Transaction Intervention Module for Interconnect Deadlock Recovery

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Solution Overview

Problem

Integrated processor systems face system-level deadlocks due to unresponsive master devices, which necessitate full system restarts, conflicting with the trend towards fault-tolerant systems that require higher functional availability during faults.

Innovation Solution

A transaction intervention module is introduced between the interconnect component and master devices to finalize outstanding transactions by monitoring the functional state of master devices and initiating transaction intervention, including timer management and data buffering to prevent system-level deadlocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a full system restart is performed to recover from system-level deadlock, then the system can be recovered from the deadlock state, but the system response time increases significantly and functional availability decreases

Engineering Contradiction:
Improvesystem recovery capabilityVSAvoidsystem response time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the interconnect transactions into two categories: new transactions and outstanding transactions. The transaction intervention module selectively applies different handling strategies to each segment, allowing outstanding transactions to be finalized while new transactions are blocked, thereby resolving deadlock without requiring a full system restart and minimizing response time loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The transaction intervention module acts as an intermediary component between the master device and the interconnect component. It monitors the functional state of master devices and intervenes in transaction processing when a deadlock is detected, finalizing outstanding transactions through this intermediate layer without affecting the entire system, thus maintaining functional availability during recovery.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a full system restart is performed to recover from system-level deadlock, then the system can be recovered from the deadlock state, but the functional availability during fault conditions decreases

Engineering Contradiction:
Improvesystem recovery capabilityVSAvoidfunctional availability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments transaction handling into distinct paths for new and outstanding transactions. When a master device enters a failure state, the transaction intervention module allows outstanding transactions to be finalized while blocking new transactions from the affected master device. This segmentation enables the system to maintain partial functionality and higher availability during fault conditions without requiring a complete system restart.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The transaction intervention module enables the interconnect component to self-manage deadlock recovery by automatically detecting the functional state of master devices and selectively finalizing outstanding transactions. This self-service mechanism allows the system to recover from deadlocks autonomously without external intervention or full system restart, thereby maintaining higher functional availability during fault conditions.

Inventive Principle:
Principle #25Self-service

3Productivity

If the interconnect component serves outstanding transactions to an unresponsive master device, then the interconnect component can maintain transaction processing, but a system-level deadlock occurs

Engineering Contradiction:
Improvetransaction processing capabilityVSAvoidsystem stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The transaction intervention module implements a feedback mechanism by continuously monitoring the functional state of master devices. When a master device becomes unresponsive (indicating a failure state), the monitoring function detects this condition and triggers the intervention logic to finalize outstanding transactions and block new transactions from that master device, preventing system-level deadlock while maintaining overall system stability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces dynamic transaction handling where the interconnect component's behavior changes based on the functional state of master devices. The transaction intervention module dynamically adjusts transaction processing by finalizing outstanding transactions for unresponsive masters while blocking new transactions, creating a adaptive system that maintains stability without sacrificing transaction processing capability for responsive devices.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3321814B1Method and apparatus for handling outstanding interconnect transactions
Publication Date: 2020.09.23 NXP USA INC
  • EP3321814B1 patent drawingFigure 1~2
  • EP3321814B1 patent drawingFigure 3~7
  • EP3321814B1 patent drawingFigure 4~5

AI summary

A method and apparatus for handling outstanding interconnect transactions between a master device and an interconnect component. For example, a transaction intervention module (140) coupled to an interconnect component (110) and a master device (120) of the interconnect component (110). The transaction intervention module (140) is arranged to receive an indication (125) of a functional state of the master device (120). If the master device (120) is indicated as being in a faulty functional state the transaction intervention module (140) is further arranged to determine whether any interconnect transactions initiated by the master device (120) with the interconnect component (110) are outstanding. If it is determined that at least one interconnect transaction initiated by the master device (120) is outstanding, the transaction intervention module (140) is arranged to finalise the at least one outstanding interconnect transaction with the interconnect component (110).