FPGA Development

6.

Timing Constraints and Analysis

6.1.

Core Timing Concepts

6.1.1.

The Clock Signal

6.1.1.1.

6.1.1.1.1.

Crystal Oscillators

6.1.1.1.2.

Phase-Locked Loops

6.1.1.1.3.

External Clock Sources

6.1.1.2.

Clock Distribution

6.1.1.2.1.

6.1.1.2.2.

6.1.1.2.3.

6.1.2.

Propagation Delay

6.1.2.1.

6.1.2.2.

Interconnect Delay

6.1.2.3.

Temperature and Voltage Effects

6.1.3.

6.1.3.1.

Definition and Importance

6.1.3.2.

Setup Time Violations

6.1.4.

6.1.4.1.

Definition and Importance

6.1.4.2.

Hold Time Violations

6.1.5.

Clock-to-Output Delay

6.1.6.

6.1.6.1.

6.1.6.2.

Process Variations

6.2.

6.2.1.

6.2.1.1.

Register-to-Register Paths

6.2.1.2.

Input-to-Register Paths

6.2.1.3.

Register-to-Output Paths

6.2.1.4.

Input-to-Output Paths

6.2.2.

6.2.2.1.

Clock Source to Register

6.2.2.2.

Clock Distribution Networks

6.2.3.

Asynchronous Paths

6.2.3.1.

6.2.3.2.

Asynchronous Inputs

6.3.

Static Timing Analysis

6.3.1.

STA Fundamentals

6.3.2.

Timing Graph Construction

6.3.3.

Path Delay Calculation

6.3.4.

Slack Calculation

6.3.4.1.

6.3.4.2.

6.3.5.

Critical Path Analysis

6.3.5.1.

Identifying Critical Paths

6.3.5.2.

6.3.6.

Timing Violations

6.3.6.1.

Setup Violations

6.3.6.2.

Hold Violations

6.3.6.3.

Recovery Violations

6.3.6.4.

Removal Violations

6.3.7.

Multi-Corner Analysis

6.3.7.1.

Process Corners

6.3.7.2.

Temperature Variations

6.3.7.3.

Voltage Variations

6.4.

Design Constraints

6.4.1.

Timing Constraints Files

6.4.1.1.

6.4.1.2.

6.4.1.3.

TCL-Based Constraints

6.4.2.

Clock Constraints

6.4.2.1.

Primary Clock Definition

6.4.2.2.

Generated Clock Definition

6.4.2.3.

6.4.2.4.

6.4.2.5.

Clock Uncertainty

6.4.3.

I/O Constraints

6.4.3.1.

Input Delay Constraints

6.4.3.2.

Output Delay Constraints

6.4.3.3.

6.4.4.

Path Constraints

6.4.4.1.

False Path Constraints

6.4.4.2.

Multicycle Path Constraints

6.4.4.3.

Maximum Delay Constraints

6.4.4.4.

Minimum Delay Constraints

6.4.5.

Physical Constraints

6.4.5.1.

Location Constraints

6.4.5.2.

Area Constraints

6.4.5.3.

Floorplanning Constraints

6.5.

Clock Domain Crossing

6.5.1.

6.5.1.1.

Causes of Metastability

6.5.1.2.

MTBF Calculations

6.5.2.

Synchronization Techniques

6.5.2.1.

Two-Flip-Flop Synchronizers

6.5.2.2.

Multi-Flip-Flop Synchronizers

6.5.3.

Asynchronous FIFO Design

6.5.3.1.

Gray Code Counters

6.5.3.2.

Empty and Full Flag Generation

6.5.4.

Handshake Protocols

6.5.4.1.

Request-Acknowledge Protocols

6.5.4.2.

Pulse Synchronizers

6.5.5.

CDC Verification

6.5.5.1.

CDC Checking Tools

6.5.5.2.

Simulation Techniques

6.6.

Achieving Timing Closure

6.6.1.

Analyzing Timing Reports

6.6.1.1.

Understanding Slack Reports

6.6.1.2.

Path Detail Analysis

6.6.1.3.

Constraint Coverage

6.6.2.

Design Techniques for Performance

6.6.2.1.

6.6.2.1.1.

Pipeline Stages

6.6.2.1.2.

Pipeline Balancing

6.6.2.1.3.

Pipeline Hazards

6.6.2.2.

6.6.2.2.1.

Register Movement

6.6.2.2.2.

Automatic Retiming

6.6.2.3.

Logic Replication

6.6.2.3.1.

Fanout Reduction

6.6.2.3.2.

6.6.2.4.

Resource Optimization

6.6.2.4.1.

6.6.2.4.2.

BRAM Utilization

6.6.3.

Implementation Optimization

6.6.3.1.

Placement Optimization

6.6.3.2.

Routing Optimization

6.6.3.3.

Physical Synthesis

6.6.4.

Iterative Design Flow

6.6.4.1.

Synthesis Settings Optimization

6.6.4.2.

Implementation Strategy Selection

6.6.4.3.

Incremental Compilation

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