Abstract: A memory subsystem with positional read data latency that includes one or more memory modules, a memory controller and one or more memory busses is provided. The memory controller includes instructions for providing positional read data latency. The memory modules and the memory controller are interconnected via the memory busses.

Abstract: A memory chip comprises an internal voltage regulator that is selectively enabled/disabled to regulate an external voltage used by the memory chip subunit.

Abstract: A method and apparatus for determining correct timing for receiving, in a host in a memory system, of a normal toggle transmitted by an addressed memory chip on a bidirectional data strobe. An offset in the data strobe is established, either by commanding the addressed memory chip, in a training period, to drive the data strobe to a known state, except during transmission of a normal toggle, or by providing a voltage offset between a true and a complement phase in the data strobe, or by providing a circuit bias in a differential receiver on the host the receives the data strobe. A series of read commands are transmitted by the host to the addressed memory chip, which responds by transmitting the normal toggle. Timing of reception of the normal toggle as received by the host chip is adjusted until the normal toggle is correctly received.

Abstract: A hub device, memory system, and method for providing a cascade interconnect memory system with enhanced reliability. The hub device includes an interface to a high-speed bus for communicating with a memory controller. The memory controller and the hub device are included in a cascade interconnect memory system and the high-speed bus includes bit lanes and one or more clock lanes. The hub device also includes a bi-directional fault signal line in communication with the memory controller and readable by a service interface. The hub device also includes a fault isolation register (FIR) for storing information about failures detected at the hub device, the information including severity levels of the detected failures. In addition, the hub device includes error recovery logic for responding to a failure detected at the hub device.

Abstract: A communication interface device, system, method, and design structure for error correcting code (ECC) protected quasi-static bit communication (SBC) on a high-speed bus are provided. The communication interface device includes high-speed sampling logic to capture high-speed data from the high-speed bus using a high-speed sampling clock and SBC sampling logic to capture SBC samples from the high-speed bus using an SBC sampling clock. The SBC sampling clock is slower than the high-speed sampling clock. The communication interface device also includes an SBC finite state machine (FSM) to detect a received SBC command in response to a static pattern persisting for a predetermined number of the SBC samples and command decoding logic to decode the received SBC command.

Abstract: A memory system, having indeterminate read data latency, that includes a memory controller and one or more hub devices. The memory controller is configured for receiving data transfers via an upstream channel and for determining whether all or a subset of the data transfers include a data frame by detecting a frame start indicator. The data frame includes an identification tag that is utilized by the memory controller to associate the data frame with a corresponding read instruction issued by the memory controller. The one or more hub devices are in communication with the memory controller in a cascade interconnect manner via the upstream channel and a downstream channel. Each hub device is configured for receiving the data transfers via the upstream channel or the downstream channel and for determining whether all or a subset of the data transfers include a data frame by detecting the frame start indicator.

Abstract: A method for providing frame start indication that includes receiving a data transfer via a channel in a memory system. The receiving is in response to a request, and at an indeterminate time relative to the request. It is determined whether the data transfer includes a frame start indicator. The data transfer and “n” subsequent data transfers are captured in response to determining that the data transfer includes a frame start indicator. The data transfer and the “n” subsequent data transfers make up a data frame, where “n” is greater than zero.

Abstract: A system and method for providing a cyclical redundancy code (CRC) for use in a high-speed serial link. The system includes a cascade interconnect memory system including a memory controller, a memory hub device and a downstream link. The downstream link is in communication with the memory controller and the memory hub device and includes at least thirteen signal lanes for transmitting a multiple transfer downstream frame from the memory controller to the memory hub device. A portion of the downstream frame includes downstream CRC bits to detect errors in the downstream frame. The downstream CRC bits capable of detecting any one of a lane failure, a transfer failure and up to five bit random errors.

Abstract: A method and system for providing identification tags in a memory system having indeterminate data response times. An exemplary embodiment includes a memory controller in a memory system. The memory controller includes a mechanism for receiving data packets via an upstream channel, the data packets including upstream identification tags. The memory controller also includes a mechanism having instructions for facilitating determining if a received data packet is in response to a request from the memory controller. Input to the determining includes an upstream identification tag included in the received data packet. If the received data packet is determined to be in response to a request from the memory controller, then the received data packet is matched to the request, thereby allowing the memory controller to operate with indeterminate data response times.

Abstract: A method and system for providing frame start indication in a memory system having indeterminate read data latency. The method includes receiving a data transfer and determining if the data transfer includes a frame start indicator. The method also includes capturing the data transfer and “n” subsequent data transfers in response to determining that the data transfer includes a frame start indicator. The data transfer and the “n” subsequent data transfers comprise a data frame.

Abstract: A memory system is provided that performs error correction at a memory device level. The memory system comprises a memory hub device integrated in the memory module and a link interface integrated in the memory hub device that provides a communication pathway between the memory hub device and an external memory controller. The link interface comprises first error correction logic integrated in the link interface that performs error correction operations on first data that is received from the external memory controller via a first memory channel to be transmitted to a set of memory devices. The first error correction logic generates a first error signal to the external memory controller in response to the first error correction logic detecting a first error in the first data. Link interface control logic integrated in the link interface controls the transmission of the first data to the set of memory devices.

Abstract: A memory buffer, memory system and method for power-on initialization and test for a cascade interconnect memory system. The memory buffer includes a bus interface to links in a high-speed channel for communicating with a memory controller via a direct connection or via a cascade interconnection through an other memory buffer. The interface is operable in a SBC mode and a high-speed mode. The memory buffer also includes a field service interface (FSI) slave for receiving FSI signals from a FSI master. In addition, the memory buffer includes logic for executing a power-on and initialization training sequence initiated by the memory controller.

Abstract: A Planar Memory Module (PAMM) device comprising a generally planar card comprising a first side and a second side, the first side having a plurality of couplings and the second side having a plurality of connectors, a plurality of memory devices coupled to the card via a first portion of the plurality of couplings, and at least one hub chip coupled to the card via a second portion of the plurality of couplings. Each of the plurality of couplings is connected to an associated one of the plurality of connectors.

Abstract: A memory subsystem with a memory bus and a memory assembly. The memory bus includes multiple bitlanes. The memory assembly is in communication with the memory bus and includes instructions for receiving an error code correction (ECC) word in multiple packets via the memory bus. The ECC word includes data bits and ECC bits arranged into multiple multi-bit ECC symbols. Each of the ECC symbols is associated with one of the bitlanes on the memory bus. The memory assembly also includes instructions for utilizing one of the ECC symbols to perform error detection and correction for the bits in the ECC word received via the bitlane associated with the ECC symbol.

Abstract: A memory system with delay locked loop (DLL) bypass control including a method for accessing memory that includes receiving a memory read command at a memory device. The memory device is configured to operate in a DLL off-mode to bypass a DLL clock as input to generating a read clock. A DLL power-on command is received at the memory device and in response to receiving the DLL power-on command a DLL initialization process is performed at the memory device. The memory read command is serviced at the memory device operating in the DLL off-mode, the servicing overlapping in time with performing the DLL initialization process. The memory device is configured to operate in a DLL on-mode to utilize the DLL clock as input to generating the read clock in response to a specified period of time elapsing. The specified period of time is relative to receiving the DLL power-on command.

Abstract: Providing homogeneous recovery in a redundant memory system that includes a memory controller, a plurality of memory channels in communication with the memory controller, an error detection code mechanism configured for detecting a failing memory channel, and an error recovery mechanism. The error recovery mechanism is configured for receiving notification of the failing memory channel, for blocking off new operations from starting on the memory channels, for completing any pending operations on the memory channels, for performing a recovery operation on the memory channels and for starting the new operations on at least a first subset of the memory channels. The memory system is capable of operating with the first subset of the memory channels.

Abstract: Failing bus lane detection using syndrome analysis, including a method for receiving a plurality of syndromes of an error detection code, the error detection code associated with a plurality of frames that have been transmitted on a bus that includes a plurality of lanes and is protected by the error detection code. The method includes performing for each of the lanes in each of the syndromes: decoding the syndrome under an assumption that the lane is a failing lane, the decoding outputting a decode result; determining if the decode result is a valid decode; and voting for the lane in response to determining that the decode result is a valid decode. A failing lane is then identified in response to the voting, with the failing lane being characterized by having more votes than at least one other lane on the bus.

Abstract: Error correction and detection in a redundant memory system that includes a memory controller; a plurality of memory channels in communication with the memory controller, the memory channels including a plurality of memory devices; a cyclical redundancy code (CRC) mechanism for detecting that one of the memory channels has failed, and for marking the memory channel as a failing memory channel; and an error correction code (ECC) mechanism. The ECC is configured for ignoring the marked memory channel and for detecting and correcting additional memory device failures on memory devices located on one or more of the other memory channels, thereby allowing the memory system to continue to run unimpaired in the presence of the memory channel failure.

Abstract: Isolation of faulty links in a transmission medium including a method that includes receiving an atomic data unit via a multi-link transmission medium that has a plurality of transmission links An error condition is detected and it is determined that the error condition is isolated to a single transmission link. It is determined if the single transmission link has been isolated previously as a failing transmission link a specified number of times within an interval specified by a timer. If the single transmission link has been isolated previously as a failing transmission link a specified number of times within an interval specified by a timer then: identifying the single transmission link as a faulty transmission link; resetting the timer; and outputting an identifier of the single transmission link.

Abstract: Providing heterogeneous recovery in a redundant memory system that includes a memory controller, a plurality of memory channels in communication with the memory controller, an error detection code mechanism configured for detecting a failing memory channel, and an error recovery mechanism. The error recovery mechanism is configured for receiving notification of the failing memory channel, for performing a recovery operation on the failing memory channel while other memory channels are performing normal system operations, for bringing the recovered channel back into operational mode with the other memory channels for store operations, for continuing to mark the recovered channel to guard against stale data, for removing any stale data after the recovery operation is complete, and for removing the mark on the recovered channel to allow the normal system operations with all of the memory channels, the removing in response to the removing any stale data being complete.