USB 2.0 Controller Higher Current Charging via Reserved Descriptor Bits
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Solution Overview
Problem
USB 2.0 portable devices connected to USB 3.x hosts via a USB 2.0 cable are limited to a maximum charging current of 500 mA, despite the USB 2.0 cable's capability to carry more current, due to USB 2.0 specifications, which restricts faster charging while maintaining compatibility and interoperability.
Innovation Solution
A modified USB 2.0 controller and USB 3.x controller use reserved elements in existing USB 2.0 data structures to request and provide higher charging currents without altering data structure formats, allowing USB 2.0 portable devices to draw up to 900 mA from USB 3.x hosts while remaining compliant with USB 2.0 standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If USB 2.0 specifications are strictly followed to maintain compatibility and interoperability, then USB 2.0 portable devices can remain compliant with USB 2.0 standards, but charging current is limited to maximum 500 mA even when USB 2.0 cables are capable of carrying more current
Solution Approach 1:
The patent changes the parameter interpretation by using reserved bits in existing USB 2.0 data structures to encode higher current capability information. The USB 2.0 controller and USB 3.x controller interpret these reserved bits to negotiate higher charging currents (up to 900 mA) while maintaining the original USB 2.0 data structure formats, thus resolving the contradiction between compliance and power delivery.
2Productivity
If USB 2.0 data structure formats are altered to enable higher charging current requests, then faster charging can be achieved, but USB 2.0 portable devices become incompatible with USB 2.0 standards and fail compliance tests
Solution Approach 1:
The patent makes the existing USB 2.0 data structures multi-functional by utilizing reserved bits that were previously unused. These reserved elements serve dual purposes: maintaining original USB 2.0 compatibility while simultaneously enabling higher current negotiation when both endpoints support it. This allows a single data structure to serve both compliance and enhanced functionality needs.
Data Source
AI summary
Apparatuses, methods, and systems for enabling higher current charging of Universal Serial Bus (USB) Specification Revision 2.0 (USB 2.0) portable electronic devices from USB 3.x hosts are disclosed. In one aspect, a USB 2.0 controller is provided in a USB 2.0 portable device. A USB 3.x controller is provided in a USB 3.x host. The USB 2.0 controller is configured to draw a higher charging current than specified in USB 2.0 for the USB 2.0 portable device over a USB 2.0 cable. In order to draw the higher charging current without violating USB 2.0, the USB 2.0 controller is configured to use one or more reserved elements in an existing USB 2.0 descriptor(s) or bitmap(s) to indicate a higher charging current request from the USB 2.0 controller.