Introduction to Embedded System 成功大學資訊工程系 陳 培 殷 嵌入式系統概論

PCB PC: a general-purpose computing system PC Pentium

Embedded System: a special-purpose computing system Most embedded systems are designed for 1.Special purpose (customizing and non-programmable) 2.Real time applications 3. Stable applications 4. Automatic applications Embedded System 嵌入式系統 (1/2) * * * * remote controller PDA, mobile phone PCB

uP UART A/D USB ROM RAM Embedded System (2/2) Traditional embedded systems uses low-level processors only. ARM PCI MPEG ASIC FLASH ROM RAM DSP AMBA Advanced embedded systems ( many processors ) 8 bit-8051 mp3 USB

Applications Information Appliances (IA): 1. Smart phone, VOIP 2. Digital TV, set-top box 3. PlayStation 4. PDA, mp3 player 5. Camera, DV 6. Air-conditioner, microwave oven, refrigerator, vacuum cleaner, sensor network 7. Motorcycles 8. Car (abs, engine firing, air bag) >100 processors 9. … Ubiquitous computing (many computers for everyone)

Requirements 1. Friendly user interface 2. Multiple-rate matching 3. Short time-to-market 4. Real-time (Speed) 5. Cost 6. Power consummation/dissipation (portable?) (cooling strategy and battery  how?) 7. Distributed property ARM PCI MPEG ASIC FLASH ROM RAM DSP AMBA mp3 USB

Power Consumption The basic equation to represent the average power consumption in CMOS ： Supply voltage Capacitance Clock frequency (*) Average number of 0-to-1 transitions (*)  Transitions reduction, Sleep mode Gray code

Distributed Property Machine #1 OS#1 Machine #2 OS#2 Machine #3 OS#3 Machine #4 OS#4 Network Distributed applications Middleware Advantages of distributed system: cost, reliability, extension Inter-process communication, problems of CS and deadlock Fault tolerance  information redundancy, time redundancy, physical redundancy

Design Flow Specification System Architecture Hardware Design Software Design System Integration System Verification/Testing Hardware/software partition is very difficult? Cost, time, transmission ARM PCI MPEG ASIC FLASH ROM RAM DSP AMBA mp3 USB

Jobs for Embedded System 1.Designer for chips 2.Designer for system/devices 3.Designer for firmware/software Three main components for embedded system: ARM PCI MPEG ASIC FLASH ROM RAM DSP AMBA mp3 USB Not x86-based design

Hardware Design -- Chip (1/4) The basic design flow for digital ASIC Describe circuits with hardware description language (HDL 硬體描述語言 )  VHDL and Verilog Synthesis ( 合成 ) the circuits …. application specific integrated circuit (ASIC 晶片 ) such as USB, MPEG, mp3, DSP, …. ARM PCI MPEG ASIC FLASH ROM RAM DSP AMBA mp3 USB

Hardware Design -- Chip (2/4) Full-Custom IC design Semi-Custom IC design Digital circuit Analog circuit Digital circuit What you can do (logic/digital system)

Hardware Design -- Chip (3/4) if (a==b) if (c==1) d=f; else d=1; else d=0; a b c f d f c a b d Translate into Boolean Representation Optimize + Map HDL Source Target Technology Synthesis = Translation+Optimization+Mapping Synthesis = Translation+Optimization+Mapping Process of logic synthesis Software EDA tools for synthesis

Hardware Design -- Chip (4/4) FPGA or CPLD Real ASIC chip less flexible, long design cycle, higher speed, larger-scale production to reduce price more flexible, shorter design cycle, lower speed, lower utilization, suitable for smaller production Standard cell PLD Fab (TSMC, UMC,..) Two implementations of digital chips Xilinx, Altera ASIC Total solution: Target chip + other chips (SDK, user manuals)

Hardware Design -- System ARM PCI MPEG USB FLASH ROM RAM DSP AMBA ASIC Input devices: keyboard, touch screen, switch, button,.. Output devices: monitor, LCD, LED, … Extended devices: compact flash card (CF), PCMCIA, SD, MS (for storage, wireless communication, I/O) Power system: Transmission Interface: PCI, USB, IEEE 1394, UART, … Wireless: , bluetooth Bus: AMBA ( Advanced Microcontroller Bus Architecture ) Input devices Output devices

ARM PCI MPEG USB FLASH ROM RAM DSP AMBA ASIC Devices drivers for I/O devices, extended devices, transmission interface Assembly codes and C codes for some dedicated CPUs (ARM, x86, MIPS, PowerPC..)  Architectures and instruction sets of different CPUs, DMA,… Input devices Output devices Firmware/Software Design (1/3)

Firmware/Software Design (2/3) ARM PCI MPEG USB FLASH ROM RAM DSP AMBA ASIC Input devices Output devices Embedded OS: WinCE, Palm OS, Linux, JAVA uClinux (<=512KB, without MMU)  Real time OS (without virtual memory) process preemption, interrupt handling  as small as possible (memory, with/without MMU)  distributed embedded system (+ fault tolerance)

Application Software: wireless communication, network, multimedia, health, convenience, Web, ….  Porting a customized embedded system on different machines is very difficult (need large modification)  Good opportunity Firmware/Software Design (3/3)

Present/Future Chip: tens of millions of transistors or more (.35,.25,.18,.065 製程技術 ) Design shifts from ASIC/board to system/board System on a Board (printed circuit board) System on a chip PCB System-on-a chip is possible (the whole system is built in a single chip) Everything is small !!! ARM PCI MPEG ASIC FLASH ROM RAM DSP AMBA FPGA USB SW SoC chip