Integrated Circuit Self-Test Signal Inversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional built-in self-test circuits in integrated circuits cannot perform their intended functions concurrently with self-testing, limiting the ability to continuously monitor the circuit's functionality.
Innovation Solution
An integrated circuit with a sensor and diagnostic circuit that generates a self-diagnostic signal by alternating between the sensor output signal and its inverted form, allowing for continuous monitoring of the circuit's status without disrupting its operational mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional built-in self-test circuits are activated to test the integrated circuit, then the functionality of the circuit can be verified, but the circuit cannot perform its intended function concurrently with the self-test
Solution Approach 1:
The patent divides the circuit into separate functional blocks: a sensor portion for detecting physical quantities and a switch portion for signal routing. This segmentation allows the self-test circuit to operate independently from the main circuit functionality, enabling concurrent operations. The sensor portion can be tested without disrupting the switch portion's normal operation.
Solution Approach 2:
The patent implements periodic self-test activation where the self-test circuit is activated at specific intervals rather than continuously. This allows the main circuit to perform its intended functions during most operation time, while the self-test is conducted periodically to verify functionality. The self-test is activated in response to specific events or time periods without interfering with normal operation.
2Reliability
If the built-in self-test circuit exercises all circuits in particular ways, then comprehensive testing is achieved, but the circuit cannot maintain normal operational mode during testing
Solution Approach 1:
The patent introduces a switch portion as an intermediary component that can route signals to different destinations. During self-test operations, the switch portion directs test signals to specific circuit elements for verification. During normal operation, the switch portion routes signals for the intended function. This intermediary allows the same circuit infrastructure to serve both testing and operational purposes without interference.
Solution Approach 2:
The patent applies local quality by testing specific portions of the circuit independently. The sensor portion can be tested separately from the switch portion, and each component can be verified in its specific operational context. This allows comprehensive testing of individual elements without requiring the entire circuit to be in a specific operational state, maintaining normal operation while achieving complete testing coverage.
3Reliability
If the self-diagnostic signal inverts the sensor output signal, then fault detection capability is improved, but signal processing complexity increases
Solution Approach 1:
The patent employs signal inversion as a simple yet effective fault detection mechanism. The self-diagnostic signal inverts the sensor output signal, so that a logical high becomes low and vice versa. This inversion allows the circuit to distinguish between normal operation and fault conditions by comparing the inverted signal against expected values. The inversion operation is computationally simple and does not significantly increase processing complexity while substantially improving fault detection capability.
Data Source
AI summary
An integrated circuit includes a sensor for providing a sensor output signal and a diagnostic circuit coupled to the sensor for providing a self-diagnostic signal. The self-diagnostic signal comprises the sensor output signal during a first time duration and an inverted sensor output signal during a second different time duration.