White Paper Introduction to Intel® Architecture Introduction to Intel® Architecture The Basics Executive Summary The term Intel® architecture encompasses a combination of microprocessors and supporting hardware that creates the building blocks for a variety of computing systems. Although the architecture is straightforward and remarkably well-supported, the workings of these components may not be obvious to engineers, programmers, or product developers with no previous Intel architecture experience. This paper describes the basic operations and functions of the relevant components, using three example systems. Specifically, the paper will focus on the Intel® Core™ i7 processor (high-performance) and the Intel® Atom™ processor (low-power) implementations. In each case, the paper will walk the reader through the operation of the microprocessor’s communication with memory and peripheral I/O devices, the interaction between different types of components, and related design criteria. The goal of this paper is to The various system components are described along with the services they provide. describe the basic operation This paper will also define common terms used when describing Intel architecture designs and their operation. The final section highlights design aids, support, and and function of three classes of collateral provided by Intel and its partner provides to help create successful products. hardware platforms based on the Intel architecture and the components used. Jim Turley Principal Analyst, Silicon Insider White Paper Introduction to Intel® Architecture Table of Contents What is Intel® Architecture? experience. Software can be reused across generations of products, and product Intel® is the world’s oldest and most- What is Intel® Architecture? . 1 teams can protect their investment (in established microprocessor company, both hardware and software) in a cost- Introduction to Intel® Architecture . 1 producing the world’s most popular efficient manner. Although original work microprocessor chips. Although perhaps Basics of an Intel® Architecture may be required to take advantage of the best known for its PC processors, Intel System . 4 newest microprocessor features, the old devices are used in virtually every field Intel® Core™ i7 Processor–Based software will still work as-is. of electronics, including automotive, System . 5 industrial, automation, robotics, consumer Intel architecture chips have obviously The Intel® Core™ i7 Processor . 5 electronics, image processing, networking, undergone many changes over the past 40+ years. A list of currently available Intel’s Direct Media Interface encryption, military, construction, medical, 1 (DMI) . 6 energy, and other industries. devices is available here. Early chips were given technical part numbers, such Platform Controller Hub (PCH) . 6 Designers unfamiliar with the Intel as 8086, 80386, or 80486. This led to Intel® Atom™ Processor–Based architecture may have concerns about the commonly used shorthand of “x86 System . 9 the architecture’s fundamental concepts, architecture,” in reference to the last its inner workings, or its complexity. The two digits of each chip’s part number. The Intel® Atom™ Processor . 9 goal of this paper is to educate skilled Beginning in 1993, the “x86” naming Tools for New Designs . 9 developers with no previous exposure convention gave way to more memorable Conclusion . 10 to the Intel architecture and to provide (and pronounceable) product names guidance regarding system components such as Intel® Pentium® processor, Intel® References . 10 and concepts. Celeron® processor, Intel® Core™ processor, and Intel® Atom™ processor. Introduction to Intel® Architecture Although every branch of the broad Since the first tiny Intel 4004 Intel architecture (or x86) family tree microprocessor chip was made in 1971, retains the same basic features and Intel has produced an unbroken series functionality as the earlier chips, and of upgrades and improvements to the retains backward compatibility with them, world’s best known microprocessor family. each new generation also adds its own From its early 8-bit beginnings, the Intel unique features to the mix. For example, architecture now encompasses a range Intel Pentium processor added multimedia of 32-bit and 64-bit microprocessors extensions (called MMX™ technology) that that address a range of applications, accelerated audio and video processing. performance requirements, power levels, Extended temperature Intel Pentium and price points. processor with MMX technology is with The cornerstone of Intel architecture’s more streaming-media capabilities known popularity is its compatibility. Each as Intel® Streaming SIMD Extensions (Intel® new generation of Intel architecture SSE) and Intel® Streaming SIMD Extensions microprocessor is a superset of its 2 (Intel® SSE2). Floating-point units (FPUs) predecessors, providing backward went from optional upgrade to standard compatibility with older chips and older feature of Intel architecture processors, software, while also adding new or and today encryption/decryption enhanced features. This compatibility extensions, power-management features, allows engineers, programmers, and and multilevel caches are now found on development teams to reuse the most Intel architecture processors. Data software and software-development paths have widened from 8 bits to 32 tools from earlier projects, protecting bits, 64 bits, and even 128 bits and more. their investment in time and talent. It Operating frequencies have jumped from 1 http://ark.intel.com also makes developing new Intel-based a few megahertz to 2 GHz (two billion systems easier by leveraging developers’ cycles per second) and beyond. 2 White Paper Introduction to Intel® Architecture Some abbreviations used in the diagrams below: LPC Low Pin Count; a simple interface SATA Serial ATA; a popular to slower I/O devices disk-interface standard BIOS Basic Input/Output System; a boot ROM PCH Platform Controller Hub; SPI Serial Peripheral Interface; a companion chip simple interface to DDR3 Double Data-Rate v3; a popular slower devices DRAM interface standard PCI Peripheral Component Interconnect; a popular DMI Direct Memory Interface; a expansion bus video graphics standard PCIe* PCI Express*; an upgraded PCI FIVR Fully Integrated Voltage standard Regulator Figure 1: Typical system based on the Intel® Core™ i7 processor 3 White Paper Introduction to Intel® Architecture * Figure 2: Typical system with Intel® Atom™ processor (SoC) Similarly, many Intel® architecture chips ever more capable, there have been not stand alone, but works in concert now boast multicore performance, similar advances with the support logic, with compatible support chips. Different meaning that two or more Intel the development tools, and completely Intel architecture processors work with architecture processor cores, or “engines,” integrated hardware “platforms.” Every different support chips, and this paper operate within a single chip. Many also Intel architecture processor is supported outlines two representative examples. offer multithreading, a technique that by one or more chip sets that provide The first example describes a typical is designed to improve performance by needed system-level functions, and some hardware platform based on the allowing a single Intel architecture core to Intel architecture processors include their high-performance Intel® Core™ i7 processor perform multiple tasks. All the while, the own integrated functions such as memory combined with similarly high-performance power consumption and heat dissipation controllers, graphics engines, or network support logic (see Figure 1). The second of these processor chips has been kept interfaces. Sometimes the “chip set” is example focuses on a small, low-cost Intel in check thanks to aggressive on-chip internal, and the processor becomes a Atom processor–based system power-management hardware (some of standalone SoC – a system on a chip. (see Figure 2). which is adjustable through software) and industry-leading semiconductor- Basics of an Intel® Architecture Generally speaking, every Intel manufacturing technology. An in-depth System architecture hardware platform will description of the Intel architecture include two major components: the The hardware requirements for each technical features can be found in the microprocessor chip, and a companion customer application will be different, of Intel Software Developer’s Manual, chip known as the platform controller hub course, but some basics apply to all. The available here.2 (PCH). In earlier times, Intel® processors processor chip itself is just the beginning. were paired with two companion chips, And while the processors have gotten With few exceptions, the processor does often called the “north bridge” and 2 http://download.intel.com/design/processor/ manuals/253665.pdf 4 White Paper Introduction to Intel® Architecture the “south bridge,” or the MCH and the Intel® Core™ i7 Processor–Based The Intel Core i7 processor achieves its ICH. Nowadays, the functions of the System high performance through its multiple CPU north bridge are usually included in cores and its Simultaneous Multithreading the processor itself, while the south The example in Figure 1 illustrates a (SMT) feature. Between the four cores bridge has been replaced by the much high-performance system based on the (in this example) and the two-way more capable PCH. In single-chip (SoC) quad-core Intel Core i7 processor, the multithreading per core, the Intel