intro (1).ppt

intro (1).ppt

• 1.
  CSCE 613: Fundamentalsof VLSI Chip Design Instructor: Jason D. Bakos
• 2.
  Fund. of VLSIChip Design 2 VLSI Design • What is VLSI? – “Very Large Scale Integration” – Defines integration level – 1980s hold-over from outdated taxonomy for integration levels • Obviously influenced from frequency bands, i.e. HF, VHF, UHF – Sources disagree on what is measured (gates or transistors?) • SSI – Small-Scale Integration (0-102) • MSI – Medium-Scale Integration (102-103) • LSI – Large-Scale Integration (103-105) • VLSI – Very Large-Scale Integration (105-107) • ULSI – Ultra Large-Scale Integration (>=107)
• 3.
  Fund. of VLSIChip Design 3 Integration Level Trends Obligatory historical Moore’s law plot
• 4.
  Fund. of VLSIChip Design 4 Integrated Circuits/MEMs • Today, VLSI refers to systems impl. w/integrated circuits – Integrated circuit refers mostly to general manufacturing technique • micro/nano-scale devices on a semiconductor (crystalline) substrate • Formed using chemical/lithography processing • What kind of devices / structures? – transistors (bipolar, MOSFET) – wires (interconnects and passive devices) – diodes (junction, LEDs, VCSELs, MSM, photoconductor, PiN) – MEMs (integration of piezoelectrics and mechanics based on static electrical fields: accelerometers, gyroscopes, pressure sensors, micro-mirrors) • For CMOS digital design, we only use MOSFET transistors (used as switches) and wires
• 5.
  Fund. of VLSIChip Design 5 Chips • Integrated circuits consist of: – A small square or rectangular “die”, < 1mm thick • Small die: 1.5 mm x 1.5 mm => 2.25 mm2 • Large die: 15 mm x 15 mm => 225 mm2 – Larger die sizes mean: • More logic, memory • Less volume • Less yield – Dies are made from silicon (substrate) • Substrate provides mechanical support and electrical common point
• 6.
  Fund. of VLSIChip Design 6 VLSI Design • Draw polygons that represent layers deposited-on or infused-into the substrate – More of an art than science • One 2-input NAND gate with 4 transistors • Typical microprocessor contains 50 – 200 million transistors (10-50 million gates) Scale: approximately 10 um x 10 um
• 7.
  Fund. of VLSIChip Design 7 VLSI Design • Manual layout design is obviously not practical • Design complexity: – Manually drawing layout for a billion transistors would take too long – Even if we could… • How to verify (test) designs for functionality, speed, power, etc.? – Complexity scales faster than actual design • How to reuse designs? • How to create human-readable designs? • How to speed-up design process? • These problems form a great deal of work – Electronic Design Automation (EDA) – a.k.a. CAD • Advancing EDA technology, fabrication technology, designs and microarchitectures, and IP form bulk of work (and money) in the industry
• 8.
  Fund. of VLSIChip Design 8 EDA Tools • Conclusion: – This course is about using design tools to manage design complexity of VLSI systems – Only way to learn tools: practice and work with tools individually – Must teach IC fundamentals, but prevent course from becoming semiconductor theory, analog electronics, circuits, or digital logic course • Target large-scale integration and EDA • Reach good balance between fundamental IC theory and automated large- scale design methodology • 80-90% of course time will be spent in lab – Tutorials will provide basic knowledge – Must learn the tools on your own (assisted by instructor)
• 9.
  Fund. of VLSIChip Design 9 Course Overview • This course is called “Fundamentals of VLSI Chip Design” • Focus on large-scale system design (CAD tools) • CAD tools manage design and verification complexity • What we have… – Latest, most advanced CAD tools in the EDA industry – Three primary players • Synopsys, #258 ($1.2 billion revenue) • Cadence Design Systems, #259 ($1.1 billion revenue) • Mentor Graphics, ? • Comparison: Microsoft #95 ($36.8 billion), Intel #102 ($34.2 billion) – Fabrication award for 500 nm CMOS fabrication process • AMI C5N process with academic design kit (NCSU CDK) • 1.5 mm x 1.5 mm die size, multiple dies, packaging
• 10.
  Fund. of VLSIChip Design 10 EDA Tools • Big companies, lots of money, 40 years of integrated circuit design experience, conferences, journals, powerful PCs… what’s the problem? • IC CAD tools are difficult to use – Written by electrical engineers (not professional programmers) – Incredibly buggy – Not documented – Rely on ancient, outdated file formats for interoperability – Still mostly rely on command-line interfaces – Utilize outdated, primitive, buggy APIs for GUIs – Inherently required to solve hard problems • Place components, route wires • Must utilize advanced heuristics that are only as good as fabrication process technology information and user input (garbage-in, garbage-out)
• 11.
  Fund. of VLSIChip Design 11 EDA Tools • Cadence tools – “IC-Tools” => IC5141 package (Linux) – Collection of tools managed by Design Framework II (dfII) • Virtuoso schematic/layout editor • Analog Environment • Spectre simulator • Diva DRC, EXT, LVS • Other Cadence tools – SignalStorm => TSI42 package (Linux) – Abstract Generator => DSMSE54 (Solaris) – First Encounter => SOC42 package (Linux) • Synopsys – Design Compiler (Linux) • Mentor – HDL Designer (Linux)
• 12.
  Fund. of VLSIChip Design 12 What EDA Tools Can Do • Manual layout vs. EDA is like: – Manual transmission vs. automatic transmission – HTML programming vs. Frontpage – Assembly code programming vs. compiled high-level language • Manual layout for small, optimized designs will always be superior • EDA techniques for larger-scale designs will always be superior (verification, reusability, NRE, etc.) • Goal: do careful, manual design of smaller components (cells) and use EDA to combine them for large-scale design
• 13.
  Fund. of VLSIChip Design 13 What EDA Tools Can Do • “My” Design Flow Digital cell library design Cadence IC-Tools Circuit Sim Cadence IC-Tools Characterization Cadence SignalStorm Abstract Generation Cadence AbGen Standard Cell Library Behavioral VHDL Design Mentor HDL Designer Design Specification char. info process info, cell abstracts Synthesis Synopsys Design Analyzer VHDL Behavioral Simulation Mentor ModelSim Place-and-Route Cadence First Encounter Cell Timing Simulation Mentor ModelSim Verilog Interconnect Timing Simulation Mentor ModelSim
• 14.
  Fund. of VLSIChip Design 14 Course Organization • Course will be divided into units – Introduction: IC design and fabrication fundamentals • Lectures • Assignments from textbook – CMOS circuit design, layout, and simulation • Tutorial: Cadence IC-Tools • Design projects • Development of standard cell library – Cell library development • Tutorial: Cadence SignalStorm and Abstract Generator • Report on cell library – VHDL Design • Lectures on VHDL • Tutorial: Mentor HDL Designer • Design project – Logic Synthesis • Tutorial: Synopsys Design Analyzer – Place-and-route • Tutorial: Cadence First Encounter – Course project • Teams • Design • Fabrication?