Pmc-sierra, Inc.

Pmc-sierra Us, Inc.

Microsemi Storage Solutions (u.s.), Inc.

Microsemi Solutions (us), Inc.

Microchip Technology Inc.

Larrie Simon Carr

Heng Liao

Winston K Mok

Winston Ki-Cheong Mok

Kuan Hua Tan

Richard David Sodke

Keith Graham Shaw

Guillaume Fortin

Gregory Arthur Tabor

Robert Kristian Watson

Patrick Neil Bailey

Sanjay Goyal

Yuiry Greshishchev

Alex Cochran

Junqi (Paul) Hua

Graeme Barclay Boyd

John Matthew Adams

Yuriy Greshishchev

Kris Iniewski

Steven F Lang

David Joseph Clinton

Kenneth Evert Sailor

Curtis Brian Lapadat

Richard Arthur John Steedman

Atit Patel

Travis James Karr

Martin Chalifoux

Glenn Kenneth Bindley

Alan Nakamoto

Salman Ghufran

Kaihong Wang

Monika Swic

Patrick Bailey

Nicholas Kuefler

Nicolas Kuefler

Alexander John Cochran

Gordon Robert Oliver

Manthiramoorthy Ponmanikandan

Richard A J Steadman

Steven Forbes Lang

Richard Arthur Steedman

System and method for analyzing CXL flits at read bypass detection logic to identify bypass memory read requests and transmitting the identified bypass memory read requests over a read request bypass path directly to a transaction/application layer of the CXL memory controller, wherein the read request bypass path does not include an arbitration/multiplexing layer and a link layer of the CXL memory controller, thereby reducing the latency inherent in a CXL memory controller.

System and method for bypass memory read request detection

Methods, devices, and systems relating to Serial Attached SCSI (SAS) storage interconnect technology are provided. An SAS serial connection is established between an SAS initiator and an SAS expander over a physical link for communications between the SAS initiator and a plurality of target devices. The plurality of target devices is in communication with the SAS expander. SAS packets associated with each of the plurality of target devices are dynamically multiplexed and transmitted over the single SAS serial connection. Each SAS packet comprises one or more information bits indicating the target device with which the SAS packet is associated. The dynamically multiplexed SAS packets transmitted over the SAS connection may comprise SAS packets associated with at least two target devices having different maximum physical link rates. A result may be improved bandwidth utilization of the physical link when legacy SAS target devices with slower physical link rates are utilized.

Fractional multiplexing of serial attached small computer system interface links

The disclosure generally relates to a PCIe switch that includes a selectively transparent bridge that selectively allows transactions to traverse between multiple PCIe domains without the encumbrance of each root complex entity requiring knowledge of the selectively transparent bridge. The bridge that enables the transactions is invisible to the root complex entity in a host and drive switch domain of the PCIe switch. No address translation of the transactions is required because the drive switch domain address map is a subset of the host switch domain address map. The bridge allows for extremely low latency transactions between host systems and storage drives because the bridge allows the storage drive to read the Direct Memory Access (DMA) Scatter-Gather List (SGL) directly from host memory. The bridge also allows I/O data reads and writes from the storage drive directly to the host memory without store and forward within a RAID controller's memory.

Method and switch for transferring transactions between switch domains

A data integrity (DI) protection circuit and method provide overlapping DI protection without increasing memory requirements. Write data parity is checked after write data error correcting code (ECC) check bits are generated, which is stored with the write data in memory without storing the write data parity. A corrupt location cache stores the write address and a write response error is generated when a write data parity error or write address parity error is detected. Read data and read data ECC check bits retrieved from the memory are checked and single bit errors are corrected, while double-bit errors result in a read error response. Read data parity is generated, and the corrected read data and corrected read data ECC check bits are then checked for bit errors. The corrupt location cache is searched for the read address, and a cache hit results in a read error response.

Overlapping data integrity for semiconductor devices

Provided is an apparatus and method for enabling interoperability between a serial attached small computer system interface (SAS) protocol with a peripheral component interconnect express (PCIe) protocol. A SAS-PCIe bridge includes a SAS component configured to communicate with a SAS device in a SAS domain and a PCIe component configured to communicate with a PCIe switch in a PCIe domain. The SAS component and the PCIe component are configured to convert data between the SAS protocol and the PCIe protocol.

Apparatus and method for interoperability between SAS and PCI express

SAS/SATA Store-Forward (SSSF) buffering enables SAS/SATA block storage devices capable of slower physical link rates to transfer data at a SAS topology data rate. 6 Gbps SAS and SATA disk drives can exchange data at 12 Gbps with 12 Gbps hosts through 12 Gbps SAS expanders employing an SSSF device. The SSSF device improves data transfer performance in the storage area network by optimizing host-side link utilization. The device includes a host-side interface communicating with the host at a host-side rate, a drive-side interface communicating with the target at a drive-side rate equal to or less than the host-side rate, a buffer receiving SAS frames or SATA FIS's, and control logic to control communication between the host-side interface and buffer at the host-side rate and between the drive-side interface and the buffer at the drive-side rate.

SAS/SATA store-and-forward buffering for serial-attached-SCSI (SAS) storage network

Techniques and apparatus for a clock and data recovery circuit to lock to data having frequency offsets relative to a local clock reference are disclosed. One embodiment includes a multi-step frequency tracking system in which each step is used to track a sub-range of frequency deviation from local clock reference. The frequency tracking sub-range of each step is selected so that the clock and data recovery system is relatively assured of achieving lock when the frequency of the incoming data lies within or is relatively near the frequency tracking sub-range of the selected step. Embodiments may use control signals to select the sub-ranges, and hence guide the frequency tracking portion of the clock and data recovery circuit to operate in a frequency tracking range that is optimized for achieving and maintaining lock.

Clock and data recovery locking technique for large frequency offsets

A system and method for providing redundant access paths to a storage device make use of a processor to analyze instructions received from hosts to allow for command queuing, host switching, and command replacement where necessary. The system allows for either Serially Attached SCSI or Serial ATA hard drives to be connected to the same topology and to require no host intervention on the coordination of drive access in a multi-host environment. A single ported SATA device can then appear multi-ported and can support a redundant architecture within a SAS topology.

Apparatus for interconnecting hosts with storage devices

Broadcast primitive filtering in a SAS expander using virtual domains. The virtual domains can be non-overlapping or overlapping logical subsets of the physical topology, or a logical construct based on the membership of a device within a group. Broadcast event propagation is handled in accordance with predetermined policies associated with the virtual domains. These policies can, for example, include limiting the broadcast traffic within the boundaries of the logical zones defined by the subsets, or routing the broadcast events in accordance with access policies, or privileges, associated with the group.

Method and apparatus for broadcast primitive filtering in SAS

A method and system are provided for broadcast message filtering in SAS expanders. Common SAS topology defined by ANSI T10 specification only supports spanning tree topology (without loops) interconnection among multiple end devices and expander devices. Broadcast message filtering provides a mechanism to selectively discard broadcast messages, or primitives, in the SAS expanders to break the infinite loop path that broadcast primitives can traverse. This enables new SAS physical topologies with loops that are otherwise difficult or impossible to realize using SAS expanders that handle primitive broadcasts according to the definition of the SAS standard. By allowing redundant paths in a SAS topology, the problem of infinite broadcast flooding in SAS topology is reduced. Selectively forwarding broadcast messages can be based on whether the broadcast was originated at the source phy, or received by the source phy, or based on whether the source phy is a filtered phy.

Serial attached SCSI broadcast primitive processor filtering for loop architectures

A method and apparatus for determining a set of common link rates for communication between two storage network elements in a storage network system. During the speed negotiation process, a controlling storage network element receives supported link rate information from a connected storage network element without providing any information in return. By not providing such information, although the speed negotiation process may not be completed, the controlling storage network element is still able to determine the supported link rates of the connected storage network element.

Method of rate snooping in a SAS/SATA environment

A multi-port switch and a method of command switching using such a switch. Multiple virtual targets provide multiple hosts with access to the physical target device attached to the target interface of the switch. The switch intelligently dispatches operations received by the virtual targets to the physical storage target device to provide shared access. In doing so, the communication between the switch and the physical target can fully comply with the SATA protocol without the physical target being aware that the operations have originated from multiple physical hosts, and without the multiple physical hosts being aware of the shared nature of the physical SATA target device.

Command switching for multiple initiator access to a SATA drive

A method and apparatus are provided for routing in an SAS expander for logical zoning. Common SAS topology defined by the ANSI T10 specification only relates to physical topology with multiple end devices, as well as to expander devices and the broadcast handling mechanisms in such physical topologies. The present invention introduces the concept of virtual topologies that can be non-overlapping or overlapping subsets of the physical topology and the routing mechanism that handles the routing issues with the virtual topologies.

Method and apparatus for routing in SAS using logical zones

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Kelowna, Canada

Larrie Simon Carr