Time-to-Digital Circuit Timing for Asynchronous Key Communication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Asynchronous clock signals between electronic devices and host devices in communication systems, such as vehicle electronic key systems, lead to measurement errors and inaccuracies in determining relay attacks, affecting the reliability of authentication and distance measurement.
Innovation Solution
A circuit device with a time-to-digital conversion circuit that measures the time difference between transition timings of start and stop signals based on reception and transmission data or clock signals, providing accurate processing time and synchronization error information to the control circuit, even when clock signals are asynchronous.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate clock signals are used for electronic device and host device, then each device can operate independently, but measurement accuracy of processing time deteriorates due to asynchronous clock signals
Solution Approach 1:
A time-to-digital conversion circuit is introduced as an intermediary component that measures the time difference between transition timings of start and stop signals. This circuit converts time measurements into digital values that can be processed by the control circuit, serving as a mediator between the asynchronous clock signals and the processing time measurement requirement.
Solution Approach 2:
The patent replaces the traditional mechanical counting method (counting clock cycles) with a time-to-digital conversion mechanism. Instead of relying on clock signal cycles to measure time, the system uses transition timing detection and digital conversion, which is more accurate and not affected by clock signal asynchronism.
2Ease of manufacture
If clock signal counting is used for processing time measurement, then simple implementation is achieved, but measurement accuracy deteriorates due to clock signal asynchronism
Solution Approach 1:
The time-to-digital conversion circuit acts as an intermediary that bridges the gap between simple implementation and accurate measurement. It provides a straightforward digital output that can be easily processed while achieving high measurement accuracy through transition timing detection.
Solution Approach 2:
The time-to-digital conversion circuit automatically performs the time measurement and conversion without requiring complex external synchronization mechanisms. The circuit self-manages the measurement process by detecting transition timings and generating digital values, simplifying the overall system implementation.
Data Source
AI summary
A circuit device is used in an electronic device including a receiver, a control circuit that performs processing on reception data received by the receiver using a clock signal, a transmitter that transmits transmission data generated by performing processing based on the reception data by the control circuit. The circuit device includes a time-to-digital conversion circuit that measures a time difference between a transition timing of a start signal based on the reception data and a transition timing of a stop signal based on the transmission data or the clock signal, and an output interface that outputs, to the control circuit, a measurement result of the time difference of the time-to-digital conversion circuit.