Contents

Preface

What's New

Typographic and Syntax Conventions

1

LEF Syntax

About Library Exchange Format Files

General Rules

Character Information

Managing LEF Files

Order of LEF Statements

LEF Statement Definitions

Bus Bit Characters

Clearance Measure

Divider Character

Extensions

FIXEDMASK

Layer (Cut)

Layer (Implant)

Layer (Masterslice or Overlap)

Layer (Routing)

Library

Macro

Manufacturing Grid

Maximum Via Stack

Nondefault Rule

Property Definitions

Site

Units

Use Min Spacing

Version

Via

Via Rule

Via Rule Generate

2

ALIAS Statements

ALIAS Statements

ALIAS Definition

ALIAS Examples

ALIAS Expansion

3

Working with LEF

Incremental LEF

Error Checking

Message Facility

Error-Checking Facility

4

DEF Syntax

About Design Exchange Format Files

General Rules

Character Information

Order of DEF Statements

DEF Statement Definitions

Blockages

Bus Bit Characters

Component Mask Shift

Components

Design

Die Area

Divider Character

Extensions

Fills

GCell Grid

Groups

History

Nets

Nondefault Rules

Pins

Pin Properties

Property Definitions

Regions

Rows

Scan Chains

Slots

Special Nets

Styles

Technology

Tracks

Units

Version

Vias

A

Examples

LEF

DEF

Scan Chain Synthesis Example

B

Optimizing LEF Technology for Place and Route

Overview

Guidelines for Routing Pitch

Guidelines for Wide Metal Spacing

Guidelines for Wire Extension at Vias

Guidelines for Default Vias

Guidelines for Stack Vias (MAR Vias) and Samenet Spacing

Example of an Optimized LEF Technology File

C

Calculating and Fixing Process Antenna Violations

Overview

What Are Process Antennas?

What Is the Process Antenna Effect (PAE)?

What Is the Antenna Ratio?

What Can Be Done to Improve the Antenna Ratio?

Using Process Antenna Keywords in the LEF and DEF Files

Calculating Antenna Ratios

Calculating the Antenna Area

Calculating a PAR

Calculating a CAR

Calculating Ratios for a Cut Layer

Checking for Antenna Violations

Area Ratio Check

Side Area Ratio Check

Cumulative Area Ratio Check

Cumulative Side Area Ratio Check

Cut Layer Process Antenna Model Examples

Routing Layer Process Antenna Model Examples

Example Using the Antenna Keywords

Using Antenna Diode Cells

Changing the Routing

Inserting Antenna Diode Cells

Using DiffUseOnly

Calculations for Hierarchical Designs

LEF and DEF Keywords for Hierarchical Designs

Design Example

Top-Down Hierarchical Design Example

Index