Transition Bins for IC Functional Coverage Verification
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Solution Overview
Problem
Conventional techniques for functional coverage in integrated circuits are computationally inefficient and require excessive memory, making them slow and resource-intensive for simulating and verifying designs.
Innovation Solution
The implementation of transition bins and coverpoints using a Deterministic Finite Automata (DFA) technique and recursive methods to track state transitions and coverpoints, respectively, allows for more efficient simulation by reducing computational time and memory usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional techniques are used for functional coverage, then verification can be performed, but computational time and memory usage become excessive
Solution Approach 1:
The patent segments the functional coverage verification into discrete transition bins, each representing a specific state transition pattern. This segmentation allows the simulator to process coverage tracking in smaller, manageable units rather than handling the entire verification space at once, significantly reducing computational time and memory requirements while maintaining comprehensive verification capability.
Solution Approach 2:
The patent implements dynamic tracking of state transitions using coverpoints that adapt to the actual behavior of the design under test. The system dynamically updates coverage data based on observed transitions, allowing the verification process to focus computational resources on relevant paths rather than exhaustively checking all possible states, thereby reducing overall computational time.
2Reliability
If conventional techniques are used for functional coverage, then verification can be performed, but memory requirements become excessive
Solution Approach 1:
By dividing the verification space into discrete transition bins, the patent reduces the amount of memory required to track coverage. Instead of maintaining comprehensive state information for all possible transitions, the system only needs to store data for the segmented transition patterns defined by the coverpoints, significantly reducing memory usage while preserving verification reliability.
Solution Approach 2:
The patent extracts only the essential information needed for coverage tracking from the full simulation data. By focusing on state transitions rather than complete state space enumeration, the system extracts and stores only the necessary coverage metrics, reducing memory requirements while maintaining verification capability.
3Reliability
If conventional techniques are used for functional coverage, then verification can be performed, but the simulation becomes slow
Solution Approach 1:
The patent performs preliminary definition of coverpoints and transition bins before simulation runs. By pre-configuring the verification framework with expected state transitions, the simulator can efficiently track coverage during execution without performing complex analysis in real-time, thereby maintaining high simulation speed while ensuring comprehensive verification.
Solution Approach 2:
The coverage tracking system serves itself by automatically updating coverage data based on observed transitions without requiring external intervention or complex processing. The system leverages the natural flow of simulation execution to update coverage metrics, eliminating additional computational overhead and maintaining fast simulation speeds while ensuring thorough verification.
Data Source
AI summary
Verification for a design can include, for a covergroup corresponding to a variable of the design, generating a state coverage data structure specifying a plurality of transition bins. Each transition bin can include a sequence. Each sequence can specify states of the variable to be traversed in order during simulation of the design. Verification can include generating a state sequence table configured to use state values as keys and one or more of the sequences as data for the respective keys, and during simulation of the design, maintaining a sequence list specifying each sequence that is running based on sample values of the variable. Hit counts for the transition bins can be updated during the simulation.