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8 Bit Gray Code Converter

Rasha ShabaHala ShabaKai Homidi

Advisor: David ParentDATE 12/06/04

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Agenda

• Abstract• Introduction

– Why– Simple Theory– Back Ground information

• Project (Experimental) Details• Verifications of Results• Lessons Learned• Summary

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Abstract

• We designed an 8-bit gray code converter according to the following specifications.

Frequency: 200 MHz. Power: <25mW Area: <800mx800m

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Introduction• We chose a gray code converter for our project

because It is applied in a broad range of applications It incorporates all principles taught in

EE-166

• The basic theory of our project is to convert a series of binary numbers to gray code numbers with the use of XOR gates

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The Gray Code

• Natural Binary Gray Code • 0 0000 0000 • 1 0001 0001

• 2 0010 0011

• 3 0011 0010

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Project Details

• The Gray Code Converter consists of the following:NAND gatesXOR gatesD Flip Flops

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NAND Gate

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NAND

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XOR Gate

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XOR

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XOR

XOR

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DFF

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DFF

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Longest Path CalculationsLogic Level

Gate Cg to Drive

#CDNs #CDPs #LNs #LPs WN (H.C)

WP (H.C)

WN (S)

WP (S)

WN (L)

WP (L)

Cg of gate

1 NAND3 20 5 3 3 1 1.10 0.63 1.5 1.5 1.5 1.5 5.10 2 NAND3 5.10 5 3 3 1 0.54 0.31 1.5 1.5 1.5 1.5 5.10 3 INV 5.10 1 1 1 1 0.07 0.10 1.5 1.5 1.5 1.5 5.10 4 NOR 5.10 4 6 2 2 0.49 0.83 1.5 1.5 1.5 1.5 5.10 5 NOR 5.10 4 6 2 2 0.49 0.83 1.5 1.5 1.5 1.5 5.10 6 INV 5.10 1 1 1 1 0.07 0.10 1.5 1.5 1.5 1.5 5.10 7 NAND3 5.10 5 3 3 1 0.54 0.31 1.5 1.5 1.5 1.5 5.10 8 NAND3 5.10 5 3 3 1 0.54 0.31 1.5 1.5 1.5 1.5 5.10

nsns

PHL 625.8

5 Note: All widths are in microns

and capacitances in fF

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Gray Code Converter Schematic

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Gray Code Converter Layout

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Verification (LVS)

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Input Data Output Data

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Verification of Specifications

Frequency: 200 MHz Power: 5mW Area: 178mx555m Logic: Functional

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Lessons Learned

• Advice to EE-166 students:Start earlyConsult with Professor Parent in office hoursPay attention to lectureThink of the project as a learning experience

• Advice to EE-166 professors:Narrow down class notes to more useful

examples

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Summary

• The gray code converter project was worthwhile because it firmly illustrated the principles taught in EE-166 course

• The main results of the project are the following Timing specifications were met The basic principles of design and layout of CMOS

technology were learned

• Gray code converters will continue to be a main components in may systems to come

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Acknowledgements

• Thanks to Hala, Kai, & Rasha for putting up with us.

• Thanks to Cadence Design Systems for the VLSI lab

• Thanks to Synopsys for Software donation

• Professor David Parent