MEDIA PROCESSORS

The Best Solution for Implementing Multimedia in the PC Environment

Multimedia, only recently a buzzword without much practical application, is about to come of age thanks to the media processor, a new class of semiconductor device that is making high-quality multimedia on a mass scale economically feasible for the first time. Using media processors, manufacturers of a wide range of products -- from personal computers to ATMs to automobiles to "smart" digital video disk players -- are finding new ways of conveying information between people and machines.

The media processor can be defined as a computational engine specifically designed to efficiently manipulate natural data types -- audio, video and graphics data -- that can be programmed like a computer to perform virtually any combination of multimedia functions simultaneously. The media processor is the heart of what will become a standard component of many consumer and commercial products -- the multimedia subsystem -- providing all the multimedia functionality required economically without sacrificing quality. In fact, the media processor will make possible many advanced multimedia functions that would be too costly to implement in using traditional approaches.

The huge performance and cost efficiencies made possible by the media processor's unique approach is making multimedia extremely attractive for wide range of commercial and consumer electronics products. Manufacturers are also attracted by the media processor's flexibility, which enables them to create a family of products with a range of multimedia capabilities using a single device and keep up with changing features and standards through simple software upgrades.

Several factors have converged to make the media processor practical. First, the availability of 0.50 and 0.35 micron semiconductor fabrication facilities enables the required number of devices to fit on a die small enough to be economically feasible. At the same time, the huge volumes required, because the media processor can be used in so many applications -- will also drive costs down significantly. Second, the recent appearance of low-cost, high-bandwidth memories enable the media processor to "breathe" while keeping costs down. Third, Microsoft's introduction of Direct-X APIs removed the barrier to widespread acceptance of multimedia in the PC market, perhaps the first where the media processor will appear, by enabling applications to access multimedia functionality in a standardized way, regardless of the underlying hardware implementation.

The broad applicability of media processors is reflected by the first-generation devices being announced by a number of mainstream semiconductor manufacturers, including IBM, Toshiba, NEC, LG Semicon and Philips as well as startups like MicroUnity. Some media processors target communications-intensive applications like cable modems, set-top boxes, telephone switches, videophones, cellular telephones and other wireless mobile devices, including PDAs, while others focus on personal computer applications, and still others aim to give everyday appliances the ability to process and transmit audio, video and graphics. While they are all similar in concept, each media processor's manufacturer is targeting a different market segment where multimedia functionality is required. As a result, each media processor reflects a different design philosophy and may include specialized hardware appropriate for the target market.

In the personal computer market, for example, knowing that Pentium-class or better host CPU will be present allows the media processor designer to simplify the design and keep costs down by letting the host CPU do some of the work. With this coprocessor arrangement, for example, the PC host processor can perform many of the floating point calculations needed for realistic 3D graphics, eliminating the need for a complex floating-point processor on the media processor die. A PC-hosted media processor must also support legacy hardware standards, such as Creative Labs SoundBlaster compatibility and various graphics standards, and adapt well to the PC architecture, including key host bus interfaces. A multimedia subsystem using a media processor could easily be implemented directly on the PC motherboard, or as a plug-in card. The first products using media processors will appear on the market this year.

Media Processors -- The Next Logical Step

Performing several multimedia functions on a single chip is not a new idea. Digital signal processors (DSPs) can be programmed to perform a number of multimedia functions, one at a time, and have been finding use in audio and telephony applications, including modems, speech processing and sound generation. But DSPs lack the processing power to be programmed to perform more than one task at a time, and typically cannot be programmed to perform graphics or video-based functions because their architectures, based on older technology, cannot process the volume of data required fast enough.

Other solutions combine multiple static functions on a single chip. While these chips have the bandwidth to perform complex graphics and video functions, and can perform more than one task at a time, all of their functions are hard wired, with dedicated silicon for each task, and cannot have new functions added or existing functions updated. The static-function approach lacks flexibility and doesn't make very efficient use of the silicon, requring higher transistor counts, larger, more costly dies and larger off-chip memories. Any time a function is not being used, the associated circuitry sits idle. Functions that once had their own private memory space must now be made to share one, requiring some form of additional memory management kernel. What's more, these chips cannot keep up with the fluid nature of the multimedia market, with its constantly changing needs and standards, nor do they provide manufacturers with the efficiencies of using a single part across a range of products over time.

While the media processor shares many similarities with the DSP, it is the result of new thinking, a fresh approach to the challenge of bringing high-quality multimedia functionality to the mainstream. Unbridled by legacy investments in older technology, media processor manufacturers have had the luxury of starting with a clean slate when designing their components.

Supercomputer on a Chip

Providing any combination of multimedia functions simultaneously requires a device capable of performing billions of operations per second. MPEG decoding, for example, requires 1 to 2 billion operations per second. 3D graphics rendering requires another billion operations per second to achieve 1 million triangle per second performance. And real-time MPEG-1 encoding requires tens of billions of operations per second. To obtain this performance, media processors are designed to do more than one thing at a time.

High-bandwidth, supercomputer-like architectures, parallel processing, very long instruction word (VLIW) and single-instruction/multiple-data (SIMD) execution and vector processing are some of the technologies media processors employ. The media processor's instruction set also contains several specialized instructions aimed at the performance sensitive "inner-loop" functions used extensively in discreet cosine transforms, bitblt, adaptive filtering and other multimedia-related data processing functions. These instructions provide performance boosts without requiring application specific hardware, holding the lid on cost. The immense power of media processor -- as high as 20 billion operations per second -- enables a single device to replace the multiple subsystems currently used to perform all the required multimedia functions, including:

The media processor can be programmed to perform virtually any combination of these individual multimedia tasks simultaneously. By using a single, high-powered media processor to handle all multimedia functions, no hard-wired, function-specific circuitry is ever sitting idle and no precious and costly silicon real estate is wasted if a particular function is not being used.

Sharing the same memory space among all the multimedia functions provides additional benefits as well. With video and 3D graphics sharing the same memory space in PC applications, for example, texture mapping of real-time video frames onto 3D objects becomes more managable. It becomes possible for game developers to use MPEG compressed video sequences to represent characters instead of the more limited number of uncompressed bitmaps they now use, resulting in more realism and a better game experience for the players.

A Boon to OEMs

The software-driven media processor provides obsolescence protection for both OEMs and consumers. Manufacturers can make sure their products conform to the most recent multimedia standards, new capabilities can be added and outdated ones removed, all through software, even after a product has been shipped. The media processor provides economies of scale, and resulting lower costs, not possible with fixed-function devices by allowing OEMs to create common hardware platforms supporting late binding of product feature sets. The same media processor, used in each product, is simply programmed to perform only those functions necessary for that product. The additional circuitry that would be required for the omitted functions is simply left off the identical circuit board.

The media processor is also far more cost-effective and performance-efficient than fixed-function approaches. The hardware efficiency of the media processor translates to fewer components, less board area, higher reliability, fewer integration problems and lower cost.

MMX

The software-driven approach to multimedia processing got another support boost recently with Intel's announcement of the P55C Pentium-class CPU with multimedia extensions to its instruction set (MMX). These CPUs can add valuable, incremental multimedia computing power to PCs and other systems with media processors present. Media processors, because they are software driven, are flexible enough to work with MMX-enhanced CPUs for even greater overall multimedia performance.

MMX by itself will not be sufficient to meet the requirements for mainstream multimedia performance, even over time. But the combined performance of media processors and MMX-enhanced CPUs, however, will be able to meet most user demand for multimedia performance.

A good analogy for the value obtained through the pairing of a media processor with an MMX-enhanced CPU is the way a GUI accelerator chip helps a standard x86 processor. While the x86 is capable of GUI acceleration alone, the quality of the user experience is substantially improved for a very small added cost relative to the cost of the x86. For this reason, GUI accelerators are found in virtually every PC manufactured today. For a small added cost relative to the cost of the MMX-enhanced CPU, a media processor can replace the GUI accelerator in the PC while providing a compelling improvement in the user's multimedia experience. The Best Solution for Multimedia

The continuing escalation in demand for the latest multimedia features will force computer, consumer electronics and other manufacturers to harness all the multimedia processing power they can, as affordably as possible. Media processors -- built specifically for multimedia's natural data types, dedicated to task, mass manufactured for low cost and improving dramatically over time -- are the best solution for these manufacturers to keep pace with this demand.

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