Low-Speed Serial Bus Self-Healing via Watchdog Heartbeats

Solution Overview

Problem

The use of software or hardware-based polling to detect stuck SDA signals in the MIPI I3C bus creates overhead and inefficiencies, increasing the probability of bus errors and impacting response times.

Innovation Solution

Implementing a watchdog timer and heart-beat commands in target devices, with periodic heart-beat commands and response checks, allowing for self-reset and reduced software overhead, thereby enhancing bus efficiency and reducing error propagation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If software or hardware-based polling is used to detect stuck SDA signals, then bus error detection capability is maintained, but software overhead increases and transaction response times deteriorate

Engineering Contradiction:

Improvebus error detection capabilityVSAvoidtransaction response times

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The target device autonomously monitors the SDA signal using a dedicated circuit and performs self-reset when a stuck condition is detected, eliminating the need for controller-based polling and enabling independent error recovery without impacting transaction response times

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces software-based polling mechanisms with a dedicated hardware circuit that continuously monitors the SDA signal, substituting mechanical/software operations with an optimized hardware solution that provides continuous monitoring without overhead

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If software or hardware-based polling is used to detect stuck SDA signals, then bus error detection capability is maintained, but software overhead increases

Engineering Contradiction:

Improvebus error detection capabilityVSAvoidsoftware overhead

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The target device autonomously monitors the SDA signal using a dedicated circuit and performs self-reset when a stuck condition is detected, eliminating the need for controller-based polling and enabling independent error recovery without impacting transaction response times

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces software-based polling mechanisms with a dedicated hardware circuit that continuously monitors the SDA signal, substituting mechanical/software operations with an optimized hardware solution that provides continuous monitoring without overhead

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If periodic heart-beat commands are implemented for bus monitoring, then bus efficiency is improved and error propagation is reduced, but additional communication overhead is introduced

Engineering Contradiction:

Improvebus efficiencyVSAvoidcommunication overhead

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The target device autonomously monitors the SDA signal using a dedicated circuit and performs self-reset when a stuck condition is detected, eliminating the need for controller-based polling and enabling independent error recovery without impacting transaction response times

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12481546B2Self-healing low speed serial interface

Publication Date: 2025.11.25 INTEL CORP

AI summary

An apparatus and method to monitor status of a serial data signal on a low speed serial bus is provided. A controller configures a watchdog timer in each target device, sends a heart-beat command to all of the target devices over the low speed serial bus prior to the expiration of the watchdog timer and issues a broadcast read command to any one of the target devices on the low speed serial bus. A response to the broadcast read command confirms that the low speed serial bus is functional. If a response is not received, the low speed serial bus is not functional and the controller initiates a broadcast reset command to initialize all target devices on the low speed serial bus.