ELEC 2200-002 Digital Logic Circuits Fall 2014 Logic Synthesis (Chapters 2-5) Vishwani D. Agrawal James J. Danaher Professor Department of Electrical and.

Slides:



Advertisements
Similar presentations
Modern VLSI Design 3e: Chapter 3 Copyright 1998, 2002 Prentice Hall PTR Topics n Combinational logic functions. n Static complementary logic gate structures.
Advertisements

Digital Integrated Circuits© Prentice Hall 1995 Combinational Logic COMBINATIONAL LOGIC.
Logic Gates.
VLSI lecture, 2000 Lecture 4 MOS Circuits Department of Computer Engineering, Prince of Songkla University by Wannarat Suntiamorntut.
10/4-6/05ELEC / Lecture 111 ELEC / (Fall 2005) Special Topics in Electrical Engineering Low-Power Design of Electronic Circuits.
9/15/05ELEC / Lecture 71 ELEC / (Fall 2005) Special Topics in Electrical Engineering Low-Power Design of Electronic Circuits.
Spring 08, Mar 11 ELEC 7770: Advanced VLSI Design (Agrawal) 1 ELEC 7770 Advanced VLSI Design Spring 2008 Zero - Skew Clock Routing Vishwani D. Agrawal.
ELEC Digital Logic Circuits Fall 2008 Logic Minimization (Chapter 3) Vishwani D. Agrawal James J. Danaher Professor Department of Electrical and.
ECE 667 Synthesis and Verification of Digital Systems
Spring 07, Feb 13 ELEC 7770: Advanced VLSI Design (Agrawal) 1 ELEC 7770 Advanced VLSI Design Spring 2007 Binary Decision Diagrams Vishwani D. Agrawal James.
10/25/05ELEC / Lecture 151 ELEC / (Fall 2005) Special Topics in Electrical Engineering Low-Power Design of Electronic Circuits.
Combinational Circuits
4/28/05Vemula: ELEC72501 Enhanced Scan Based Flip-Flop for Delay Testing By Sudheer Vemula.
Spring 08, Jan 15 ELEC 7770: Advanced VLSI Design (Agrawal) 1 ELEC 7770 Advanced VLSI Design Spring 2007 Introduction Vishwani D. Agrawal James J. Danaher.
Technology Mapping.
Spring 07, Jan 16 ELEC 7770: Advanced VLSI Design (Agrawal) 1 ELEC 7770 Advanced VLSI Design Spring 2007 Introduction Vishwani D. Agrawal James J. Danaher.
Copyright Agrawal, 2007 ELEC6270 Fall 07, Lecture 12 1 ELEC 5270/6270 Fall 2007 Low-Power Design of Electronic Circuits Pass Transistor Logic: A Low Power.
Spring 08, Feb 28 ELEC 7770: Advanced VLSI Design (Agrawal) 1 ELEC 7770 Advanced VLSI Design Spring 2008 Retiming Vishwani D. Agrawal James J. Danaher.
10/11/05ELEC / Lecture 121 ELEC / (Fall 2005) Special Topics in Electrical Engineering Low-Power Design of Electronic Circuits.
Fall 2006, Oct. 5 ELEC / Lecture 8 1 ELEC / (Fall 2006) Low-Power Design of Electronic Circuits Glitch-Free ASICs and Custom.
Spring 07, Apr 5 ELEC 7770: Advanced VLSI Design (Agrawal) 1 ELEC 7770 Advanced VLSI Design Spring 2007 Retiming Vishwani D. Agrawal James J. Danaher Professor.
Copyright Agrawal, 2007 ELEC6270 Fall 07, Lecture 13 1 ELEC 5270/6270 Fall 2007 Low-Power Design of Electronic Circuits Pseudo-nMOS, Dynamic CMOS and Domino.
Technology Mapping 1 Outline –What is Technology Mapping? –Rule-Based Mapping –Tree Pattern Matching Goal –Understand technology mapping –Understand mapping.
10/20/05ELEC / Lecture 141 ELEC / (Fall 2005) Special Topics in Electrical Engineering Low-Power Design of Electronic Circuits.
Charles Kime & Thomas Kaminski © 2008 Pearson Education, Inc. (Hyperlinks are active in View Show mode) Chapter 3 – Combinational Logic Design Part 1 –
ECE 331 – Digital System Design Multi-level Logic Circuits and NAND-NAND and NOR-NOR Circuits (Lecture #8) The slides included herein were taken from the.
Technology Mapping Outline Goal What is Technology Mapping?
ECEN 248: INTRODUCTION TO DIGITAL SYSTEMS DESIGN Lecture 5 Dr. Shi Dept. of Electrical and Computer Engineering.
Digital Integrated Circuits© Prentice Hall 1995 Combinational Logic COMBINATIONAL LOGIC.
9/27/05ELEC / Lecture 91 ELEC / (Fall 2005) Special Topics in Electrical Engineering Low-Power Design of Electronic Circuits.
Overview Part 1 – Design Procedure 3-1 Design Procedure
1 VLSI CAD Flow: Logic Synthesis, Lecture 13 by Ajay Joshi (Slides by S. Devadas)
Charles Kime & Thomas Kaminski © 2004 Pearson Education, Inc. Terms of Use (Hyperlinks are active in View Show mode) Terms of Use Lecture 12 – Design Procedure.
Combinational Logic Design BIL- 223 Logic Circuit Design Ege University Department of Computer Engineering.
Charles Kime & Thomas Kaminski © 2008 Pearson Education, Inc. (Hyperlinks are active in View Show mode) Chapter 3 – Combinational Logic Design Part 1 –
ETE 204 – Digital Electronics
Technology Mapping. 2 Technology mapping is the phase of logic synthesis when gates are selected from a technology library to implement the circuit. Technology.
EE 5900 Advanced Algorithms for Robust VLSI CAD, Spring 2009 Combinational Circuits.
ELEC Digital Logic Circuits Fall 2015 Logic Minimization (Chapter 3) Vishwani D. Agrawal James J. Danaher Professor Department of Electrical and.
Static CMOS Logic Seating chart updates
Solid-State Devices & Circuits
CMOS Logic Gates. NMOS transistor acts as a switch 2 When gate voltage is 0 V No channel is formed current does not flow easily “open switch” When gate.
ELEC Digital Logic Circuits Fall 2015 Logic Synthesis (Chapters 2-5) Vishwani D. Agrawal James J. Danaher Professor Department of Electrical and.
ELEC Digital Logic Circuits Fall 2015 Delay and Power Vishwani D. Agrawal James J. Danaher Professor Department of Electrical and Computer Engineering.
ELEC Digital Logic Circuits Fall 2014 Delay and Power Vishwani D. Agrawal James J. Danaher Professor Department of Electrical and Computer Engineering.
ELEC 5270/6270 Spring 2013 Low-Power Design of Electronic Circuits Pass Transistor Logic: A Low Power Logic Family Vishwani D. Agrawal James J. Danaher.
Lecture 7 Multi-Level Gate Networks
ELEC Digital Logic Circuits Fall 2014 Logic Minimization (Chapter 3)
ELEC 7770 Advanced VLSI Design Spring 2016 Introduction
ELEC 5270/6270 Spring 2013 Low-Power Design of Electronic Circuits Pseudo-nMOS, Dynamic CMOS and Domino CMOS Logic Vishwani D. Agrawal James J. Danaher.
ELEC 7770 Advanced VLSI Design Spring 2014 Introduction
Chapter 12 : Field – Effect Transistors
ELEC 5270/6270 Spring 2015 Low-Power Design of Electronic Circuits Pseudo-nMOS, Dynamic CMOS and Domino CMOS Logic Vishwani D. Agrawal James J. Danaher.
ELEC 7770 Advanced VLSI Design Spring 2012 Retiming
ELEC 7770 Advanced VLSI Design Spring 2012 Introduction
ELEC 7770 Advanced VLSI Design Spring 2010 Introduction
CSE 370 – Winter Combinational Implementation - 1
ELEC 5270/6270 Spring 2011 Low-Power Design of Electronic Circuits Pass Transistor Logic: A Low Power Logic Family Vishwani D. Agrawal James J. Danaher.
ELEC 7770 Advanced VLSI Design Spring 2014 Technology Mapping
ELEC 7770 Advanced VLSI Design Spring 2016 Technology Mapping
ECE 667 Synthesis and Verification of Digital Systems
Combinational Circuits
Technology Mapping I based on tree covering
VLSI CAD Flow: Logic Synthesis, Placement and Routing Lecture 5
ELEC 7770 Advanced VLSI Design Spring 2016 Retiming
ELEC Digital Logic Circuits Fall 2015 Logic Testing (Chapter 12)
Combinational Circuits
*Internal Synthesizer Flow *Details of Synthesis Steps
ELEC 5270/6270 Spring 2009 Low-Power Design of Electronic Circuits Pseudo-nMOS, Dynamic CMOS and Domino CMOS Logic Vishwani D. Agrawal James J. Danaher.
Presentation transcript:

ELEC Digital Logic Circuits Fall 2014 Logic Synthesis (Chapters 2-5) Vishwani D. Agrawal James J. Danaher Professor Department of Electrical and Computer Engineering Auburn University, Auburn, AL Fall 2014, Nov 3... ELEC Lecture 6 1

Logic Synthesis Definition: To design a logic circuit such that it meets the specifications and can be economically manufactured: Performance – meets delay specification, or has minimum delay. Cost – uses minimum hardware, smallest chip area, smallest number of gates or transistors. Power – meets power specification, or consumes minimum power. Testablility – has no redundant (untestable) logic and is easily testable. Fall 2014, Nov 3... ELEC Lecture 6 2

Synthesis Procedure Minimization – Obtain MSOP or MPOS. This is also known as two-level minimization because the result can be implemented as a two-level AND-OR or NAND-NAND or NOR-NOR circuit. Technology mapping – Considering design requirements, transform the minimized form into one of the technologically realizable forms: Programmable logic array (PLA) Standard cell library Field programmable gate array (FPGA) Others... Fall 2014, Nov 3... ELEC Lecture 6 3

References on Synthesis G. De Micheli, Synthesis and Optimization of Digital Circuits, New York: McGraw-Hill, S. Devadas, A. Ghosh and K. Keutzer, Logic Synthesis, New York: McGraw-Hill, Fall 2014, Nov 3... ELEC Lecture 6 4

Programmable Logic Array (PLA) A direct implementation of multi-output function as a two-level circuit in MOS technology. PLA styles: NAND-NAND NOR-NOR Textbook, Chapter 5. Fall 2014, Nov 3... ELEC Lecture 6 5

Example: Two-Output Function Need four products: P1, P2, P3, P4 Fall 2014, Nov 3... ELEC Lecture 6 6 F1 A B C D F2 A B C D

Two-Level AND-OR Implementation Also known as technology-independent circuit. Fall 2014, Nov 3... ELEC Lecture 6 7 A B C D F1 F2 P1 P2 P3 P4 INPUTSANDOR

INPUTSNAND NAND-NAND Implementation Fall 2014, Nov 3... ELEC Lecture 6 8 A B C D F1 F2

A NAND Gate in nMOS Technology Fall 2014, Nov 3... ELEC Lecture 6 9 VDD X Y XY GND VDD X Y XY GND VDD X Y XY GND R. C. Jaeger and T, N. Blalock, Microelectronic Circuit Design, Boston: McGraw-Hill, 2008, Section Depletion load Enhancement load

NAND-NAND PLA Fall 2014, Nov 3... ELEC Lecture 6 10 ABCD F1F2 VDD GND

NAND-NAND PLA SCHEMATIC Fall 2014, Nov 3... ELEC Lecture 6 11 ABCDF1F2 INPUTS OUTPUTS AND-plane OR-plane Transistors at cross-points

Standard-Cell Design Obtain two-level minimized form. Map the design onto predesigned building blocks called standard cells (technology mapping). Standard-cell library contains predesigned logic cells in the technology of manufacture. Examples of technology: 90 nanometer CMOS 65 nanometer CMOS 45 nanometer CMOS... This is known as application-specific integrated circuit (ASIC). Fall 2014, Nov 3... ELEC Lecture 6 12

Technology Mapping Find a common logic element, e.g., two-input NAND gate or inverter (one-input NAND). MSOP is converted into NAND-NAND circuit. Split larger input gates into two-input NAND gates and inverters. Cover the circuit with standard cells, also split into two-input NAND gates and inverters (graph-matching). Fall 2014, Nov 3... ELEC Lecture 6 13

A Typical Cell Library NameArea units (cost)InputsOutput function, Z Inverter2A NAND23A, B NAND34A, B, C NAND45A, B, C, D AOI214A, B, C OAI214A, B, C AOI225A, B, C, D XOR4A, B Fall 2014, Nov 3... ELEC Lecture 6 14 S. Devadas, A. Ghosh and K. Keutzer, Logic Synthesis, New York: McGraw-Hill 1994, Section 7.7, pp

NAND3 Cell in Transistors Fall 2014, Nov 3... ELEC Lecture 6 15 ABCABC Z VDD GND

NAND3 Cell Graphs Fall 2014, Nov 3... ELEC Lecture 6 16 Directed Acyclic Graph (DAG) (tree)

NAND4 Cell Fall 2014, Nov 3... ELEC Lecture 6 17

AOI21 Cell Fall 2014, Nov 3... ELEC Lecture 6 18

OAI21 Cell Fall 2014, Nov 3... ELEC Lecture 6 19

AOI22 Cell in Transistors Fall 2014, Nov 3... ELEC Lecture 6 20 ABCDABCD VDD GND Z Observe that in a CMOS circuit, any vector of input variables connects the output Z either to GND or to VDD, giving it a value 0 or 1, respectively. Examiningthe pull-down network, we notice that the output is connected to GND if AB = 1 or CD =1. That gives the output function as,. The cell, therefore, is AOI22.

AOI22 Cell Fall 2014, Nov 3... ELEC Lecture 6 21

XOR Cell Fall 2014, Nov 3... ELEC Lecture 6 22

Technology Mapping Procedure Obtain MSOP. Convert to two-level AND-OR circuit. Transform to two-level NAND-NAND circuit. Transform to two-input NAND and inverter tree network. Perform an optimal pattern matching to obtain a minimum cost tree covering. Fall 2014, Nov 3... ELEC Lecture 6 23

INPUTSNAND Previous Example: 2-Level NAND Fall 2014, Nov 3... ELEC Lecture 6 24 A B C D F1 F2

A Simple Technology Mapping Fall 2014, Nov 3... ELEC Lecture 6 25 B C F1 F2 D A Cost = 24 NAND2 (3) NAND3 (4) (2) NAND2 (3)

Circuit is a Directed Acyclic Graph (DAG) Fall 2014, Nov 3... ELEC Lecture 6 26 A B C D F1 F2 Each node is a NAND gate.

Splitting into a Forest of Trees Fall 2014, Nov 3... ELEC Lecture 6 27 A B C D F1 F2 C B D D A

Splitting DAG into Trees (Forest) Fall 2014, Nov 3... ELEC Lecture 6 28 A B C D F1 F2 D C B A D

Two-Input NAND Trees Fall 2014, Nov 3... ELEC Lecture 6 29 A B C D F1 F2 C B D D A

Alternatively, in Graph Format Fall 2014, Nov 3... ELEC Lecture 6 30 A B C D F1 F2 C B D D A

An Improved Technology Mapping Fall 2014, Nov 3... ELEC Lecture 6 31 A B C D F1 F2 C B D D A OAI21 (4) NAND3 (4) NAND2 (3) (2) Cost = 22 Inverters inserted For pattern matching (2)

Alternatively, in Graph Format Fall 2014, Nov 3... ELEC Lecture 6 32 A B C D F1 F2 C B D D A NAND3 (4) OAI21 (4) NAND2 (3) (2) Cost = 22 Nodes inserted For pattern matching

Improved Technology Mapping Fall 2014, Nov 3... ELEC Lecture 6 33 B C F1 F2 D A Cost = 22 NAND2 (3) NAND3 (4) (2) NAND2 (3) AOI21 (4)

Original Reference K. Keutzer, “DAGON: Technology Binding and Local Optimization by DAG matching,” Proc. 24th Design Automation Conf., 1987, pp Fall 2014, Nov 3... ELEC Lecture 6 34