Digital Entropy Source Circuit Using TDC Delay Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current random number generators for electronic systems require analog circuits like oscillators and thermal noise samplers, making it difficult to integrate them into an all-digital design flow, which increases costs and design schedules.
Innovation Solution
An entropy source circuit comprising an input data control circuit, a digital circuit, a determination circuit, and a Time-to-Digital Converter (TDC) that converts the delay of digital circuit operations into a digital signal, eliminating the need for additional analog circuits and enabling integration into an all-digital design flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If analog circuits such as oscillators and thermal noise samplers are used to generate random numbers, then high quality true random numbers can be generated, but it becomes difficult to integrate them into an all-digital design flow and increases manufacturing costs and design schedules
Solution Approach 1:
The patent replaces analog circuits (oscillators, thermal noise samplers) with a digital circuit that uses Time-to-Digital Conversion (TDC) to generate random numbers. The TDC measures the propagation delay of digital signals through logic gates, converting time delays into digital values that exhibit randomness. This substitution eliminates the need for analog components while maintaining random number generation capability, enabling full digital design flow integration.
Solution Approach 2:
The patent changes the fundamental parameter used for random number generation from analog physical phenomena (thermal noise, oscillator jitter) to digital signal propagation delay. By measuring and digitizing the time delays through logic gates using TDC, the system transforms a digital timing parameter into random number output, fundamentally changing the generation mechanism from analog to digital domain.
2Reliability
If analog circuits are used for random number generation, then true random numbers can be generated, but additional analog components increase manufacturing costs and extend design schedules
Solution Approach 1:
The patent substitutes analog random number generation circuits with a fully digital implementation using TDC. The digital circuit measures propagation delays of logic gates and converts these time measurements into random number output. This eliminates analog components entirely, streamlining the manufacturing process and reducing design schedule while maintaining true random number generation capability.
Solution Approach 2:
The patent makes the TDC circuit serve multiple functions: it acts as both a timing measurement device and a random number generator. By measuring propagation delays through logic gates and digitizing these measurements, the TDC simultaneously performs time-to-digital conversion and entropy extraction, eliminating the need for separate analog random number generation hardware.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An entropy source circuit (10, 30, 40) is provided. The entropy source circuit (10, 30, 40) includes an input data control circuit (110), a digital circuit (130), a determination circuit (140) and a time-to-digital converter (150). The input data control circuit (110) is configured to output a start signal, input data, and reference data corresponding to the input data. The digital circuit (130) has an input terminal configured to receive the input data. The determination circuit (140) is configured to receive the reference data, wherein when an output generated on an output terminal of the digital circuit (130) is equal to the reference data, the determination circuit (140) generates a determination signal. The time-to-digital converter (150) is configured to receive the start signal and generate entropy data according to the start signal and the determination signal.