Timing Margin Monitor Circuit for Supply Voltage Attack Detection
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Solution Overview
Problem
Existing voltage tampering techniques in integrated circuits compromise security functions by manipulating supply voltages outside normal operating parameters, leading to timing failures and potential data theft.
Innovation Solution
A fully-digital, compact timing margin monitor (TMM) sensor circuit with auto-alignment functionality, using a tunable delay circuit, time-to-digital converter, and control circuit to monitor supply voltage fluctuations and detect voltage attacks, providing real-time digital codes and threshold-based alarm signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage tampering is performed by manipulating supply voltage outside normal operating parameters, then timing requirements are violated causing timing failures, but security functions are compromised allowing content theft
Solution Approach 1:
The patent implements preliminary detection of voltage tampering by continuously monitoring supply voltage before timing failures occur. The detection circuit identifies voltage manipulations early, allowing the system to take preventive actions such as triggering security responses or adjusting operating parameters before timing requirements are violated and security is compromised.
Solution Approach 2:
The patent employs feedback mechanisms where detection circuits continuously monitor supply voltage and provide real-time information to control logic. This feedback loop enables dynamic adjustment of system operation in response to detected voltage tampering, maintaining timing requirement compliance while preventing security compromises by responding to voltage changes as they occur.
2Measurement precision
If extensive calibration requirements and manual alignment are implemented for voltage-delay monitoring, then measurement precision is improved, but device complexity and ease of manufacture deteriorate
Solution Approach 1:
The patent implements self-aligning detection circuits that automatically calibrate themselves without requiring extensive manual intervention. The circuit performs self-calibration by utilizing internal reference signals and automatic adjustment mechanisms, thereby maintaining high measurement precision for voltage-delay monitoring while significantly reducing device complexity and easing manufacturing processes.
Solution Approach 2:
The patent utilizes parameter changes in the detection circuit to enable automatic alignment and calibration. By dynamically adjusting circuit parameters such as delay values and reference voltages based on measured conditions, the system achieves high measurement precision without requiring complex manual calibration procedures, thus reducing device complexity.
3Ease of operation
If a timing margin monitor circuit with auto-alignment functionality is implemented, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple functions including voltage monitoring, delay measurement, auto-alignment, and threshold comparison into a single integrated timing margin monitor circuit. By merging these functions into one unified device, the circuit achieves ease of operation with auto-alignment functionality while minimizing the increase in device complexity compared to implementing separate circuits for each function.
Data Source
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AI summary
A detection circuit includes a tunable delay circuit that generates a delayed signal and that receives a supply voltage. The detection circuit includes a control circuit that adjusts a delay provided by the tunable delay circuit to the delayed signal. The detection circuit includes a time-to-digital converter circuit that converts the delay provided by the tunable delay circuit to the delayed signal to a digital code and adjusts the digital code based on changes in the supply voltage. The control circuit causes the tunable delay circuit to maintain the delay provided to the delayed signal constant in response to the digital code reaching an alignment value. The detection circuit may continuously monitor timing margin of a data signal relative to a clock signal and update the digital code in every clock cycle. The detection circuit may be a security sensor that detects changes in the supply voltage.