The giant of Cambridgeshire (Part 3) - Architecture development & A semiconductor IP supplier

4/12/2012 9:01:08 AM

Architecture development

Description: Architecture development

Because today’s ARM processors and cores (we’ll differentiate between these two terms later) are direct descendents of the original ARM chip that was designed for Acorn’s Archimedes back in 1987, they are referred to as ARM architecture devices. This is similar to today’s Intel and AMD chips, which grew out of the Intel 8086 and its successors, and are therefore described as adhering to the x86 architecture. Here we’ll look at what was unique about the ARM architecture when it appeared 25 years ago, how it has evolved over the years, why that evolution hasn’t paralleled that of the 86 architecture, and what remains distinctive about it today.

Those who have followed the development of the PC over the years will no doubt he familiar with the concept of processor generations within the x86 architecture. In recent years the dividing lines have become somewhat less distinct, but in the early days we saw the first generation 8086 (or 8088) give way to the 80286 and subsequently to the 80386, 80486, the Pentium and so on. The same is true of the ARM architecture, but with one important difference. In the realm of x86, new generations have, on a couple of occasions, been associated with the introduction of a new headline figure for the width of the data pathways — something that has a significant impact on performance.  So the x86 architecture lunched with the 16-bit 8086, and subsequent developments have brought us 32 bits and eventually the 64-bit architecture we enjoy today. In total contrast to this, the ARM architecture made its debut at 32 bits and has yet to make the transition to 64 bits. However, that shouldn’t be interpreted as a lack of innovation, as a few facts and figures vi1l reveal.

The first ARM processor saw the light of day in 1985, and while it was never used commercially, the ARM 2 that followed it, and which powered the first Archimedes PC, wasn’t too dissimilar. Although it was based on a 32-bit architecture, it had a 26-bit address bus, which meant that it could address 64MB of memory. Although not a lot by today’s standards, this was a huge amount in the mid-’80s. The clock frequency of 8MHz also sounds rather pedestrian although, as a result of the RISC design, it was able to provide a speed of 4 MIPS (million instructions per second). To put this into context, the Intel 80386, which appeared on the scene a year later, was just a touch faster at 5 MIPS, but to achieve this it had to be clocked at 16MHz. However, to see the advances the ARM architecture has enjoyed in a quarter century of development, we really need to draw some comparisons with today’s offerings.

In terms of raw performance, today’s top-end core is the Cortex-A15, which is based on the seventh generation architecture, known as ARMv7. Although the clock speed depends on the manufacturer (ARM Holdings itself doesn’t manufacture any silicon), a figure of 2.5GHz is considered a likely ceiling, and at this speed it would clock up a performance of around 35,000 MIPS. While this comes nowhere near the latest Intel Core i7, we’re not comparing like with like. When expressed in terms of MIPS per core per MHz, although it still doesn’t overtake the core i7, the Cortex-A15 comes much closer — but even this is missing the point. Indications are that the Cortex-A15 will consume less than a watt per core compared to tens of watts per core for the Core 17. In this respect it comes closer to the Intel Atom, but with much greater performance.


Spotlight on the Archimedes

How the BBC Micro’s successor changed the face of computing

The Archimedes was never as well known as its hugely successful predecessor, the BBC Micro. Yet without it, the ARM architecture would probably never have come into being and today’s smartphones and tablets might boast Intel rather than ARM technology. So what was so special about this personal computer that it changed the face of the micro electronics industry?

At first sight, the specification doesn’t sound particularly special. The entry- level model 305 had an 8MHz processor, 512KB of memory and a single floppy disk drive (a hard disk was an optional extra), and it cost $1438.4. However, in comparison to most home computers of the day, which were little more than toys, cassette tape data storage and all, the Archimedes was much closer we’d think of as a proper PC. Of course the IBM PC and the Apple Mac were already available, and while these were undoubtedly serious computers, they had price tags that, back in 1987, meant that they were first and foremost business tools and rarely found their way into the home. What made the Archimedes stand out from anything else at the time with a similar price tag was its graphics. With a resolution of 640 x 256 (or 640 x 512 with the optional high resolution monitor) in 256 colours, the Archimedes stood head and shoulders above the competition. Even the IBM PC could only boast 640 x 200 pixels in monochrome or 320 x 200 in four colours. And while Windows wouldn’t become popular on the PC for another five years with the launch of Windows 3.0, at the outset the Archimedes could boast a graphical user interface. This brings us back to that innovative 32-bit RISC ARM chip, without which the Archimedes’ high resolution graphics and GUI just wouldn’t have been feasible.

Description:               The Acorn Archimedes was ground breaking, due In no small part to the ARM processor inside

              The Acorn Archimedes was ground breaking, due In no small part to the ARM processor inside


A semiconductor IP supplier


Description: Devices like tablets benefit from ARM’s low-power RISC designs

Devices like tablets benefit from ARM’s low-power RISC designs


The world’s first semiconductor companies designed and manufactured chips. Intel still adheres to this model, manufacturing its processors at Intel-owned fabs (industry jargon for fabrication plants, mainly in Arizona and Oregon. Although AMD originally worked in the same way it is now a fabless semiconductor company. This means that, although it designs and markets microprocessors, it subcontracts the manufacturing to a so-called silicon foundry ARM Holdings is even further removed from real-world products since, although it designs processors, it neither manufactures silicon chips nor markets ARM-branded hardware. Instead it sells, or more accurately licences, intellectual property (IP), which allows other semiconductor companies to manufacture ARM-based hardware. These chips might be microprocessors as we understand the word, but alternatively they could be complicated chips that form the basis of a mobile phone, for example, of which the ability to execute software is just one element.

So in buying the rights to manufacture an ARM- based product, exactly what does a semiconductor manufacturer receive? We put this question to Ed Plowman, technical marketing manager at ARM’s Media Processing Division. “Originally the predominant mode of delivery was via hard macros,” he told us. “This is a definition the chip’s layout — what to deposit where, and how to connect it all together to make a working circuit”. Over time though, as the number of transistors in the chips increased, along with the number of processes by which each could be manufactured, this became impractical. Designs arc now mainly supplied as a circuit description, from which the manufacturer creates a physical design to meet the needs of its own manufacturing processes. But this data isn’t supplied as a circuit diagram — it’s provided in a hardware description language that provides a textual definition of how the building blocks connect together. The language used is RTL (register transfer-level), which means, as Ed says, “the definition isn’t at the transistor level, but defines how data flows between registers”. This isn’t an area where one size fits all, though. ARM sometimes still chooses to implement a hard macro to improve time to market and optimised solutions for certain high-volume process technology nodes. This is the way, for example, that the Osprey (dual-Cortex-A9) is delivered so pretty much all the manufacturer has to do is create the masks.

  •  UK tech skills crisis
  •  Graham Barlow: the Apple view
  •  Graham Morrison: The advocate
  •  Cars 2.0 : Hacking by hi-fi & Playing catch-up
  •  Automated cities : App development & Urban OS in the UK
  •  Searching for Google’s future (Part4) - Smarter search
  •  Searching for Google’s future (Part 3) - Gene genie
  •  Searching for Google’s future (Part 2) - Playing a long game & Mobile money
  •  Searching for Google’s future (Part 1) - Taking the tablets
  •  Small Business Development Centers - Assistance For Entrepreneurs
  •  How to set up your own virtual private network (Part 2)
  •  How to set up your own virtual private network (Part 1)
  •  LCD NEC EX201W
  •  Collaborating via Web-Based Communication Tools : Evaluating Web Conferencing Tools
  •  Visual Studio 2010 : Writing Custom Facebook Applications - Querying Data from Facebook
  •  Writing Custom Facebook Applications - Creating Your Application with Visual Studio 2010
  •  Xen Virtualization : Installing Xen from Source
  •  Xen Virtualization : Installing Xen from Binary Packages
  •  Introducing IBM BPM and ESB : IBM SOA Reference Architecture & Introducing IBM WebSphere Process Server
    Top 10
    Windows Vista : Installing and Running Applications - Launching Applications
    Windows Vista : Installing and Running Applications - Applications and the Registry, Understanding Application Compatibility
    Windows Vista : Installing and Running Applications - Practicing Safe Setups
    Windows Server 2003 : Domain Name System - Command-Line Utilities
    Microsoft .NET : Design Principles and Patterns - From Principles to Patterns (part 2)
    Microsoft .NET : Design Principles and Patterns - From Principles to Patterns (part 1)
    Brother MFC-J4510DW - An Innovative All-In-One A3 Printer
    Computer Planet I7 Extreme Gaming PC
    All We Need To Know About Green Computing (Part 4)
    All We Need To Know About Green Computing (Part 3)
    Most View
    iPhone 3D Programming : Blending and Augmented Reality - Shifting Texture Color with Per-Vertex Color
    How To Automate Your Web With ifttt (Part 2)
    Top Tips For Mountain Lion (Part 3)
    Windows Server 2008 R2 monitoring and troubleshooting : Performance Monitoring
    Buyer's Guide: 3D Monitors (Part 3) - BenQ XL2420T, Samsung SyncMaster S23A750D, Asus VG278H
    Windows Vista : Scripting and Automation - Object References (part 3) - How to Manage Windows Services, How to Write CGI Scripts for Web Servers
    Essential Wedding Kit (Part 3) - Shoot-saving kit
    Active Directory Domain Services 2008 : Add a User, Group, or Computer to the Password Replication Policy
    Apple Extends An Olive Branch In The Dying Days Of MobileMe
    Windows Vista : The Wired Ethernet Network - Connect the Hardware
    Communicate Between Two Machines on the Same Network (WCF)
    Group Test: Which Are The Best Cases On The Market? (Part 1) - Corsair Graphite 600T Steel Silver Case, Xigmatek Elysium Windowed Case
    Windows 7 : Zero Touch Installations - Understanding Configuration Manager
    Microsoft XNA Game Studio 3.0 : Working with Colors
    How To Put Together A Good Home Network (Part 4)
    Sansui CDD-201V – New Budget CD Player
    Introducing IBM WebSphere Enterprise Service Bus (WESB)
    Retro - Cloud Computing
    Asus PB278Q – A Monitor With Excellent Resolution
    The Linux Build: Part For Penguins (Part 4)