Abstract: A SAS expander adaptively configures a Serial-Attached-SCSI (SAS) PHY to accommodate varying lengths of a cable coupling the PHY to a remote PHY. The expander (a) configures the SAS PHY with settings of an entry of a table of PHY configuration settings, each entry in the table having different PHY configuration setting values; (b) clears a counter; (c) operates the PHY to communicate with the remote PHY for a monitoring period, after configuring the PHY and clearing the counter; (d) increments the counter when the PHY detects a PHY event during the monitoring period, and otherwise decrements the counter; (e) repeats steps (c) and (d) unless the counter rises above a threshold; and (f) when the counter rises above the threshold, repeats steps (a) through (e), wherein step (a) is performed with the settings of a different entry of the table.

Abstract: A SAS expander includes SAS PHYs for transceiving signals with SAS devices on corresponding SAS links coupled to the SAS PHYs. The SAS expander includes status registers that provide fault detection parameters concerning communications on the SAS links. A microprocessor of the SAS expander identifies faulty communications on one of the SAS links, based on the fault detection parameters, and disables a corresponding one of the SAS PHYs coupled to the SAS link on which the microprocessor identified the faulty communications. The microprocessor may also report the PHY disabling to a SAS initiator. The microprocessor may also re-enable the PHY after corrective action is taken, such as in response to user input, an indication from a SAS device, or automatically detecting the corrective action. The expander may also automatically take the corrective action. The fault detection parameters may include error counters and corresponding thresholds, interrupt indicators, and state values.

Abstract: A SAS expander includes SAS PHYs for transceiving signals with SAS devices on corresponding SAS links coupled to the SAS PHYs. The SAS expander includes status registers that provide fault detection parameters concerning communications on the SAS links. A microprocessor of the SAS expander identifies faulty communications on one of the SAS links, based on the fault detection parameters, and disables a corresponding one of the SAS PHYs coupled to the SAS link on which the microprocessor identified the faulty communications. The microprocessor may also report the PHY disabling to a SAS initiator. The microprocessor may also re-enable the PHY after corrective action is taken, such as in response to user input, an indication from a SAS device, or automatically detecting the corrective action. The expander may also automatically take the corrective action. The fault detection parameters may include error counters and corresponding thresholds, interrupt indicators, and state values.