eUSB2 Device Disconnect Detection via Digital Ping
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Solution Overview
Problem
The standard USB2 protocol faces challenges with high power consumption and integration issues due to 3.3 Volt signaling, making it unsuitable for devices with stringent power consumption requirements, such as mobile platforms, and advanced semiconductor processes that cannot tolerate higher voltages.
Innovation Solution
The eUSB2 protocol employs lower signal voltage and reduced power consumption through simplified physical layer architecture, using 1 Volt CMOS circuitry for digital communication, eliminating analog components, and implementing a device ping for idle mode detection to reduce power consumption, while supporting Low-Speed, Full-Speed, and High-Speed operations with low-swing differential signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard USB2 protocol uses 3.3 Volt signaling for communication, then communication reliability is improved, but power consumption increases and integration becomes difficult in advanced semiconductor processes
Solution Approach 1:
The patent changes the voltage parameter from 3.3V to 1.0V signaling level, enabling operation in advanced semiconductor processes (22nm and below) while reducing power consumption by approximately 75%. This parameter change allows the system to maintain communication functionality while adapting to lower voltage constraints of modern CMOS processes.
Solution Approach 2:
The patent replaces the analog signaling mechanism with a fully digital communication scheme. By eliminating analog components such as current sources and operational amplifiers, the system achieves lower power consumption and better integration in digital CMOS processes, while maintaining USB 2.0 protocol compatibility.
2Strength
If standard USB2 protocol uses 3.3 Volt signaling, then signal strength is improved, but integration challenges arise in very low geometry semiconductor processes
Solution Approach 1:
The patent changes the voltage parameter from 3.3V to 1.0V signaling level, enabling operation in advanced semiconductor processes (22nm and below) while reducing power consumption by approximately 75%. This parameter change allows the system to maintain communication functionality while adapting to lower voltage constraints of modern CMOS processes.
3Ease of operation
If standard USB2 protocol maintains constant DC path with pull-up and pull-down resistors for device detection, then device presence detection is simplified, but power consumption increases during idle state
Solution Approach 1:
The patent implements periodic device ping signals during idle modes (L0 and L1) to detect device presence. Instead of maintaining a constant DC path with pull-up and pull-down resistors, the system uses periodic digital ping signals, enabling the downstream port to detect device disconnect events while consuming minimal power during idle states.
Solution Approach 2:
The patent removes the constant DC path formed by pull-up and pull-down resistors during idle states. By extracting this always-on power consumption element and replacing it with periodic digital ping detection, the system eliminates unnecessary power draw while maintaining device presence detection capability.
Data Source
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AI summary
Systems and methods for operating a universal serial bus are described herein. The method includes sending packet data from a USB2 device to a USB2 host on a pair of signal lines, and after sending the packet data, sending an End-Of-Packet (EOP) signal from the USB2 device to the USB2 host. The method also includes, entering the USB2 device into idle state after sending the EOP signal. The method also includes sending a digital ping from the USB2 device to the USB2 host to indicate device presence during idle state.