithms. Switching to a Harvard architecture entailed a non-unified cache, so that instruction fetches do not evict data (and vice versa). Cores[edit] ARM9TDMI[edit] ARM9TDMI is a successor to the popular ARM7TDMI core, and is also based on the ARMv4T architecture. ARM920T with 16 KB each of I/D cache and an MMUARM922T with 8 KB each of I/D cache and an MMUARM940T with cache and a Memory Protection Unit (MPU) ARM9E[edit] Chips[edit] Products[edit] Documentation[edit] See also[edit]

ASSP - a definition from WhatIs In computers, an ASSP (application-specific standard product) is a semiconductor device integrated circuit ( IC ) product that is dedicated to a specific application market and sold to more than one user (and thus, "standard"). The ASSP is marketed to multiple customers just as a general-purpose product is, but to a smaller number of customers since it is for a specific application. Like an ASIC (application-specific integrated circuit), the ASSP is for a special application, but it is sold to any number of companies. (An ASIC is designed and built to order for a specific company.) An ASSP generally offers the same performance characteristics and has the same die size as an ASIC. According to a Dataquest study, 17% of all semiconductor products sold in 1999 were ASSPs; 83% were general-purpose.

ARM11 ARM11 is a family of ARM architecture 32-bit RISC microprocessor cores. Overview[edit] The ARM11 microarchitecture (announced 29 April 2002) introduced the ARMv6 architectural additions which had been announced in October 2001. The ARM11 family are currently the only ARMv6-architecture cores. Differences from ARM9[edit] In terms of instruction set, the ARM11 builds on the preceding ARM9 generation. Microarchitecture improvements in ARM11 cores[2] include: JTAG debug support (for halting, stepping, breakpoints, and watchpoints) was simplified. ARM makes an effort to promote good Verilog coding styles and techniques. Cores[edit] There are four ARM11 cores: ARM1136[4]ARM1156, introduced Thumb2 instructionsARM1176, introduced security extensions[5]ARM11MPcore, introduced multicore support Chips[edit] Products[edit] Documentation[edit] The amount of documentation for all ARM chips is daunting, especially for newcomers. Documentation tree (top to bottom) See also[edit] References[edit] ARM Holdings Other

Software-Defined Radio Technology Promises Converged Wireless De Startup Kenet is working on military technology that, in civilian hands, could lead to wireless devices that can use hundreds or thousands of channels at very low power. New, low-power signal-processing technology being developed for the Navy may lead to multifunction wireless devices capable of communicating over a wide number of frequencies and protocols. In August, Kenet, a Woburn, Mass.-based fabless semiconductor company spun out of MIT, received a $1.3 million dollar subcontract to develop an advanced 12-bit analog-to-digital signal converter, or ADC, as part of defense contractor BAE Systems' work on software-defined radio for the U.S. A software-defined radio can send and receive any radio frequency protocol. Mike Ziehl, VP of marketing at Kenet, says that the ADC his company is developing will require 300 milliwatts, significantly less than a recently introduced competing chip that draws 2.3 watts. Kenet was founded in 2002, based on the license of seven patents. More Insights