ML Delay Estimation for Emulation Timing Graph Routing

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Solution Overview

Problem

Conventional delay estimation methods for combinatorial paths in DUTs result in inaccurate placement and routing, leading to inefficient use of processing resources and emulation slowdowns due to incorrect delay calculations.

Innovation Solution

A machine learning-based delay estimation system that predicts combinatorial path delays using a feature vector and a trained delay model, providing accurate timing guidance during compilation phases to improve partitioning and routing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single delay estimate is used for all combinatorial paths, then the estimation process is simple and fast, but the accuracy of delay determination deteriorates, causing compilers to overlook true critical delays

Engineering Contradiction:
Improvedelay determination accuracyVSAvoiddelay estimation process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the delay estimation process by dividing combinatorial paths into different categories based on their characteristics (e.g., path length, logic depth, routing complexity). Different delay estimation models are applied to different segments of paths, allowing accurate delay determination for each path type while avoiding the need for a completely new estimation system. This segmentation enables the system to achieve high measurement precision without overwhelming complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameters used in delay estimation by introducing multiple delay models that account for different path characteristics. Instead of using a single fixed estimation method, the system adjusts estimation parameters based on path type, logic depth, and routing complexity. This parameter adaptation allows accurate delay determination across diverse combinatorial paths while maintaining manageable process complexity through systematic parameter selection.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If inaccurate delay estimates are used, then the compilation process is faster and simpler, but emulation speed deteriorates and processing resources are wasted

Engineering Contradiction:
Improveemulation speedVSAvoidtime wasted on incorrect delay calculations
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by performing delay estimation during the compilation process itself, rather than after. The system estimates delays for combinatorial paths as part of the compilation workflow, providing accurate timing information that guides placement and routing decisions. This preliminary delay determination enables faster emulation by avoiding iterative corrections and resource waste from incorrect delay calculations, while the estimation process is integrated into existing compilation steps to minimize additional time consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where delay estimation results are used to guide compilation decisions, and compilation results are fed back to refine delay estimates. The system uses initial delay estimates to perform placement and routing, then measures actual delays and uses this feedback to improve subsequent estimation accuracy. This feedback loop ensures that emulation runs at optimal speeds while minimizing time wasted on incorrect calculations by continuously refining delay determination based on actual performance data.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If more detailed delay estimation is performed for each combinatorial path, then delay accuracy improves, but processing resource consumption increases

Engineering Contradiction:
Improvecombinatorial path delay accuracyVSAvoidprocessing resource consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by tailoring delay estimation methods to specific path characteristics rather than applying a uniform detailed estimation to all paths. The system analyzes path properties such as length, logic depth, and routing complexity to determine the appropriate estimation level for each path. This localized approach ensures high measurement precision for critical paths while using minimal processing resources for less critical paths, optimizing the balance between accuracy and resource consumption.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by performing detailed delay estimation only for a subset of combinatorial paths that are most likely to be critical, rather than exhaustively analyzing all paths. The system identifies candidate critical paths based on heuristics and path characteristics, then applies detailed estimation only to these selected paths. This partial estimation approach achieves sufficient delay accuracy for optimization while significantly reducing processing resource consumption compared to complete path analysis.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4217904B1Machine learning delay estimation for emulation systems
Publication Date: 2025.12.03 SYNOPSYS INC
  • EP4217904B1 patent drawingFigure 1
  • EP4217904B1 patent drawingFigure 2
  • EP4217904B1 patent drawingFigure 3

AI summary

A delay estimation system estimates a delay of a DUT tor an emulation system. The delay estimation system receives logic blocks of the DUT and a combinatorial path connecting one or more of the logic blocks. The system applies a delay model to a feature vector representing the combinatorial path, where the delay model can determine a delay of the combinatorial path. The delay model may be a machine learning model. The system generates a timing graph using the determined delay and provides the timing graph to a compiler to perform placement and routing of the DUT.