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

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ID 683174
Date 12/04/2023
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Document Table of Contents
Document Table of Contents x
1. Answers to Top FAQs 2. Power Analysis 3. Power Optimization 4. Power Analysis and Optimization Document Archive A. Intel® Quartus® Prime Pro Edition User Guides
2. Power Analysis x
2.1. Power Analysis Tools 2.2. Running the Power Analyzer 2.3. Specifying Power Analyzer Input 2.4. Viewing Power Analysis Reports 2.5. Power Analysis in Modular Design Flows 2.6. Scripting Support 2.7. Power Analysis Revision History
2.3. Specifying Power Analyzer Input x
2.3.1. Settings for Power Analysis 2.3.2. Specifying Signal Activity Data 2.3.3. Specifying the Default Toggle Rate 2.3.4. Specifying Toggle Rates for Specific Nodes 2.3.5. Avoiding Simulation Node Name Match
2.3.2. Specifying Signal Activity Data x
2.3.2.1. Using Simulation Signal Activity Data in Power Analysis 2.3.2.2. Signal Activities from RTL (Functional) Simulation, Supplemented by Vectorless Estimation 2.3.2.3. Signal Activities from Vectorless Estimation and User-Supplied Input Pin Activities 2.3.2.4. Signal Activities from User Defaults Only
2.3.2.1. Using Simulation Signal Activity Data in Power Analysis x
2.3.2.1.1. Generating Signal Activity Data for Power Analysis 2.3.2.1.2. Generating Standard Delay Output for Power Analysis 2.3.2.1.3. Simulation Glitch Filtering
2.3.2.2. Signal Activities from RTL (Functional) Simulation, Supplemented by Vectorless Estimation x
2.3.2.2.1. RTL Simulation Limitation
2.3.4. Specifying Toggle Rates for Specific Nodes x
2.3.4.1. Clock Node Toggle Rates
2.5. Power Analysis in Modular Design Flows x
2.5.1. Complete Design Simulation Power Analysis Flow 2.5.2. Modular Design Simulation Power Analysis Flow 2.5.3. Multiple Simulation Power Analysis Flow 2.5.4. Overlapping Simulation Power Analysis Flow 2.5.5. Partial Design Simulation Power Analysis Flow 2.5.6. Vectorless Estimation Power Analysis Flow
2.5.5. Partial Design Simulation Power Analysis Flow x
2.5.5.1. Specifying Start and End Time for Signal Activity Calculations
2.6. Scripting Support x
2.6.1. Running the Power Analyzer from the Command–Line
3. Power Optimization x
3.1. Factors Affecting Power Consumption 3.2. Design Space Explorer II for Power-Driven Optimization 3.3. Power-Driven Compilation 3.4. Design Guidelines 3.5. Power Optimization Advisor 3.6. Power Optimization Revision History
3.1. Factors Affecting Power Consumption x
3.1.1. Design Activity and Power Analysis 3.1.2. Device Selection 3.1.3. Environmental Conditions 3.1.4. Device Resource Usage 3.1.5. Signal Activity
3.1.4. Device Resource Usage x
3.1.4.1. Number, Type, and Loading of I/O Pins 3.1.4.2. Number and Type of Hard Logic Blocks 3.1.4.3. Number and Type of Global Signals
3.1.5. Signal Activity x
3.1.5.1. Toggle Rate 3.1.5.2. Static Probability
3.3. Power-Driven Compilation x
3.3.1. Power-Driven Synthesis 3.3.2. Power-Driven Fitter 3.3.3. Area-Driven Synthesis 3.3.4. Gate-Level Register Retiming 3.3.5. Intel® Quartus® Prime Compiler Settings 3.3.6. Assignment Editor Options
3.3.1. Power-Driven Synthesis x
3.3.1.1. Memory Block Optimization 3.3.1.2. Power-Aware Logic Mapping 3.3.1.3. Power-Aware Memory Balancing
3.4. Design Guidelines x
3.4.1. Clock Power Management 3.4.2. Pipelining and Retiming 3.4.3. Architectural Optimization 3.4.4. I/O Power Guidelines 3.4.5. Dynamically Controlled On-Chip Terminations (OCT) 3.4.6. Memory Optimization (M20K/MLAB) 3.4.7. DDR Memory Controller Settings 3.4.8. DSP Implementation 3.4.9. Reducing High-Speed Tile (HST) Usage 3.4.10. Unused Transceiver Channels 3.4.11. Periphery Power reduction XCVR Settings
3.4.1. Clock Power Management x
3.4.1.1. Clock Gating 3.4.1.2. Clock Enable in Memory Blocks 3.4.1.3. LAB Clock Power 3.4.1.4. Clock Enables 3.4.1.5. Global Signals 3.4.1.6. Merge Clocks
3.4.1.1. Clock Gating x
3.4.1.1.1. Root Clock Gate 3.4.1.1.2. Sector Clock Gate 3.4.1.1.3. I/O PLL Clock Gate
3.4.1.3. LAB Clock Power x
3.4.1.3.1. LAB-Wide Clock Enable Example
3.4.1.5. Global Signals x
3.4.1.5.1. Viewing Clock Details in the Chip Planner
3.4.6. Memory Optimization (M20K/MLAB) x
3.4.6.1. Implementation 3.4.6.2. Rd/Wr Enables
3.4.11. Periphery Power reduction XCVR Settings x
3.4.11.1. Transceiver Settings 3.4.11.2. I/O Current Strength
3.5. Power Optimization Advisor x
3.5.1. Set Realistic Timing Constraints 3.5.2. Appropriate Device Family 3.5.3. Dynamic Power 3.5.4. Static Power 3.5.5. Appropriate I/O Standards 3.5.6. Use RAM Blocks 3.5.7. Shut Down RAM Blocks 3.5.8. Clock Enables on Logic 3.5.9. Pipeline Logic to Reduce Glitching
3.5.1. Set Realistic Timing Constraints x
3.5.1.1. Find Timing Information
1. Answers to Top FAQs
2. Power Analysis
3. Power Optimization
4. Power Analysis and Optimization Document Archive
A. Intel® Quartus® Prime Pro Edition User Guides

2.3.2.1.3. Simulation Glitch Filtering

The Power Analyzer defines a glitch as two signal transitions so closely spaced in time that the pulse, or glitch, occurs faster than the logic and routing circuitry can respond. The output of a transport delay model simulator contains glitches for some signals. The logic and routing structures of the device form a low-pass filter that filters out glitches that are tens to hundreds of picoseconds long, depending on the device family.

Some third-party simulators use different models than the transport delay model as the default model. Different models cause differences in signal activity and power estimation. The inertial delay model, which is the ModelSim default model, filters out more glitches than the transport delay model and usually yields a lower power estimate.

Note: Intel FPGA recommends that you use the transport simulation model when using the Intel® Quartus® Prime software glitch filtering support with third-party simulators. Simulation glitch filtering has little effect if you use the inertial simulation model.

Glitch filtering in a simulator can also filter a glitch on one logic element (LE) (or other circuit element) output from propagating to downstream circuit elements to ensure that the glitch does not affect simulated results. Glitch filtering prevents a glitch on one signal from producing non-physical glitches on all downstream logic, which can result in a signal toggle rate and a power estimate that are too high. Circuit elements in which every input transition produces an output transition, including multipliers and logic cells configured to implement XOR functions, are especially prone to glitches. Therefore, circuits with such functions can have power estimates that are too high when glitch filtering is not used.

Note: Intel FPGA recommends that you use the glitch filtering feature to obtain the most accurate power estimates. For .vcd files, the Power Analyzer flows support two levels of glitch filtering.

Enable glitch filtering in the .vcd that you generate for use in power analysis by turning on Perform glitch filtering on VCD files.

Figure 11. Enabling Glitch Filtering for VCD

The .vcd file reader performs glitch filtering that is complementary to simulation glitch filtering, but is often less precise. While the .vcd file reader has the ability to remove glitches on logic blocks, the file reader cannot determine how a given glitch potentially affects downstream logic and routing. Filtering the glitches during simulation avoids switching downstream routing and logic automatically.

Note: When running simulation for design verification (rather than to produce input to the Power Analyzer), Intel recommends that you turn off the glitch filtering option to produce the most rigorous and conservative simulation from a functionality viewpoint. When performing simulation to produce input for the Power Analyzer, Intel FPGA recommends that you turn on the glitch filtering to produce the most accurate power estimates.
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