Intel® Quartus® Prime Standard Edition User Guide: Power Analysis and Optimization

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ID 683506
Date 9/24/2018
Public
Document Table of Contents
Document Table of Contents x
1. Power Analysis 2. Power Optimization A. Intel® Quartus® Prime Standard Edition User Guides
1. Power Analysis x
1.1. Comparison of the EPE and the Intel® Quartus® Prime Power Analyzer 1.2. Power Estimations and Design Requirements 1.3. Power Analyzer Walkthrough 1.4. Inputs for the Power Analyzer 1.5. Power Analysis in Modular Design Flows 1.6. Power Analyzer Compilation Report 1.7. Scripting Support 1.8. Power Analysis Revision History
1.4. Inputs for the Power Analyzer x
1.4.1. Operating Settings and Conditions 1.4.2. Sources for Signal Activity Data
1.4.2. Sources for Signal Activity Data x
1.4.2.1. Waveforms from Supported Simulators 1.4.2.2. .vcd Files from Third-Party Simulation Tools 1.4.2.3. Signal Activities from RTL (Functional) Simulation, Supplemented by Vectorless Estimation 1.4.2.4. Signal Activities from Vectorless Estimation and User-Supplied Input Pin Activities 1.4.2.5. Signal Activities from User Defaults Only
1.4.2.2. .vcd Files from Third-Party Simulation Tools x
1.4.2.2.1. Generating a .vcd in a EDA Simulation Tool 1.4.2.2.2. Generating a .vcd from ModelSim® Software
1.4.2.3. Signal Activities from RTL (Functional) Simulation, Supplemented by Vectorless Estimation x
1.4.2.3.1. RTL Simulation Limitation
1.5. Power Analysis in Modular Design Flows x
1.5.1. Complete Design Simulation 1.5.2. Modular Design Simulation 1.5.3. Multiple Simulations on the Same Entity 1.5.4. Overlapping Simulations 1.5.5. Partial Simulations 1.5.6. Node Name Matching Considerations 1.5.7. Glitch Filtering 1.5.8. Node and Entity Assignments 1.5.9. Default Toggle Rate Assignment 1.5.10. Vectorless Estimation
1.5.5. Partial Simulations x
1.5.5.1. Specifying Start and End Time when Performing Signal-Activity Calculations using the Limit VCD Period Option
1.5.7. Glitch Filtering x
1.5.7.1. Enabling Tool Based Glitch Filtering 1.5.7.2. Enabling Glitch Filtering During Power Analysis
1.5.8. Node and Entity Assignments x
1.5.8.1. Timing Assignments to Clock Nodes
1.7. Scripting Support x
1.7.1. Running the Power Analyzer from the Command–Line
2. Power Optimization x
2.1. Factors Affecting Power Consumption 2.2. Power Dissipation 2.3. Design Space Explorer II for Power-Driven Optimization 2.4. Power-Driven Compilation 2.5. Design Guidelines 2.6. Power Optimization Advisor 2.7. Power Optimization Revision History
2.1. Factors Affecting Power Consumption x
2.1.1. Design Activity and Power Analysis 2.1.2. Device Selection 2.1.3. Environmental Conditions 2.1.4. Device Resource Usage 2.1.5. Signal Activity
2.1.4. Device Resource Usage x
2.1.4.1. Number, Type, and Loading of I/O Pins 2.1.4.2. Number and Type of Hard Logic Blocks 2.1.4.3. Number and Type of Global Signals
2.1.5. Signal Activity x
2.1.5.1. Toggle Rate 2.1.5.2. Static Probability
2.4. Power-Driven Compilation x
2.4.1. Power-Driven Synthesis 2.4.2. Power-Driven Fitter 2.4.3. Area-Driven Synthesis 2.4.4. Gate-Level Register Retiming 2.4.5. Intel® Quartus® Prime Compiler Settings 2.4.6. Assignment Editor Options
2.4.1. Power-Driven Synthesis x
2.4.1.1. Memory Block Optimization 2.4.1.2. Power-Aware Logic Mapping 2.4.1.3. Power-Aware Memory Balancing
2.5. Design Guidelines x
2.5.1. Clock Power Management 2.5.2. Pipelining and Retiming 2.5.3. Architectural Optimization 2.5.4. I/O Power Guidelines Nonterminated I/O Standards Resistively Terminated I/O Standards 2.5.5. Memory Optimization (M20K/MLAB) 2.5.6. DDR Memory Controller Settings 2.5.7. DSP Implementation 2.5.8. Reducing High-Speed Tile (HST) Usage 2.5.9. Unused Transceiver Channels 2.5.10. Periphery Power reduction XCVR Settings
2.5.1. Clock Power Management x
2.5.1.1. Clock Enable in Memory Blocks 2.5.1.2. LAB Clock Power 2.5.1.3. Clock Enables 2.5.1.4. Global Signals 2.5.1.5. Merge Clocks
2.5.1.1. Clock Enable in Memory Blocks x
2.5.1.1.1. Memory Power Reduction Example
2.5.1.2. LAB Clock Power x
2.5.1.2.1. LAB-Wide Clock Enable Example
2.5.1.4. Global Signals x
2.5.1.4.1. Viewing Clock Details in the Chip Planner
2.5.5. Memory Optimization (M20K/MLAB) x
2.5.5.1. Implementation 2.5.5.2. Rd/Wr Enables
2.5.10. Periphery Power reduction XCVR Settings x
2.5.10.1. Transceiver Settings 2.5.10.2. I/O Current Strength
2.6. Power Optimization Advisor x
2.6.1. Set Realistic Timing Constraints 2.6.2. Appropriate Device Family 2.6.3. Dynamic Power 2.6.4. Static Power 2.6.5. Appropriate I/O Standards 2.6.6. Use RAM Blocks 2.6.7. Shut Down RAM Blocks 2.6.8. Clock Enables on Logic 2.6.9. Pipeline Logic to Reduce Glitching
2.6.1. Set Realistic Timing Constraints x
2.6.1.1. Find Timing Information
1. Power Analysis
2. Power Optimization
A. Intel® Quartus® Prime Standard Edition User Guides

2.5.4. I/O Power Guidelines

The Power Analyzer calculates I/O power using the default capacitive load set for the I/O standard in the Capacitive Loading page of the Device and Pin Options dialog box. Any other components defined in the board trace model are not taken into account for the power measurement. For Cyclone®  IV GX, Stratix®  IV, and Stratix® V devices, Advanced I/O Timing considers the full board trace model.

Nonterminated I/O Standards

Nonterminated I/O standards such as LVTTL and LVCMOS have a rail-to-rail output swing. The voltage difference between logic-high and logic-low signals at the output pin is equal to the VCCIO supply voltage. If the capacitive loading at the output pin is known, the following expression determines the dynamic power consumed in the I/O buffer:

where:
  • F is the output transition frequency
  • C is the total load capacitance being switched
  • V is equal to VCCIO supply voltage
Because of the quadratic dependence on VCCIO, lower voltage standards consume significantly less dynamic power.

Transistor-to-transistor logic (TTL) I/O buffers consume very little static power. As a result, the total power that a LVTTL or LVCMOS output consumes is highly dependent on load and switching frequency.

Resistively Terminated I/O Standards

In resistively terminated I/O standards like SSTL and HSTL, the output load voltage swings by a small amount around a bias point. The dynamic power equation above is valid as well, but V is the actual load voltage swing. This voltage is much smaller than VCCIO, resulting in lower dynamic power when comparing to nonterminated I/O under similar conditions.

Resistively terminated I/O standards dissipate significant static (frequency-independent) power, because the I/O buffer is constantly driving current into the resistive termination network. However, the lower dynamic power of these I/O standards means they often have lower total power than LVCMOS or LVTTL for high-frequency applications. As a best practice, when using resistively terminated standards choose the lowest drive strength I/O setting that meets the speed and waveform requirements to minimize I/O power.

You can save a small amount of static power by connecting unused I/O banks to the lowest possible VCCIO voltage.

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