USB Sideband I2C Tunneling via SATL Address Translation

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Solution Overview

Problem

Existing USB communication protocols face inefficiencies in tunneling low-speed I2C signals, leading to higher power consumption and the need for additional pins and conductors, especially when using USB 4.0 sideband channels for low-speed communication.

Innovation Solution

Implementing a slave address table lookup (SATL) circuit to translate I2C signals through a USB 4.0 sideband channel, allowing low-speed I2C signals to be routed independently of high-speed channels, reducing power consumption and eliminating the need for additional pins and conductors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If USB high-speed interface is used for low-speed I2C communication, then communication capability is provided, but power consumption increases and additional pins/conductors are required

Engineering Contradiction:
Improvecommunication capabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The USB interface is segmented into high-speed and low-speed channels. The patent separates I2C tunneling traffic from high-speed USB traffic by using the low-speed sideband channel specifically for I2C communication, allowing each channel to operate independently at its optimal speed and power consumption level.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different communication protocols to different channels based on their characteristics. The low-speed sideband channel is specifically optimized for I2C protocol tunneling, while the high-speed channel handles USB data traffic, ensuring each channel operates with appropriate quality for its intended purpose.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If USB high-speed interface is used for low-speed I2C communication, then communication capability is provided, but additional pins and conductors are needed

Engineering Contradiction:
Improvecommunication capabilityVSAvoidpins and conductors
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The USB sideband channel, originally designed for configuration and control functions, is made multi-functional by enabling it to tunnel I2C communication in addition to its original purposes. This eliminates the need for separate dedicated pins and conductors for I2C communication.

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

Solution Approach 2:

The USB sideband channel acts as an intermediary that enables I2C communication between devices connected via USB. Instead of requiring direct I2C pins, the sideband channel mediates the communication by tunneling I2C packets through the USB interface.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If I2C signals are routed through USB high-speed channel, then communication is enabled, but resource usage efficiency decreases

Engineering Contradiction:
Improvecommunication routingVSAvoidresource usage efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments communication traffic into appropriate channels based on speed requirements. Low-speed I2C traffic is routed through the low-speed sideband channel while high-speed USB traffic uses the high-speed channel, optimizing resource utilization and preventing bandwidth waste.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4237955B1Tunneling over universal serial bus (USB) sideband channel
Publication Date: 2025.07.09 QUALCOMM INC
  • EP4237955B1 patent drawingFigure 1A~2
  • EP4237955B1 patent drawingFigure 3
  • EP4237955B1 patent drawingFigure 4~5

AI summary

Tunneling over Universal Serial Bus (USB) sideband channel systems and methods provide a way to tunnel I2C transactions between a master and slaves over USB 4.0 sideband channels. More particularly, a slave address table lookup (SATL) circuit is added to a host circuit. Signals from an I2C bus are received at the host, and any address associated with a destination is translated by the SATL. The translated address is passed to a low-speed interface associated with a sideband channel in the host circuit. Signals received at the low-speed interface are likewise reverse translated in the SATL and then sent out through the I2C bus. In this fashion, low-speed I2C signals may be routed over the sideband channel through the low-speed sideband interface portion of the USB interface.