Detecting High Impedance Nets via Programmable Resistors
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Solution Overview
Problem
Hazardous high impedance nets in electronic circuits can cause unpredictable switching behavior, making them difficult to detect using existing methods, which are often unreliable and time-consuming, especially in low-power designs.
Innovation Solution
A simulation method that connects programmable resistors between transistor terminals to identify voltage fluctuations, followed by the application of current sources to detect potentially hazardous high impedance nets, reducing computational complexity and avoiding false positives by modeling leakage and simulating the circuit's behavior over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing detection methods (analog simulator, manual inspection, CCK, dynamic check) are used to detect hazardous high impedance nets, then detection coverage is achieved, but detection reliability is poor and false warnings are generated
Solution Approach 1:
The patent introduces an intermediary detection mechanism by connecting programmable resistors between transistor terminals before applying test signals. This intermediary component allows the system to indirectly detect high impedance nets by measuring voltage fluctuations caused by leakage currents, avoiding the false warnings generated by direct connection methods while maintaining detection accuracy.
Solution Approach 2:
The patent applies preliminary action by first connecting programmable resistors to model leakage currents before injecting test signals. This preliminary setup creates a more realistic detection scenario that accounts for actual circuit behavior, improving both detection accuracy and reliability by preventing false positives from misleading test conditions.
2Reliability
If current sources are directly connected to all transistor terminals for detection, then comprehensive testing is achieved, but computational complexity increases significantly
Solution Approach 1:
The patent segments the detection process into two stages: first identifying transistors with voltage fluctuations using programmable resistors, then applying current sources only to those specific transistors. This segmentation reduces the number of transistors requiring full testing, thereby lowering computational complexity while maintaining comprehensive detection coverage for hazardous high impedance nets.
Solution Approach 2:
The patent applies partial action by using programmable resistors to perform preliminary screening of all transistors, then applying the more resource-intensive current source testing only to a subset of transistors showing voltage fluctuations. This approach achieves sufficient detection coverage without the excessive computational complexity of testing all transistors with current sources.
3Measurement precision
If energy is injected into the electronic circuit using current sources or voltage sources for detection, then hazardous high impedance nets can be identified, but false positives are generated in unsupplied circuit parts
Solution Approach 1:
The patent uses programmable resistors as intermediary components that model realistic leakage currents between transistor terminals. This intermediary approach allows detection without directly injecting energy into unsupplied circuit parts, thereby maintaining detection capability while avoiding false positives that would otherwise be generated in powered-off regions of the circuit.
Solution Approach 2:
The patent changes the detection parameter from direct energy injection to measuring voltage fluctuations caused by programmable resistors modeling leakage currents. This parameter change enables detection in supplied circuit regions while avoiding false positives in unsupplied regions, as the programmable resistors only create realistic leakage scenarios where power is actually present.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively identifies and reduces the number of transistors to be tested, improving detection efficiency and accuracy, ensuring the reliability of electronic circuit designs by pinpointing hazardous high impedance nets and preventing energy mismanagement.
Implementation Method 1
connecting programmable resistors between two terminals of each transistor... wherein said electrical connection is characterized by a relatively high electrical impedance
Implementation Method 2
By connecting current sources with the first terminals of the first group of transistors, a potentially hazardous high impedance net may be detected
Data Source
AI summary
A simulation method and a corresponding medium storing processor-executable code for detecting a high impedance net within an electronic circuit comprising a plurality of transistors is presented. The simulation method includes the step of connecting programmable resistors between two terminals of each transistor. Subsequently, voltage fluctuations are determined at the first terminals of a first group of transistors, where the voltage fluctuations are caused by connecting the programmable resistors. By connecting current sources with the first terminals of the first group of transistors, a potentially hazardous high impedance net may be detected within the electronic circuit.