CMOS VLSI DesignIntroductionSlide 1 Introduction to CMOS VLSI Design Adnan Aziz The University of Texas at Austin

CMOS VLSI DesignIntroductionSlide 2 Organization  Prerequisites: logic design, basic computer organization –See sample questions  Architecture design versus chip design –Example: innovative processor  Overview of material –Bottom-up approach, CAD tools –See syllabus for individual topics  Course organization –Website, TA, office hours, HW, projects  Acknowledgements –J. Abraham (UT), D. Harris (HMC), R. Tupuri (AMD)

CMOS VLSI DesignIntroductionSlide 3 Course relevance  2007 world wide sales of chips: ~250B$ –Primarily digital –High-margin business –Basis for systems  Most CE graduates work in –VLSI design: Intel, Qualcomm –System design: HP, Cisco –Software: Microsoft, Google

CMOS VLSI DesignIntroductionSlide 4 Systems and Chips  This course: designing ICs –Part of a system: chips + board + software + … –System companies: HP, Cisco –Chip companies: Intel, Qualcomm –nVidia vs. Hercules  Example: high-end data switch –Marketing gives range of specs, architect tries to meet them –Off the shelf chips, embedded software –Why don’t we teach system design?

CMOS VLSI DesignIntroductionSlide 5 Course Goals  Learn to design and analyze state-of-the-art digital VLSI chips using CMOS technology  Employ hierarchical design methods –Understand design issues at the layout, transistor, logic and register-transfer levels –Use integrated circuit cells as building blocks –Use commercial design software in the lab  Understand the complete design flow –Won’t cover architecture, solid-state physics, analog design –Superficial treatment of transistor functioning

CMOS VLSI DesignIntroductionSlide 6 Course Information  Instructor: Adnan Aziz –(512) , –  Course Web Page – Link from my page  Book: Weste and Harris, CMOS VLSI Design: A Circuits and Systems Perspective, AW, 3 rd edition

CMOS VLSI DesignIntroductionSlide 7 Work in the Course  Lectures: largely from text (not always in sequence)  Homework: roughly 6 HWs –Relatively straightforward review questions  Laboratory exercises –Three major exercises dealing with various aspects of VLSI design –Complete each section before the deadline  Grad students: VLSI design project –Design an IP core, architecture to layout Course involves a large amount of work throughout the semester

CMOS VLSI DesignIntroductionSlide 8 What Will We Cover?  Designing chips containing lots of transistors –How basic components work (transistors, gates, flops, memories, adders, –Complexity management: hierarchy and CAD tools  Key issues: –Creating logical structures from transistors –Performance analysis and optimization –Testing: functional and manufacturing –Power consumption, clocking, I/O, etc.

CMOS VLSI DesignIntroductionSlide 9 Exams and Grading  Two midterm tests: in class, open book/notes; samples will be posted –Dates for exams in syllabus –Final: exam (360R), project (382M)  Lab dates in syllabus –Bonus/penalty for early/late submission  Weights for homework, exams, project are in syllabus –Relative weights of MT1/2, Lab 1/2/3 intentionally not specified

CMOS VLSI DesignIntroductionSlide 10 Academic Honesty  Cheating will not be tolerated –OK to discuss homework, laboratory exercises with classmates, TAs and the instructors –However: write the homework and lab exercises by yourself  We check for cheating, and report incidents

CMOS VLSI DesignIntroductionSlide 11 General Principles  Technology changes fast => important to understand general principles –optimization, tradeoffs –work as part of a group –leverage existing work: programs,building blocks  Concepts remain the same: –Example: relays -> tubes -> bipolar transistors -> MOS transistors

CMOS VLSI DesignIntroductionSlide 12 Types of IC Designs  IC Designs can be Analog or Digital  Digital designs can be one of three groups  Full Custom –Every transistor designed and laid out by hand  ASIC (Application-Specific Integrated Circuits) –Designs synthesized automatically from a high-level language description  Semi-Custom –Mixture of custom and synthesized modules

CMOS VLSI DesignIntroductionSlide 13 MOS Technology Trends

CMOS VLSI DesignIntroductionSlide 14 Steps in Design

CMOS VLSI DesignIntroductionSlide 15 System on a Chip Source: ARM

CMOS VLSI DesignIntroductionSlide 16 Laboratory Exercises  Layout and evaluation of standard cells –Familiarity with layout, circuit simulation, timing  Design and evaluation of an ALU, performance optimization –Learn schematic design, timing optimization  Design, synthesis and analysis of a simple controller as part of an SoC –Learn RT-level design, system simulation, logic synthesis and place-and-route  If you already have industrial experience with some of these tools, you can substitute lab for final project –Need my approval; will expect more from project

CMOS VLSI DesignIntroductionSlide 17 Laboratory Design Tools  We will use commercial CAD tools –Cadence, Synopsys, etc.  Commercial software is powerful, but very complex –Designers sent to long training classes –Students will benefit from using the software, but we don’t have the luxury of long training –TAs have experience with the software  Start work early in the lab –Unavailability of workstations is no excuse for late submissions –Plan designs carefully and save work frequently

CMOS VLSI DesignIntroductionSlide 18 Laboratory Exercise 1

CMOS VLSI DesignIntroductionSlide 19 Laboratory Exercise 2

CMOS VLSI DesignIntroductionSlide 20 Laboratory Exercise 3

CMOS VLSI DesignIntroductionSlide 21 Need for transistors  Cannot make logic gates with voltage/current source, RLC components –Consider steady state behavior of L and C  Need a “switch”: something where a (small) signal can control the flow of another signal

CMOS VLSI DesignIntroductionSlide 22 Coherers and Triodes  Hertz: spark gap transmitter, detector –Verified Maxwell’s equations –Not practical Tx/Rx system  Marconi: “coherer” changes resistance after EM pulse, connects to solenoid  Triode: based on Edison’s bulbs! See Ch. 1, Tom Lee, “Design of CMOS RF ICs”

CMOS VLSI DesignIntroductionSlide 23 A Brief History of MOS Some of the events which led to the microprocessor Photographs from “State of the Art: A photographic history of the integrated circuit,” Augarten, Ticknor & Fields, They can also be viewed on the Smithsonian web site,

CMOS VLSI DesignIntroductionSlide 24 Lilienfeld patents 1930: “Method and apparatus for controlling electric currents”, U.S. Patent 1,745, : “Device for controlling electric current”, U. S. Patent 1,900,018

CMOS VLSI DesignIntroductionSlide 25 Bell Labs  1940: Ohl develops the PN Junction  1945: Shockley's laboratory established  1947: Bardeen and Brattain create point contact transistor (U.S. Patent 2,524,035) Diagram from patent application

CMOS VLSI DesignIntroductionSlide 26 Bell Labs  1951: Shockley develops a junction transistor manufacturable in quantity ( U.S. Patent 2,623,105 ) Diagram from patent application

CMOS VLSI DesignIntroductionSlide s – Silicon Valley  1950s: Shockley in Silicon Valley  1955: Noyce joins Shockley Laboratories  1954: The first transistor radio  1957: Noyce leaves Shockley Labs to form Fairchild with Jean Hoerni and Gordon Moore  1958: Hoerni invents technique for diffusing impurities into Si to build planar transistors using a SiO 2 insulator  1959: Noyce develops first true IC using planar transistors, back-to-back PN junctions for isolation, diode-isolated Si resistors and SiO 2 insulation with evaporated metal wiring on top

CMOS VLSI DesignIntroductionSlide 28 The Integrated Circuit  1959: Jack Kilby, working at TI, dreams up the idea of a monolithic “integrated circuit” –Components connected by hand-soldered wires and isolated by “shaping”, PN-diodes used as resistors (U.S. Patent 3,138,743) Diagram from patent application

CMOS VLSI DesignIntroductionSlide 29 Integrated Circuits  1961: TI and Fairchild introduce the first logic ICs ($50 in quantity)  1962: RCA develops the first MOS transistor RCA 16-transistor MOSFET ICFairchild bipolar RTL Flip-Flop

CMOS VLSI DesignIntroductionSlide 30 Computer-Aided Design  1967: Fairchild develops the “Micromosaic” IC using CAD –Final Al layer of interconnect could be customized for different applications  1968: Noyce, Moore leave Fairchild, start Intel

CMOS VLSI DesignIntroductionSlide 31 RAMs  1970: Fairchild introduces 256-bit Static RAMs  1970: Intel starts selling1K-bit Dynamic RAMs Fairchild bit SRAMIntel K-bit DRAM

CMOS VLSI DesignIntroductionSlide 32 The Microprocessor  1971: Intel introduces the 4004 –General purpose programmable computer instead of custom chip for Japanese calculator company