Abstract: A system and method for improving message passing between a computer and peripheral devices is disclosed. The system and method for improving message passing between a computer and peripheral devices incorporate data checking on the command/message data and each scatter gather list element. The method in accordance with the present disclosure enables a peripheral device to check the integrity of the message and ownership of the scatter gather list element before the data is processed.

Abstract: A system and method for improving message passing between a computer and peripheral devices is disclosed. The system and method for improving message passing between a computer and peripheral devices incorporate data checking on the command/message data and each scatter gather list element. The method in accordance with the present disclosure enables a peripheral device to check the integrity of the message and ownership of the scatter gather list element before the data is processed.

Abstract: Apparatus and methods for improved high-speed communication by exchanging low-speed information regarding the high-speed exchanges over the same communication medium. In one exemplary embodiment, a communication device includes a high-speed transceiver adapted to exchange high-speed data with another device via a communication medium using high-frequency signals. The device also includes a low-speed component adapted to exchange low-speed information over the same communication medium as low-frequency signals. The low-frequency signals may be applied as common mode signals to a differential communication path so as to not interfere with the high-speed data exchanges. In another embodiment, a high-pass filter may be included in the device to remove the low-frequency signals before the high-speed data is applied to the high-speed transceiver. Responsive to receipt of the low-speed information, a device may adjust parameters of the transceiver to improve the high-speed data exchanges.

Abstract: Apparatus and methods for improved high-speed communication by exchanging low-speed information regarding the high-speed exchanges over the same communication medium. In one exemplary embodiment, a communication device includes a high-speed transceiver adapted to exchange high-speed data with another device via a communication medium using high-frequency signals. The device also includes a low-speed component adapted to exchange low-speed information over the same communication medium as low-frequency signals. The low-frequency signals may be applied as common mode signals to a differential communication path so as to not interfere with the high-speed data exchanges. In another embodiment, a high-pass filter may be included in the device to remove the low-frequency signals before the high-speed data is applied to the high-speed transceiver. Responsive to receipt of the low-speed information, a device may adjust parameters of the transceiver to improve the high-speed data exchanges.

Abstract: Methods and systems for automatically, dynamically reconfiguring multiplexing functions of a PHY of a SAS device in response to monitored performance of the PHY and/or in response to changes in configuration of devices in the SAS domain. A SAS device such as a SAS initiator or a SAS expander in a SAS domain may monitor performance of PHYs of the device to detect bandwidth utilization and may reconfigure multiplexing functions of a PHY to improve bandwidth utilization of the PHYs of the device. The device may also detect changes in the topology of the SAS domain such as addition of new devices or removal of device and adjust multiplexing functions of its PHYs accordingly to improve performance of communications in the SAS domain.

Abstract: Methods and structures within a SAS expander for detecting link level errors in PHYs of a SAS expander to reduce overhead bandwidth utilization of SAS links between SAS initiators and SAS expanders. In one aspect hereof, a SAS expander self monitors the error status registers of its own PHYs over an internal path that does not use bandwidth of the attached SAS links. When a link level error is so detected the SAS expander may initiate actions and/or report the error to a SAS initiator to thereby reduce the potential for lost data integrity. Where multiple SAS expanders are configured in a SAS domain fabric, each expander may monitor its PHYs or one expander may be designated a master and monitor PHYs of all expanders in the fabric.

Abstract: Methods and structures within a SAS expander for testing SAS devices and other SAS expanders in the SAS domain. Testing devices and expanders in the domain by operations performed within a SAS expander in the domain relieves the burden of such processing in attached host systems and adds flexibility for scheduling processing for test operation of devices and expanders in the domain. In one aspect hereof, the testing may be performed by a master SAS expander configured in the domain. The SAS expander may initiate testing of devices following completion of the SAS discovery process. Testing may also be initiated in response to events in the SAS domain not typically detected by attached host systems.

Abstract: Methods and structures within a SAS expander for initiating communication with one or more SAS initiators in a SAS domain to inform the initiators of sensed changes in the domain without the need for a full SAS Discovery process. In one aspect hereof, the expander may transmit a vendor unique BROADCAST primitive to inform SAS initiators that they should initiate a vendor unique SMP or SSP exchange with the expander to determine changes to the SAS domain. In another aspect hereof, the SAS initiator may respond as an SMP or SSP target device in response to initiation of vendor unique SMP or SSP exchanges by the expander. The expander may report to initiators regarding sensed changes in the domain and/or statistics regarding operation of the expander or other elements of the domain.