1. Embedded Systems Design: A Unified Hardware/Software Introduction 1 Chapter 1: Introduction

2. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 2 Outline Embedded systems overview –What are they? Design challenge – optimizing design metrics Technologies –Processor technologies –IC technologies –Design technologies

3. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 3 Embedded systems overview Computing systems are everywhere Most of us think of “desktop” computers –PC’s –Laptops –Mainframes –Servers But there’s another type of computing system –Far more common...

4. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 4 Embedded systems overview Embedded computing systems –Computing systems embedded within electronic devices –Hard to define. Nearly any computing system other than a desktop computer –Billions of units produced yearly, versus millions of desktop units –Perhaps 50 per household and per automobile Computers are in here... and here... and even here... Lots more of these, though they cost a lot less each.

5. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 5 A “short list” of embedded systems And the list goes on and on Anti-lock brakes Auto-focus cameras Automatic teller machines Automatic toll systems Automatic transmission Avionic systems Battery chargers Camcorders Cell phones Cell-phone base stations Cordless phones Cruise control Curbside check-in systems Digital cameras Disk drives Electronic card readers Electronic instruments Electronic toys/games Factory control Fax machines Fingerprint identifiers Home security systems Life-support systems Medical testing systems Modems MPEG decoders Network cards Network switches/routers On-board navigation Pagers Photocopiers Point-of-sale systems Portable video games Printers Satellite phones Scanners Smart ovens/dishwashers Speech recognizers Stereo systems Teleconferencing systems Televisions Temperature controllers Theft tracking systems TV set-top boxes VCR’s, DVD players Video game consoles Video phones Washers and dryers

6. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 6 Some common characteristics of embedded systems Single-functioned –Executes a single program, repeatedly Tightly-constrained –Low cost, low power, small, fast, etc. Reactive and real-time –Continually reacts to changes in the system’s environment –Must compute certain results in real-time without delay

7. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems are dedicated to specific tasks, whereas PCs are generic computing platforms. Another name for an embedded microprocessor is a dedicated microprocessor. It is programmed to perform only one, or a few, specific tasks. Changing the task is usually associated with obsolescing the entire system and redesigning it. –The processor that runs a mobile heart monitor/defibrillator is not expected to run a spreadsheet or word processor. Where as general-purpose processor, must be able to support a wide array of applications with widely varying processing requirements. Because your PC must be able to service the most complex applications with the same performance as the lightest application, the processing power on your desktop is truly awesome. –Thus, it wouldn’t make much sense, either economically or from an engineering standpoint, to put an INTEL Core I3, or similar processor, inside the coffeemaker on your kitchen counter. 7

8. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems are supported by a wide array of processors and processor architectures. –Most students you have never programmed on any platform except the X86 (Intel) –today more than 140 different microprocessors are available from more than 40 semiconductor vendors. These vendors are in a daily battle with each other to get the design-win (be the processor of choice) for the next wide-body jet or the next Internet- based soda machine. 8

9. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems are usually cost sensitive. –The cost that you must consider most of the time is system cost. The cost of the processor is a factor, but, if you can eliminate a printed circuit board and connectors and get by with a smaller power supply by using a highly integrated microcontroller instead of a microprocessor and separate peripheral devices, you have potentially a greater reduction in system costs, even if the integrated device is significantly more costly than the discrete device. 9

10. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems have real-time constraints –Real-time constraints generally are grouped into two categories: time- sensitive constraints and time-critical constraints. –If a task is time critical, it must take place within a set window of time, or the function controlled by that task fails. Controlling the flight-worthiness of an aircraft is a good example of this. If the feedback loop isn’t fast enough, the control algorithm becomes unstable, and the aircraft won’t stay in the air. –A time-sensitive task can die gracefully. If the task should take, for example, 4.5ms but takes, on average, 6.3ms, then perhaps the inkjet printer will print two pages per minute instead of the design goal of three pages per minute. 10

11. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different If an embedded system is using an operating system at all, it is most likely using a real-time operating system (RTOS) –Like embedded processors, embedded operating systems also come in a wide variety of flavors and colors. –RTOSs are not democratic. They need not give every task that is ready to execute the time it needs. –RTOSs give the highest priority task that needs to run all the time it needs. If other tasks fail to get sufficient CPU time, it’s the programmer’s problem. Green Hills Software INTEGRITY Wind River VxWorks QNX Neutrino FreeRTOS Micrium µC/OS-II, III Windows CE TI-RTOS Kernel (previously called DSP/BIOS) 11

12. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different The implications of software failure is much more severe in embedded systems than in desktop systems. –We all know of the tragic consequences of a medical radiation machine that miscalculates a dosage. How do we know when our code is bug free? How do you completely test complex software that must function properly under all conditions? –software failure is far less tolerable in an embedded system than in your average desktop PC. That is not to imply that software never fails in an embedded system, just that most embedded systems typically contain some mechanism, such as a watchdog timer, to bring it back to life if the software loses control. 12

13. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems often have power constraints. –Power constraints affect the processor choice, its speed, and its memory architecture. –The constraints imposed by the system requirements will likely determine whether the software must be written in assembly language, rather than C or C++, because the absolute maximum performance must be achieved within the power budget. –Power requirements are dictated by the CPU clock speed and the number of active electronic components (CPU, RAM, ROM, I/O devices, and so on). 13

14. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems often must operate under extreme environmental conditions. –Embedded systems are everywhere. Embedded systems must run in aircraft, in the polar ice, in outer space, etc –If you’ve wondered why a simple processor, such as the 8086 from Intel, should cost several thousands of dollars in a missile, think paperwork and environment. 14

15. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems have far fewer system resources than desktop systems. –this is because it is dedicated to a few well-defined tasks and nothing else. –The number of inputs and outputs are usually so limited, the designers are forced to overload and serialize the functions of one or two input devices. 15

16. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems often store all their object code in ROM. –Even your PC has to store some of its code in ROM. ROM is needed in almost all systems to provide enough code for the system to initialize itself (boot-up code). –However, most embedded systems must have all their code in ROM. This means severe limitations might be imposed on the size of the code image that will fit in the ROM space. However, it’s more likely that the methods used to design the system will need to be changed because the code is in ROM. 16

17. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis Why Embedded Systems Are Different Embedded systems require specialized tools and methods to be efficiently designed. –The embedded system is so different in so many ways, it’s not surprising that specialized tools and methods must be used to create and test embedded software. –example—the need to set a break-point at an instruction boundary located in ROM. A ROM Emulator 17

18. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 18 An embedded system example -- a digital camera Microcontroller CCD preprocessorPixel coprocessor A2D D2A JPEG codec DMA controller Memory controllerISA bus interfaceUARTLCD ctrl Display ctrl Multiplier/Accum Digital camera chip lens CCD Single-functioned -- always a digital camera Tightly-constrained -- Low cost, low power, small, fast Reactive and real-time -- only to a small extent

19. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis An embedded system example -- a digital camera 19 D2A/A2D circuits convert analog images to digital and digital to analog, respectively. CCD preprocessor is a charge-coupled device preprocessor. JPEG codec compresses and decompresses an image using the JPEG2 compression standard. Pixel coprocessor aids in rapidly displaying images. Memory controller controls access to a memory chip also found in the camera, DMA controller enables direct memory access without requiring the use of the microcontroller. UART enables communication with a PC’s serial port for uploading video frames, ISA bus interface enables a faster connection with a PC’s ISA bus. LCD ctrl and Display ctrl circuits control the display of images on the camera’s liquid- crystal display device. Multiplier/Accum circuit assists with certain digital signal processing. microcontroller, which is a processor that controls the activities of all the other circuits. We can think of each device as a processor designed for a particular task, while the microcontroller is a more general processor designed for general tasks.

20. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 20 Design challenge – optimizing design metrics Obvious design goal: –Construct an implementation with desired functionality Key design challenge: –Simultaneously optimize numerous design metrics Design metric – A measurable feature of a system’s implementation –Optimizing design metrics is a key challenge

21. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 21 Design challenge – optimizing design metrics Common metrics –Unit cost: the monetary cost of manufacturing each copy of the system, excluding NRE cost –NRE cost (Non-Recurring Engineering cost): The one-time monetary cost of designing the system –Size: the physical space required by the system –Performance: the execution time or throughput of the system –Power: the amount of power consumed by the system –Flexibility: the ability to change the functionality of the system without incurring heavy NRE cost

22. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 22 Design challenge – optimizing design metrics Common metrics (continued) –Time-to-prototype: the time needed to build a working version of the system –Time-to-market: the time required to develop a system to the point that it can be released and sold to customers –Maintainability: the ability to modify the system after its initial release –Correctness, safety, many more

23. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 23 Design metric competition -- improving one may worsen others Expertise with both software and hardware is needed to optimize design metrics –Not just a hardware or software expert, as is common –A designer must be comfortable with various technologies in order to choose the best for a given application and constraints SizePerformance Power NRE cost Microcontroller CCD preprocessorPixel coprocessor A2D D2A JPEG codec DMA controller Memory controllerISA bus interfaceUARTLCD ctrl Display ctrl Multiplier/Accum Digital camera chip lens CCD Hardware Software

24. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 24 Time-to-market: a demanding design metric Time required to develop a product to the point it can be sold to customers Market window –Period during which the product would have highest sales Average time-to-market constraint(time-window) is about 8 months Delays can be costly Revenues ($) Time (months)

25. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 25 Losses due to delayed market entry Simplified revenue model –Product life = 2W, peak at W –Time of market entry defines a triangle, representing market penetration –Triangle area equals revenue Loss –The difference between the on- time and delayed triangle areas On-time Delayed entry Peak revenue Peak revenue from delayed entry Market rise Market fall W2W Time D On-time Delayed Revenues ($)

26. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 26 Losses due to delayed market entry (cont.) Area = 1/2 * base * height –On-time = 1/2 * 2W * W –Delayed = 1/2 * (W-D+W)*(W-D) Percentage revenue loss = (D(3W-D)/2W 2 )*100% Try some examples On-time Delayed entry Peak revenue Peak revenue from delayed entry Market rise Market fall W2W Time D On-time Delayed Revenues ($) –Lifetime 2W=52 wks, delay D=4 wks –(4*(3*26 –4)/2*26^2) = 22% –Lifetime 2W=52 wks, delay D=10 wks –(10*(3*26 –10)/2*26^2) = 50% –Delays are costly!

27. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 27 NRE and unit cost metrics Costs: –Unit cost: the monetary cost of manufacturing each copy of the system, excluding NRE cost –NRE cost (Non-Recurring Engineering cost): The one-time monetary cost of designing the system –total cost = NRE cost + unit cost * # of units –per-product cost = total cost / # of units = (NRE cost / # of units) + unit cost Example –NRE=$2000, unit=$100 –For 10 units –total cost = $2000 + 10*$100 = $3000 –per-product cost = $2000/10 + $100 = $300 Amortizing NRE cost over the units results in an additional $200 per unit

28. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 28 NRE and unit cost metrics Compare technologies by costs -- best depends on quantity –Technology A: NRE=$2,000, unit=$100 –Technology B: NRE=$30,000, unit=$30 –Technology C: NRE=$100,000, unit=$2 But, must also consider time-to-market

29. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 29 The performance design metric Widely-used measure of system, widely-abused –Clock frequency, instructions per second – not good measures –Digital camera example – a user cares about how fast it processes images, not clock speed or instructions per second Latency (response time) –Time between task start and end –e.g., Camera’s A and B process images in 0.25 seconds Throughput –Tasks per second, e.g. Camera A processes 4 images per second –Throughput can be more than latency seems to imply due to concurrency, e.g. Camera B may process 8 images per second (by capturing a new image while previous image is being stored). Speedup of B over S = B’s performance / A’s performance –Throughput speedup = 8/4 = 2

30. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 30 Three key embedded system technologies Technology –A manner of accomplishing a task, especially using technical processes, methods, or knowledge Three key technologies for embedded systems –Processor technology –IC technology –Design technology

31. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 31 Processor technology The architecture of the computation engine used to implement a system’s desired functionality Processor does not have to be programmable –“Processor” not equal to general-purpose processor Application-specific Registers Custom ALU DatapathController Program memory Assembly code for: total = 0 for i =1 to … Control logic and State register Data memory IRPC Single-purpose (“hardware”) DatapathController Control logic State register Data memory index total + IRPC Register file General ALU DatapathController Program memory Assembly code for: total = 0 for i =1 to … Control logic and State register Data memory General-purpose (“software”)

32. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 32 Processor technology Processors vary in their customization for the problem at hand total = 0 for i = 1 to N loop total += M[i] end loop General-purpose processor Single-purpose processor Application-specific processor Desired functionality

33. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 33 General-purpose processors Programmable device used in a variety of applications –Also known as “microprocessor” Features –Program memory –General datapath with large register file and general ALU User benefits –Low time-to-market and NRE costs –High flexibility “Pentium” the most well-known, but there are hundreds of others IRPC Register file General ALU DatapathController Program memory Assembly code for: total = 0 for i =1 to … Control logic and State register Data memory

34. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 34 Single-purpose processors Digital circuit designed to execute exactly one program –a.k.a. coprocessor, accelerator or peripheral Features –Contains only the components needed to execute a single program –No program memory Benefits –Fast –Low power –Small size Datapath Controller Control logic State register Data memory index total +

35. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 35 Application-specific processors Programmable processor optimized for a particular class of applications having common characteristics –Compromise between general-purpose and single-purpose processors Features –Program memory –Optimized datapath –Special functional units Benefits –Some flexibility, good performance, size and power IRPC Registers Custom ALU DatapathController Program memory Assembly code for: total = 0 for i =1 to … Control logic and State register Data memory

36. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 36 IC technology The manner in which a digital (gate-level) implementation is mapped onto an IC –IC: Integrated circuit, or “chip” –IC technologies differ in their customization to a design –IC’s consist of numerous layers (perhaps 10 or more) IC technologies differ with respect to who builds each layer and when sourcedrain channel oxide gate Silicon substrate IC packageIC

37. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 37 IC technology Three types of IC technologies –Full-custom/VLSI –Semi-custom ASIC (gate array and standard cell) –PLD (Programmable Logic Device) To understand the differences among IC technologies, we must first recognize that semiconductors consist of numerous layers. The bottom layers form the transistors. The middle layers form logic gates. The top layers connect these gates with wires(routing).

38. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 38 Full-custom/VLSI All layers are optimized for an embedded system’s particular digital implementation –Placing transistors –Sizing transistors –Routing wires Benefits –Excellent performance, small size, low power Drawbacks –High NRE cost (e.g., $300k), long time-to-market

39. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 39 Semi-custom Lower layers are fully or partially built –Designers are left with routing of wires and maybe placing some blocks Benefits –Good performance, good size, less NRE cost than a full- custom implementation (perhaps $10k to $100k) Drawbacks –Still require weeks to months to develop

40. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 40 PLD (Programmable Logic Device) All layers already exist –Designers can purchase an IC –Connections on the IC are either created or destroyed to implement desired functionality –Field-Programmable Gate Array (FPGA) very popular Benefits –Low NRE costs, almost instant IC availability Drawbacks –Bigger, expensive (perhaps $30 per unit), power hungry, slower

41. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 41 Moore’s law The most important trend in embedded systems –Predicted in 1965 by Intel co-founder Gordon Moore IC transistor capacity has doubled roughly every 18 months for the past several decades 10,000 1,000 100 10 1 0.1 0.01 0.001 Logic transistors per chip (in millions) 198119831985198719891991199319951997199920012003200520072009 Note: logarithmic scale

42. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 42 Moore’s law Wow –This growth rate is hard to imagine, most people underestimate –How many ancestors do you have from 20 generations ago i.e., roughly how many people alive in the 1500’s did it take to make you? 2 20 = more than 1 million people –(This underestimation is the key to pyramid schemes!)

43. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 43 Graphical illustration of Moore’s law 19811984198719901993199619992002 Leading edge chip in 1981 10,000 transistors Leading edge chip in 2002 150,000,000 transistors Something that doubles frequently grows more quickly than most people realize! –A 2002 chip can hold about 15,000 1981 chips inside itself

44. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 44 Design Technology The manner in which we convert our concept of desired system functionality into an implementation Libraries/IP: Incorporates pre- designed implementation from lower abstraction level into higher level. System specification Behavioral specification RT specification Logic specification To final implementation Compilation/Synthesis: Automates exploration and insertion of implementation details for lower level. Test/Verification: Ensures correct functionality at each level, thus reducing costly iterations between levels. Compilation/ Synthesis Libraries/ IP Test/ Verification System synthesis Behavior synthesis RT synthesis Logic synthesis Hw/Sw/ OS Cores RT components Gates/ Cells Model simulat./ checkers Hw-Sw cosimulators HDL simulators Gate simulators

45. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 45 Design productivity exponential increase Exponential increase over the past few decades 100,000 10,000 1,000 100 10 1 0.1 0.01 1983 1981 1987 1989 1991 1993 1985 1995 1997 1999 2001 2003 2005 2007 2009 Productivity (K) Trans./Staff – Mo.

46. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 46 The co-design ladder In the past: –Hardware and software design technologies were very different –Recent maturation of synthesis enables a unified view of hardware and software Hardware/software “codesign” Implementation Assembly instructions Machine instructions Register transfers Compilers (1960's,1970's) Assemblers, linkers (1950's, 1960's) Behavioral synthesis (1990's) RT synthesis (1980's, 1990's) Logic synthesis (1970's, 1980's) Microprocessor plus program bits: “software” VLSI, ASIC, or PLD implementation: “hardware” Logic gates Logic equations / FSM's Sequential program code (e.g., C, VHDL) The choice of hardware versus software for a particular function is simply a tradeoff among various design metrics, like performance, power, size, NRE cost, and especially flexibility; there is no fundamental difference between what hardware or software can implement. system functionality can be implemented in hardware, software, or some combination thereof.

47. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 47 Independence of processor and IC technologies Basic tradeoff –General vs. custom –With respect to processor technology or IC technology –The two technologies are independent General- purpose processor ASIP Single- purpose processor Semi-customPLDFull-custom General, providing improved: Customized, providing improved: Power efficiency Performance Size Cost (high volume) Flexibility Maintainability NRE cost Time- to-prototype Time-to-market Cost (low volume)

48. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 48 Design productivity gap While designer productivity has grown at an impressive rate over the past decades, the rate of improvement has not kept pace with chip capacity 10,000 1,000 100 10 1 0.1 0.01 0.001 Logic transistors per chip (in millions) 100,000 10,000 1000 100 10 1 0.1 0.01 Productivity (K) Trans./Staff-Mo. 198119831985198719891991199319951997199920012003200520072009 IC capacity productivity Gap

49. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 49 Design productivity gap 1981 leading edge chip required 100 designer months –10,000 transistors / 100 transistors/month 2002 leading edge chip requires 30,000 designer months –150,000,000 / 5000 transistors/month Designer cost increase from $1M to $300M 10,000 1,000 100 10 1 0.1 0.01 0.001 Logic transistors per chip (in millions) 100,000 10,000 1000 100 10 1 0.1 0.01 Productivity (K) Trans./Staff-Mo. 198119831985198719891991199319951997199920012003200520072009 IC capacity productivity Gap

50. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 50 The mythical man-month The situation is even worse than the productivity gap indicates In theory, adding designers to team reduces project completion time In reality, productivity per designer decreases due to complexities of team management and communication In the software community, known as “the mythical man-month” (Brooks 1975) At some point, can actually lengthen project completion time! (“Too many cooks”) 102030400 10000 20000 30000 40000 50000 60000 43 24 19 16 15 16 18 23 Team Individual Months until completion Number of designers 1M transistors, 1 designer=5000 trans/month Each additional designer reduces for 100 trans/month So 2 designers produce 4900 trans/month each

51. Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 51 Summary Embedded systems are everywhere Key challenge: optimization of design metrics –Design metrics compete with one another A unified view of hardware and software is necessary to improve productivity Three key technologies –Processor: general-purpose, application-specific, single-purpose –IC: Full-custom, semi-custom, PLD –Design: Compilation/synthesis, libraries/IP, test/verification