Digital IC2.ppt vlsi ic circuit design and structure
- 1. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Introduction to VLSI Design Instructor: Steven P. Levitan levitan@ee.pitt.edu TA: Jeremiah Cessna jecst40@pitt.edu Book: Digital Integrated Circuits: A Design Perspective; Jan Rabaey Lab Notes: at Copycat http://kona.ee.pitt.edu/steve/EE1192 http://infopad.EECS.Berkeley.EDU/~icdesign/
- 2. Jan M. Rabaey Digital Integrated Circuits A Design Perspective
- 3. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Course Outline (approximate) – Introduction and Motivation – The VLSI Design Process – Details of the MOS Transistor – Device Fabrication – Design Rules – CMOS circuits – VLSI Structures – System Timing – Real Circuits and Performance
- 4. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Reference Books – Principles of CMOS VLSI Design: Neil Weste and Kamran Eshraghian – CMOS: Baker, Li, Boyce – Application Specific Integrated Circuits: Smith – The Design and Analysis of VLSI – Circuits: Lance Glasser and Daniel Dobberpuhl – Introduction to VLSI Systems: Carver Mead & Lynn Conway – NewsGroups: comp.lsi, comp.lsi.cad
- 5. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Software – Magic Unix Based Interactive Design Rule Checking Circuit Extraction Supported Technology files – Spice Well known and disliked Spice 3 allows user models Good support/documentation Interface with Magic extraction – Irsim Switch / Switched - Resistor level Fast functional validation Good interface with Magic
- 6. The First Computer The Babbage Difference Engine (1832) 25,000 parts cost: £17,470 Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 7. ENIAC - The first electronic computer (1946) Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 8. Evolution in Complexity Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 9. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction What is “CMOS VLSI”? – MOS = Metal Oxide Semiconductor (This used to mean a Metal gate over Oxide insulation) – Now we use polycrystalline silicon which is deposited on the surface of the chip as a gate. We call this “poly” or just “red stuff” to distinguish it from the body of the chip, the substrate, which is a single crystal of silicon. – We do use metal (aluminum) for interconnection wires on the surface of the chip.
- 10. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction CMOS:Complementary MOS – Means we are using both N-channel and P- channel type enhancement mode Field Effect Transistors (FETs). – Field Effect- NO current from the controlling electrode into the output FET is a voltage controlled current device BJT is a current controlled current device – N/P Channel - doping of the substrate for increased carriers (electrons or holes)
- 11. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction N-Channel Enhancement mode MOS FET – Four Terminal Device - substrate bias –The “self aligned gate” - key to CMOS
- 12. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction VLSI:Very Large Scale Integration Integration: Integrated Circuits » multiple devices on one substrate How large is Very Large? – SSI (small scale integration) 7400 series, 10-100 transistors – MSI (medium scale) 74000 series 100-1000 – LSI 1,000-10,000 transistors – VLSI > 10,000 transistors – ULSI/SLSI (some disagreement)
- 13. Intel 4004 Micro-Processor Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 14. Evolution in Transistor Count Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 15. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Scale Example Consider a chip size of 20mm X 20mm Consider a transistor size of 2um X 2um » With area for wires, etc. 1x108 transistors / chip Or - plot at 1 transistor : 1 mm – 1 chip : 20 meter x 20 meter plot
- 16. Intel Pentium (II) microprocessor Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 17. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction VLSI Design – But the real issue is that VLSI is about designing systems on chips. – The designs are complex, and we need to use structured design techniques and sophisticated design tools to manage the complexity of the design. – We also accept the fact that any technology we learn the details of will be out of date soon. – We are trying to develop and use techniques that will transcend the technology, but still respect it.
- 18. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction The Process of VLSI Design: Consists of many different representations/Abstractions of the system (chip) that is being designed. – System Level Design – Architecture / Algorithm Level Design – Digital System Level Design – Logical Level Design – Electrical Level Design – Layout Level Design – Semiconductor Level Design (possibly more) Each abstraction/view is itself a Design Hierarchy of refinements which decompose the design.
- 19. Design Abstraction Levels n+ n+ S G D + DEVICE CIRCUIT GATE MODULE SYSTEM Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 20. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Help from Computer Aided Design tools Tools » Editors » Simulators » Libraries » Module Synthesis » Place/Route » Chip Assemblers » Silicon Compilers Experts » Logic design » Electronic/circuit design » Device physics » Artwork » Applications - system design » Architectures
- 21. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction New Design Methodologies Methodologies which are based on: » System Level Abstractions v.s. Device Characteristic Abstractions – Logic structures and circuitry change slowly over time trade-offs do change, but the choices do not » Scalable Designs – Layout techniques also change slowly. But the minimum feature size steadily decreases with time (also Voltage, Die Size, etc.)
- 22. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Design Approaches – Custom full control of design best results, slowest design time. – Semi-custom (std cell) use Cell libraries from vendor cad tools, faster design time – Gate Array fastest design time worst speed/power/density best low volume (worst high volume) – EPLA/EPLD - FPGA - electrically programmable (in the field) -
- 23. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Close up of Intel Chip? Time Magazine, July 1998
- 24. Evolution in Speed/Performance Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 25. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction Technologies – Bipolar (BJT) TTL, Schottky ECL I^2 L – Dual Junction, current controlled devices MOS (FET unipolar) » NMOS, PMOS » CMOS <== our course – Single Junction voltage controlled devices GaAs (typically JFET’s) OEIC’s - MQW’s, Integrated Lasers,?
- 26. Silicon in 2010 Die Area: 2.5x2.5 cm Voltage: 0.6 V Technology: 0.07 m Dens ity Acces sTime (Gbits /cm2) (ns ) DRAM 8.5 10 DRAM (Logic) 2.5 10 SRAM (Cache) 0.3 1.5 Dens ity Max. Ave. Power Clock Rate (Mgates /cm2) (W /cm2) (GHz) Cus tom 25 54 3 Std. Cell 10 27 1.5 GateArray 5 18 1 Single-Mas k GA 2.5 12.5 0.7 FPGA 0.4 4.5 0.25 Digital Integrated Circuits © Prentice Hall 1995 Introduction
- 27. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction SIA -National Technology Roadmap for Semiconductors
- 28. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction SIA -National Technology Roadmap for Semiconductors 8 inch 18 inch
- 29. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction SIA -National Technology Roadmap for Semiconductors
- 30. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction SIA -National Technology Roadmap for Semiconductors
- 31. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction SIA -National Technology Roadmap for Semiconductors
- 32. Introduction to VLSI Design © Steven P. Levitan 1998 Introduction SIA -National Technology Roadmap for Semiconductors