eUSB2 Repeater Idle Detection Without CDR or PLL
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Solution Overview
Problem
The implementation of Embedded USB (eUSB2) repeaters faces challenges in communicating with legacy USB systems due to voltage level differences, leading to noise issues from idle signals and the need for large clock data recovery (CDR) or phase locked loop (PLL) components that increase cost and power consumption.
Innovation Solution
A circuit that interfaces between eUSB2 and USB systems, using comparators and logic components to detect idle signals and maintain the last bit of the End of Packet (EOP) indicator for up to four additional bits, preventing noise transmission without requiring CDR or PLL circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CDR or PLL circuits are used to handle voltage level differences and detect idle signals, then communication reliability between eUSB2 and legacy USB systems is improved, but device size and power consumption increase
Solution Approach 1:
The patent extracts the essential function of idle signal detection from complex CDR/PLL circuits by using a simple comparator that monitors the differential voltage between signal lines. This extraction allows the system to achieve reliable idle detection without incorporating the full complexity of CDR or PLL circuits, thereby reducing device size while maintaining communication reliability.
Solution Approach 2:
The patent replaces expensive, complex CDR/PLL circuits with a simple, low-cost comparator circuit. The comparator is a basic electronic component that provides the necessary idle detection functionality without the overhead of complex clock recovery mechanisms, effectively using a simpler, cheaper component to achieve the required function.
2Reliability
If CDR or PLL circuits are used to handle voltage level differences and detect idle signals, then communication reliability between eUSB2 and legacy USB systems is improved, but power consumption increases
Solution Approach 1:
The patent extracts the essential function of idle signal detection from power-intensive CDR/PLL circuits by using a simple comparator that monitors the differential voltage between signal lines. This extraction allows the system to achieve reliable idle detection without incorporating the full complexity of CDR or PLL circuits, thereby reducing power consumption while maintaining communication reliability.
Solution Approach 2:
The patent replaces expensive, power-consuming CDR/PLL circuits with a simple, low-power comparator circuit. The comparator is a basic electronic component that provides the necessary idle detection functionality without the overhead of complex clock recovery mechanisms, effectively using a simpler, lower-power component to achieve the required function.
3Use of energy by moving object
If the transmitter is turned off immediately after EOP indicator transmission, then power consumption is reduced, but noise from idle signals is transmitted to legacy USB systems
Solution Approach 1:
The patent applies preliminary action by detecting the idle signal condition before the transmitter is turned off. The comparator continuously monitors the differential voltage and detects when the signal lines transition to an idle state. This early detection allows the system to maintain the transmitter in an off state for a brief period after EOP transmission without generating noise, as the idle condition is already detected and accounted for.
Solution Approach 2:
The patent uses feedback by continuously monitoring the differential voltage between signal lines with a comparator and using this information to control the transmitter state. The comparator provides real-time feedback about the signal condition, allowing the system to adjust transmitter operation to prevent noise transmission while minimizing power consumption. The feedback mechanism ensures that the transmitter remains off during idle periods when noise generation would be problematic.
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 solution effectively prevents noise transmission while complying with USB specifications, reducing size and power consumption, and enabling efficient communication between eUSB2 and legacy USB systems.
Implementation Method 1
a comparator configured to detect when the differential input signal lines go idle
Implementation Method 2
logic components configured to extend the EOP indicator for up to four additional bits following the detected idle transition
Data Source
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Figure 2
Figure 3
AI summary
Aspects of the disclosure provide for a method (500). In some examples, the method includes receiving, at a circuit, data via a differential input signal (505). The method further includes detecting a falling edge in the data received via the differential input signal (515). The method further includes holding an output of the circuit at a final logical value of the data (520). The method further includes disabling a transmitter of the circuit while holding the output of the circuit at the final logical value of the data (525). The method further includes releasing the output of the circuit from the final logical value of the data (525).