Adaptive Voltage Scaling for IC Critical Path Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for analyzing the influence of process variation on integrated circuit (IC) signal transmission delay are limited by the need for constant voltage settings, making it difficult to use adaptive voltage scaling techniques and requiring extensive characterization of all components on critical paths, which is time-consuming and results in inaccuracies between simulation and actual IC performance.
Innovation Solution
The method involves executing static timing analysis to identify critical paths, generating a netlist, performing circuit parameter simulations and Monte Carlo simulations at regular voltages to obtain reference values and variances, and conducting adaptive voltage scaling analysis to establish a voltage-versus-parameter relation, allowing for the determination of optimal IC voltage based on these relations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If adaptive voltage scaling technique is used to analyze the influence of signal transmission delay related to process variation, then the analysis accuracy is improved, but it is hard/impossible to implement under constant voltage settings
Solution Approach 1:
The patent applies dynamics by transitioning from static constant voltage analysis to dynamic adaptive voltage scaling analysis. The system dynamically adjusts voltage levels during simulation to match actual operating conditions, enabling accurate analysis of signal transmission delay under varying voltage conditions while maintaining implementation feasibility through automated voltage adjustment protocols
Solution Approach 2:
The patent changes the voltage parameter from a fixed constant value to a variable that scales adaptively according to process variation. By implementing voltage as a dynamic parameter rather than a static setting, the system enables accurate correlation between voltage changes and circuit parameter variations, resolving the contradiction between measurement precision and adaptability
2Reliability
If characterization is carried out with all kinds of variances/models for every component on a critical path of an IC, then the analysis completeness is improved, but it costs a lot of time
Solution Approach 1:
The patent extracts only the critical path components from the entire IC design for characterization, rather than analyzing every component. By identifying and isolating the critical path using timing analysis, the system maintains analysis completeness for timing-critical elements while dramatically reducing the time required compared to full-IC characterization
Solution Approach 2:
The patent segments the IC design into critical path and non-critical path portions, applying detailed variance analysis only to the critical path segment. This segmentation allows the system to maintain reliability for timing-critical analysis while reducing overall characterization time by excluding non-critical components from exhaustive modeling
3Ease of operation
If process variances/models are used for analysis under constant voltage setting, then the simulation simplicity is improved, but the analysis scope is confined and cannot handle adaptive voltage scaling
Solution Approach 1:
The patent transforms the simulation from a static constant-voltage process to a dynamic adaptive voltage scaling process. The simulation automatically adjusts voltage levels according to process variation models, maintaining operational simplicity through automated control while expanding voltage range coverage to include all relevant operating conditions
4Productivity
If the analysis using a characterization library model is performed, then the analysis speed is improved, but the result differs from critical path circuit simulation by 0-5 percent
Solution Approach 1:
The patent applies local quality by using detailed process variation models specifically for critical path components rather than generic characterization library models. This localized application of high-precision modeling to timing-critical elements maintains analysis speed while improving accuracy, reducing the discrepancy between simulation and actual circuit behavior
Data Source
AI summary
Disclosed is an IC voltage determining method including: executing a static timing analysis according to a circuit design to obtain data of a critical path and then generating a netlist; executing a circuit parameter simulation and Monte Carlo simulation with the netlist according to a regular voltage and prescribed parameters to obtain a circuit parameter reference value and a variance of circuit parameter values; executing an adaptive voltage scaling analysis according to a voltage range to obtain a voltage-versus-parameter relation indicative of the number of times that each of circuit parameter deviations that are respectively associated with predetermined voltages within the predetermined voltage range is of the variance; and testing an IC according to the regular voltage to obtain a circuit parameter test value and determining the IC voltage according to the voltage-versus-parameter relation and a difference between the circuit parameter test value and the circuit parameter reference value.