SAS Controller Delayed PHY Activation via Smart Cable Memory
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Solution Overview
Problem
In Serial Attached SCSI (SAS) systems, premature physical link (PHY) activation can lead to repeated discovery processes and link resets, causing inefficiencies in configuration and communication setup.
Innovation Solution
The implementation of a method to disable PHYs at startup, detect and configure smart cables by acquiring parameters from their memory, and enable them only after proper configuration, preventing premature discovery and link resets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If PHYs are activated at startup, then discovery process can begin immediately, but link resets occur repeatedly causing configuration inefficiency
Solution Approach 1:
The patent applies preliminary action by detecting and configuring smart cables with integrated memory before activating the PHYs. The controller reads cable parameters (length, link rate, physical features) from the cable's integrated memory during initialization, configures the PHYs accordingly, and only then enables discovery. This preliminary configuration prevents link resets during discovery, resolving the contradiction between fast discovery and configuration efficiency.
2Loss of time
If PHYs are activated early, then system startup is faster, but improper configuration causes link resets and repeated discovery
Solution Approach 1:
The patent performs preliminary configuration of PHYs based on cable parameters stored in the smart cable's integrated memory before PHY activation. The controller detects the cable type (passive/active, optical/copper), reads the integrated memory for configuration parameters, and configures the PHYs appropriately before enabling them for discovery. This ensures link stability from the start while minimizing startup time loss.
3Productivity
If smart cabling is used to speed up PHY configuration, then cable parameters are available, but premature PHY activation still causes discovery repetition
Solution Approach 1:
The patent leverages the smart cable's integrated memory to perform preliminary PHY configuration before activation. The controller reads cable parameters (length, link rate, physical features) from the integrated memory during system initialization, configures the PHYs with appropriate settings, and only then enables discovery. This preliminary action充分利用 the smart cabling capabilities to prevent discovery repetition, maintaining high productivity while simplifying the overall discovery process.
Data Source
AI summary
Methods and structure for delayed physical link activation in systems that utilize smart cabling are provided. The system includes a Serial Attached Small Computer System Interface (SAS) device comprising a physical link and a controller. The controller is able to disable the physical link to prevent discovery from occurring along the physical link, to detect a cable attached to a physical link, to acquire cable parameters from a memory of the cable, and to configure the physical link based on the acquired cable parameters to enable communications along the cable. The controller is also able to enable the configured physical link to trigger discovery for the physical link.