Dynamic Voltage Drop Analysis Using Constrained Signal Toggling
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Solution Overview
Problem
Existing dynamic voltage drop (DVD) simulations in electrical circuit design are inefficient due to random signal toggling methods that fail to accurately represent real-world scenarios, leading to pessimistic or optimistic results and increased simulation times, especially when only a portion of the design changes.
Innovation Solution
The identification and constraining of correlated groups of signals or pins within the circuit design to simulate toggling in a more realistic manner, combined with the use of reduced models like microcircuits for localized and efficient dynamic voltage drop analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If purely random selection of signals is used for toggling in dynamic voltage drop analysis, then the simulation is fast and easy to perform, but the results are pessimistic and may include impossible toggle patterns that do not occur in actual circuit operation
Solution Approach 1:
The patent changes the parameters of signal toggling from completely random to constrained random toggling. Correlated groups of signals are identified based on their electrical relationships (series/parallel connections, shared power domains), and toggling constraints are applied to these groups to prevent physically impossible patterns while maintaining randomness within valid patterns. This resolves the contradiction by maintaining simulation speed through automated constraint application while improving accuracy by eliminating impossible toggle scenarios.
Solution Approach 2:
The simulation system automatically identifies correlated signal groups and applies appropriate toggling constraints without requiring manual intervention. The system serves itself by autonomously determining which signals are correlated based on circuit topology analysis and automatically generating constrained random toggle patterns, thus maintaining productivity while improving measurement precision.
2Measurement precision
If timed logical propagation is used to determine downstream signal toggling from randomly selected register toggles, then the simulation provides more realistic toggle patterns, but the computational expense increases significantly
Solution Approach 1:
The patent extracts and applies toggling constraints directly at the signal level based on pre-identified correlated groups, rather than performing full timed logical propagation through the entire circuit. This takes out the computationally expensive propagation step and replaces it with direct constraint application, maintaining realistic toggle patterns while significantly reducing computational complexity.
Solution Approach 2:
The patent performs preliminary identification of correlated signal groups and establishes toggling constraints before the actual dynamic voltage drop simulation. This preliminary action pre-computes the relationships and constraints that would otherwise require expensive timed propagation during the simulation, thus improving accuracy while reducing computational complexity during the actual analysis phase.
3Measurement precision
If existing software simulators perform full dynamic voltage drop simulation across the entire integrated circuit, then complete coverage of all switching conditions is achieved, but the simulation time increases and it becomes impractical when only a portion of the design has changed
Solution Approach 1:
The patent segments the integrated circuit into correlated groups of signals based on their electrical relationships and power domain associations. By applying toggling constraints at the group level rather than simulating every individual signal transition across the entire circuit, the method achieves comprehensive coverage of relevant switching conditions while significantly reducing simulation time. This segmentation allows focused analysis on affected regions when design changes occur.
Solution Approach 2:
The patent applies partial action by focusing the dynamic voltage drop analysis only on correlated signal groups that are actually affected by design changes, rather than performing exhaustive simulation of the entire circuit. This partial analysis achieves sufficient coverage for practical design validation while dramatically reducing simulation time compared to full-circuit simulation.
Data Source
AI summary
Methods, systems and media for simulating or analyzing voltage drops in a power distribution network can use an iterative approach to define a portion of a design around a victim to capture a sufficient collection of aggressors that cause appreciable voltage drop on the victim. This approach can be both computationally efficient and accurate and can limit the size of the data used in simulating dynamic voltage drops in the power distribution network.