1. Embedded System:Introduction 1 Introduction What is an embedded system? Embedded system market trends Characteristics of embedded systems Embedded system requirements Design of embedded systems Trend of embedded systems

2. Embedded System:Introduction 2 What Is an Embedded System? What is a system? –A set or arrangement of things so related or connected as to form a unity or organic whole. What is embedded? –To be set or fixed firmly in a surrounding mass. What is an embedded system? –An electronic system embedded within a given plant or external process to perform a specific function, which has to respond to certain inputs within a prescribed time constraint. The external process comprises both a physical system and also humans performing some supervising or parameter setting tasks.

3. Embedded System:Introduction 3

4. 4 Components of an Embedded System Software –Operating systems, device drivers, application programs that Provide system features and flexibility Hardware –Processor cores, DSP cores, ASICs, Memorys, I/O devices, SOCs (system-on-chip), communication ICs, ADC/DAC, …, are used for achieving the required performance and sometimes the security.

5. Embedded System:Introduction 5 Characteristics Perform a single or tightly knit set of functions, which is not usually general purpose, i.e., application specific Increasingly high-performance and real-time constraints Reactive, i.e., an embedded system (ES) must respond to an input stimulus Distributed, i.e., many correlated components (processors) are coordinated to react the input stimuli coming from the various positions of an ES. Cost, reliability(long life), power are important attributes in design decision, usually under the constraints of limited hardware resource.

6. Embedded System:Introduction 6 Real-Time Requirements A real-time system consists of tasks under deadline constraints –Notion of time typically is global Hard real-time versus soft real-time systems –Hard real-time: the tasks must complete by specified deadlines, e.g., flight control, collision alert, the warning coming from most of the medical equipment, etc. –Soft real-time: task execution may go beyond specified deadlines without catastrophic failures,.e.g., display update,...

7. Embedded System:Introduction 7 Applications Consumer electronics, e.g., cameras, camcorders, …. Home appliance, e.g., washers, microwave ovens, …. Medical instruments, e.g., heart-beat monitor for new- born, contraction monitor for womb,…. Automobiles, e.g., anti-lock braking, engine control, …. Industrial process controllers Avionics and defense systems Computer/communication products, e.g., network printers, fax, PDA, cellular phones, software modem, …. Multimedia applications, e.g., interactive game boxes, TV set-top-box,...

8. Embedded System:Introduction 8 Diversified Computing Requirements Infrared remote controller –Required least amount of computing power, but optimized for code size and power Pocket remote control RF transmitter –100 KIPS, optimized for code size and power Industrial equipment controller –1 MIPS, 1 MB memory –safety-critical Military signal processing and multimedia applications –1 GFLOPS, 1 GB/sec IO, 32 MB –Software for high performance

9. Embedded System:Introduction 9 Embedded System Market Market size for embedded systems: US$ 31 B –General purpose computing: US$ 46.5 B Micro-controller market: US$4.6 B, +18% annual growth rate –Versus +10% annual growth rate for general purpose processors Embedded system market will finally surpass computing marketing.

10. Embedded System:Introduction 10 Driving Forces Computing technologies are proliferating to non- computing domains –portable devices, medical instrumentation and imaging, information appliance Increasing the need for product personalization –Hand-held devices Increasing the need for entertainment –Game boxes Advance in semiconductor technologies and design methodologies –reducing manufacturing and design costs

11. Embedded System:Introduction 11 Embedded System Design Defining Specifications Modeling the system to be designed algorithmically; Refining the function to be implemented into smaller interacting pieces; HW-SW partitioning by allocating elements in the refined model to either (1) HW units, or (2) SW running on custom hardware or a general processor; Scheduling the times at which the functions are executed; Mapping a functional description into (1) software that runs on a processor, or (2) a collection of custom, semi- custom, or commodity HW.

12. Embedded System:Introduction 12 Diversified Design Requirements Cost Size Power Reliability –safety-critical –viable for a harsh environment Performance Real-time constraint Product differentiation Time to market pressure Combination of HW and SW –New design paradigms, techniques, and tools

13. Embedded System:Introduction 13 Embedded System Design Defining Specifications Modeling the system to be designed algorithmically; Refining the function to be implemented into smaller interacting pieces; HW-SW partitioning by allocating elements in the refined model to either (1) HW units, or (2) SW running on custom hardware or a general processor; Scheduling the times at which the functions are executed; Mapping a functional description into (1) software that runs on a processor, or (2) a collection of custom, semi- custom, or commodity HW.

14. Embedded System:Introduction 14 What is HW/SW Co-design? The act of bridging the gap between the HW and SW. Traditional design approach –SW and HW partitioning is decided at an early stage, and designs proceed separately from then onward. HW/SW co-design –A flexible design strategy, wherein the HW/SW designs proceed in parallel, with feedback and interaction occurring between the two as the design progresses. –Final HW/SW partitioning and allocation is made after evaluating trade-offs and performance of options.

15. Embedded System:Introduction 15 CAD for Embedded System Design Co-design: Joint optimization of hardware and software –Cost-performance tradeoffs as a part of product implementation, as opposed to product specification. That is, we can perform design space exploration across the HW and SW boundary Co-synthesis: Synthesis assisting co-design –Design derived from (formal) specifications –Rapid exploration of design alternatives

16. Embedded System:Introduction 16 Disciplines in Embedded System Design The design of embedded systems spans several different disciplines in CS and EE Application domain (Signal processing,….) Software engineering (Programming languages, compilers, …) VLSI (computer aided) design Parallel/distributed system design –Networking and communications Real-time systems (Real-time OS) Computer organization and architecture Input/output, sensor and actuators technologies, etc.

17. Embedded System:Introduction 17 Trends in Embedded Systems Increasing code size –Average code size: 16K~64KB in 1992, 64K~512KB in 1996 –Migration from assembling coding to high-level languages Reuse of hardware and software components –Processors (micro-controllers, DSPs) –Software components (drivers) Increasing integration and system complexity –integration of RF, DSP, networking interface –32-bit processors, IO processors, Network processors Increasing more intelligent

18. Embedded System:Introduction 18 Digital Signal Processing in ES Continued digitalization of signals increasing the role of DSP –Signals are represented digitally as sequence of samples –ADCs are moving closer to signals Even RF, IF processing in digital domain Typical DSP processing –Filtering, averaging, FFT, device control, etc. –Speech: codec, processing, user interface, etc –Communications: modulation, demodulation, noise/echo cancellation, encoding, decoding, equalization, etc.

19. Embedded System:Introduction 19 Example 1 Nike psa –Delivers up to 120 minutes of digital music. –Plays either MP3 or WMA digital audio formats downloaded from the Internet. Universal Information Appliance

20. Embedded System:Introduction 20 Summary What is an embedded system? Embedded system market trends Characteristics of embedded systems Embedded system requirements Design of embedded systems Trend of embedded systems