PlatformBased Design Part 1 Introduction Wayne Wolf Princeton
Platform-Based Design Part 1, Introduction Wayne Wolf Princeton University Joerg Henkel NEC C&C Lab 1
Course outline z Introduction: Wayne z Methodologies: Joerg z Applications: Wayne z Tools, business models: Joerg 2
Competing imperatives z Technology push: y high-volume products; y feasible design. z Marketing push: y fast turnaround; y differentiated products. IBM Power. PC 750 Nokia 9210 3
What is a platform? z A partial design: y for a particular type of system; y includes embedded processor(s); y may include embedded software; y customizable to a customer’s requirements: xsoftware; xcomponent changes. IBM Core. Connect 4
The design productivity gap 5
Why platforms? z Any given space has a limited number of good solutions to its basic problems. z A platform captures the good solutions to the important design challenges in that space. z A platform reuses architectures. 6
Alternative to platforms z General-purpose architectures. y May require much more area to accomplish the same task. y Often much less energy-efficient. z Reconfigurable systems. y Good for pieces of the system, but tough to compete with software for miscellaneous tasks. Intel Xilinx 7
Standards and platforms z Many high-volume markets are standards-driven: y wireless; y multimedia; y networking. MPEG Tampere meeting z Standard defines the basic I/O requirements. bluetooth. com 8
Standards and platforms, cont’d. z Systems house chooses implementation of standards functions: y improved quality, lower power, etc. z Product may be differentiated by added features: y cell phone user interface. z Standards encourage platform-based design. 9
Platform vs. full-custom z Platform has many fewer degrees of freedom: y harder to differentiate; y can analyze design characteristics. z Full-custom: y extremely long design cycles; y may use less aggressive design styles if you can’t reuse some pieces. 10
Platforms and embedded computing z Platforms rely on embedded processors: y can be customized through software; y can put considerable design effort into the CPU. z Many platforms are complex heterogeneous multiprocessors. Agere Star. Pro 11
Platforms and IP-based design z Platforms use IP: y CPUs; y memories; y I/O devices. z Platforms are IP at the next level of abstraction. 12
Advantages of platform-based design z Fast time-to-market. z Reuse system design---hardware, software. z Allows chip to be customized to add value. 13
Costs of platform-based design z Masks. z NRE: design of the platform + customization. z Design verification. 14
Two phases of platform-based design z Design the platform. z Use the platform. requirements past designs platform user needs product 15
Division of labor z Platform design: y choose, characterize hardware units; y create the system architecture; y optimize for performance, power. z Platform-based product design: y modify hardware architecture; y optimize programs. 16
Semiconductor vs. systems house z Semiconductor house designs the platform. z Systems house customizes the platform for its system: y customization may be done in-house or by contractor. 17
Platform design challenges z Does it satisfy the application’s basic requirements? z Is it sufficiently customizable? And in the right ways? z Is it cost-effective? z How long does it take to turn a platform into a product? 18
Platform design methodology z Size the problem. y How much horsepower? How much power? z Develop an initial architecture. z Evaluate for performance, power, etc. z Evaluate customizability. z Improve platform after each use. 19
Platform use challenges z How do I understand the platform’s design? z How do I modify it to suit my needs? z How do I optimize for performance, power, etc. ? 20
Platform use methodology z Start with reference design, evaluate differences required for your features. z Evaluate hardware changes. z Implement hardware and software changes in parallel. z Integrate and test. 21
Modeling languages z System. C (www. systemc. org). z Spec. C z (www. specc. org). Spec. C 22
Verification methodologies z Execute high-level models. z Co-simulation. z Run software on sample chip. 23
Design refinement z Bad news: y hard to learn the platform in order to change it. Worldwide shipping by UPS. . . roughly US$ 50 for CD and US$ 100 for paper copy (1500 pages, heavy!) Bluetooth. com z Good news: y an existing design can be measured, analyzed, and refined. 24
Software and hardware reuse z Want to reuse as many hardware components as possible: y known performance, power. z Want to use software libraries where possible. z RTOS simplifies design of multi-tasking systems. 25
But who does it? z Do we use a disciplined, analytical process to create a platform that can be used for a series of designs? Or z Do we grab the last similar design and start hacking? 26
How do I choose a platform? z Ideal: y evaluate aspects of the platform critical to my product’s requirements. z Base: Merck y marketing/sales decision. NEW! 27
Summary z Trends encourage platform-based design. z Two phases: design platform, use it. z Iterative design style helps in evaluation, but requires steep learning curve. z Pure form of platform-based design may be rare in practice. 28
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