USB Endpoint Multiplexing for Multi-Function Devices

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Solution Overview

Problem

USB devices are limited by hardware restrictions in the number of supportable endpoints, making it costly and complex to implement multi-functional devices, as increasing endpoints leads to higher hardware complexity and costs.

Innovation Solution

Implementing USB endpoint multiplexing, where a single USB device supports multiple functional devices by receiving a request for switching through a data endpoint, searching for the corresponding functional device based on a user-selected identifier, and switching to that device, allowing for multiple functions without increasing hardware complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of USB endpoints is increased to support multiple functional devices, then the multi-functionality of the USB device is improved, but the hardware complexity and cost are increased

Engineering Contradiction:
Improvemulti-functionalityVSAvoidhardware complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by enabling a single USB endpoint to serve multiple functional devices through dynamic switching. The control endpoint receives switching requests and reconfigures the data endpoint to communicate with different functional devices sequentially, allowing one physical endpoint to perform multiple functions that would traditionally require separate dedicated endpoints for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If the number of USB endpoints is increased to support multiple functional devices, then the multi-functionality of the USB device is improved, but the hardware cost is increased

Engineering Contradiction:
Improvemulti-functionalityVSAvoidhardware cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent reduces hardware cost by making the data endpoint universal rather than dedicated. Instead of providing separate data endpoints for each functional device, the system uses a single shared data endpoint that is dynamically assigned to different functions through control endpoint management, eliminating the need for additional expensive hardware components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the communication paths for multiple functional devices into a single shared data endpoint. By combining what would traditionally be separate dedicated communication channels into one shared resource managed through switching control, the system reduces the total number of hardware components required while maintaining the ability to support multiple functions.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If multiple sets of USB endpoints are added to support multiple functions, then the function coverage is improved, but the device complexity is increased

Engineering Contradiction:
Improvefunction coverageVSAvoidendpoint quantity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the USB device into two distinct endpoint types: a control endpoint for management and switching operations, and a shared data endpoint for actual data communication. This segmentation allows the control endpoint to orchestrate switching between multiple functional devices while the single data endpoint handles all data traffic, reducing the total endpoint quantity while maintaining comprehensive function coverage.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2211272B1Method and device for implementing USB endpoint multiplexing
Publication Date: 2011.09.28 HUAWEI DEVICE CO LTD
  • EP2211272B1 patent drawingFigure 1~2
  • EP2211272B1 patent drawingFigure 3
  • EP2211272B1 patent drawingFigure 4~5

AI summary

A method and device for implementing USB endpoint multiplexing are disclosed. The USB device of the present disclosure supports at least two USB functional devices, and the number of the USB functional devices that are supported by the USB device is larger than the number of data endpoints of the USB device. The method includes: receiving a request for switching over USB functional devices, where the request carries a function identifier of a USB functional device selected by a user; searching for the USB functional device corresponding to the function identifier according to the function identifier; and switching the USB device to the searched USB functional device. The devices include: a USB device and a host. By multiplexing the USB endpoints, the present disclosure achieves an object of using one USB device as a multi-functional device, and hence saves the cost and enhances the user's experience.