Abstract: Various embodiments of the present invention provide systems and methods for format efficient data storage. As an example, a data storage device is described that includes: a storage medium, a read/write head assembly, and a read channel circuit. The read/write head assembly is disposed in relation to the storage medium and operable to sense information corresponding to an encoded codeword. The read channel circuit is operable to receive the encoded codeword. The read channel circuit includes a missing symbols insertion circuit, a codeword de-scramble circuit, an address insertion circuit, and a data decoder circuit. The missing symbols insertion circuit, the codeword de-scramble circuit, and the address insertion circuit together are operable to pad a derivative of the encoded codeword with a plurality of symbols, to de-scramble the derivative of the encoded codeword, and to insert address information corresponding to the derivative of the encoded codeword to yield a modified encoded codeword.

Abstract: Methods and structure are disclosed for normalizing storage performance across a plurality of logical volumes. One embodiment is a storage controller. The storage controller is adapted to couple with a plurality of host systems and a storage device. The storage controller is adapted to receive one or more requests to create logical volumes for the plurality of hose systems, and adapted to identify a plurality of performance zones for storage areas of the storage device. The performance zones exhibit different performance criteria for one or more of: reading data from the storage device and writing data to the storage device. The storage controller is further adapted to allocate storage from each of the plurality of performance zones for each of the plurality of logical volumes such that the performance criteria for accessing the storage device is distributed substantially uniformly across the plurality of logical volumes.

Abstract: A test pattern is encoded using a run length limited line encoding to produce an encoded block of data. The encoded block of data is sent via a channel. A plurality of bits in the received block of data that are subsequent to a maximum length run in the sent data is compared to an expected plurality of bits. A type of bit error is classified based on a mismatch between the expected plurality of bits and the plurality of bits in the received block of data.

Abstract: A method for detecting an information pattern includes obtaining a first sample stream and a second sample stream. The first sample stream and the second sample stream are obtained by sensing recorded information at a target location of a storage medium using a first sensor and a second sensor, respectively. A first metric is computed by comparing the first sample stream to a reference pattern representative of a target information pattern to be detected. A second metric is computed by comparing the second sample stream to the reference pattern. A combined metric is computed by combining the first metric and second metric using a weighting function. The target information pattern is detected using the combined metric.

Abstract: A data storage controller exposes information stored in a locally managed volatile memory store to a host system. The locally managed volatile memory store is mapped to a corresponding portion of a peripheral component interconnect express (PCIe) compliant memory space managed by the host system. Backup logic in the data storage controller responds to a power event detected at the interface between the data storage controller and the host system by copying the contents of the volatile memory store to a non-volatile memory store on the data storage controller. Restore logic restores a data storage controller state by copying the contents of the non-volatile memory store to the locally managed volatile memory store upon the application of power such that the data in the volatile memory store is persistent even in the event of a loss of power to the host system and or the data storage controller.

Abstract: In one embodiment, an integrated circuit (IC) device includes a first logic block having performance characteristics, a first critical path monitor (CPM) configured to monitor the performance characteristics of the first logic block, and a first CPM envelope circuit enveloping the first CPM. The first logic block is configured to operate in at least one of a first functional mode and a first scan mode. The first CPM is adapted to operate in at least one of a second functional mode and a second scan mode. The first and second functional modes use higher clock frequencies, respectively, than the first and second scan modes. The first CPM envelope circuit comprises a clock-gate circuit adapted to allow the IC device to operate in a mixed mode, wherein the first CPM operates in the second functional mode while the first logic block operates in the first scan mode.

Abstract: A flash memory controller having soft-decoding error correcting code (ECC) logic generates log likelihood ratio or similar ECC decoder soft input information from decision patterns obtained from reading data from the same portion of flash memory two or more times. Each decision pattern corresponds to a voltage region bordering one of the reference voltages. Each decision pattern represents a combination of flash memory bit value decisions for a cell voltage within the voltage region corresponding to the decision pattern when a corresponding combination of the reference voltages are used to read the cell. Numerical values are then computed in response to combinations of the flash memory bit value decisions represented by the decision patterns. The numerical values are provided to the soft-decoding ECC logic to serve as soft input information.

Abstract: Systems and methods relating generally to solid state memory, and more particularly to systems and methods for recovering data from a solid state memory.

Abstract: A method of adjusting a post-cursor tap weight in a transmitter FIR filter in a high-speed digital data transmission system. A receiver, over a forward channel, receives a signal from the transmitter and equalizes the received signal using an adaptive analog equalizer coupled to the forward channel and a decision feedback equalizer (DFE) coupled to the analog equalizer. A gain coefficient used to adjust the peaking by the analog equalizer is adapted using an error signal generated by the DFE. The post-cursor tap weight of the transmitter filter is adjusted up or down based on a comparison of the gain coefficient to a set. of limits. The post-cursor tap weight is transmitted to the transmitter over a reverse channel and then equalizers in the receiver readapt. Alternatively, eye opening data and a DFE tap coefficient are used to determine whether the post-cursor tap weight is adjusted up or down.

Abstract: A system, method, and computer program product are provided for a host device to request and obtain failure information from a solid state drive (SSD). In operation, an error is detected during an operation associated with a solid state drive. Additionally, a command to return failure information is provided to the solid state drive by a host device. Further, the failure information is sent from the solid state drive to the host device, the failure information including failure information associated with the solid state drive.

Abstract: Aspects of the disclosure pertain to a system and method for detecting server removal from a cluster to enable fast failover of storage (e.g., logical volumes). A method of operation of a storage controller of a cluster is disclosed. The method includes receiving a signal. The method further includes, based upon the received signal, determining that communicative connection between a second storage controller of the cluster and the first storage controller of cluster is unable to be established. The method further includes determining whether communicative connection between the first storage controller and expanders of first and second enclosure services manager modules of the cluster is able to be established. The method further includes, when it is determined that communicative connection between the first storage controller and the expanders of the first and second enclosure services manager modules of the cluster is able to be established, performing a failover process.

Abstract: Systems and method relating generally to solid state memory, and more particularly to systems and methods for recycling data in a solid state memory.

Abstract: A method and system for self-sizing dynamic cache for virtualized environments is disclosed. The preferred embodiment self sizes unequal portions of the total amount of cache and allocates to a plurality of active virtualized machines (VM) according to VM requirements and administrative standards. As a new VM may emerge and request an amount of cache, the cache controller reclaims currently used cache from the active VM and reallocates the unequal portions of cache required by each VM. To ensure cache availability, a quick reclamation amount of cache is immediately available to each new VM as it makes the request begins operation. After reallocation, the newly created VM may rely on a guaranteed minimum quota of cache to ensure performance.

Abstract: An apparatus for low density parity check decoding includes a variable node processor operable to generate variable node to check node messages and to calculate perceived values based on check node to variable node messages, a check node processor operable to generate the check node to variable node messages and to calculate checksums based on the variable node to check node messages, and a scheduler operable to determine a layer processing order for the variable node processor and the check node processor based at least in part on the number of unsatisfied parity checks for each of the H matrix layers.

Abstract: The present inventions are related to systems and methods for decoding data in an LDPC layer decoder for LDPC codes with overlapped circulants.

Abstract: Methods and structure for determining compatibility between a pair of SAS devices for support of super-standard features of the devices. Features and aspects hereof provide for exchange of information between a first and second SAS device using SAS protocol in non-standard manners. The exchanges are designed to exchange information between compatible, enhanced device without causing protocol violation errors in either the first or second devices. The information exchanged represents super-standard features supported by each device. Mutually supported super-standard features are enabled for further communications between the devices. If no super-standard features are mutually supported or if the second device is non-enhanced, no super-standard features are enabled in further communications between the devices.

Abstract: A channel equalization scheme is provided. A linear equalizer using a continuous-time linear equalization and a decision feedback equalizer using a discrete-time decision feedback equalization are integrated together from a hybrid receiver equalizer. The continuous-time linear equalization scheme and the discrete-time decision feedback equalization scheme are blended using a joint adaptation algorithm to form an equalization scheme for inter-symbol interference cancellation in the hybrid receiver equalizer. The hybrid receiver equalizer controls crosstalk while maintaining signal bandwidth and linearity of a signal by the high-order high frequency roll-off of the linear equalizer used. Using this configuration, the hybrid receiver equalizer eliminates the need for adaptive bandwidth controller used in conventional low-pass receiver equalization schemes. The hybrid receiver equalizer can be used in receivers for dual-speed simultaneous transmission on the same physical link.

Abstract: The disclosure is directed to a system and method of a system and method for determining fundamental bit cell duration of a data record, which can be used for pattern-dependent write (PDW) current control. According to various embodiments of the disclosure, at least a first portion of a data record is fed through a plurality of delay units. A binary output of each delay unit is stored in at least one register when the delay units have received the first portion of the data record. The register contents are then decoded to determine fundamental bit cell duration of the data record based upon the stored binary outputs.

Abstract: Described embodiments recover timing and data information from a signal received via a communication channel. An analog-to-digital converter (ADC) operating at a baud rate of the communication channel generates an actual ADC value corresponding to each bit sample of the received signal. A fast symbol estimation module estimates, based on the actual ADC value, a bit value corresponding to each bit sample. The fast symbol estimation module operates at a digital clock rate. The estimated bit values are provided to a timing recovery module. An ADC reconstruction module, based on a first number of pre-cursor estimated bit values, an estimated cursor bit value, and a second number of post-cursor estimated bit values, generates a reconstructed ADC value corresponding to each bit sample. Based on the reconstructed ADC values, the estimated bit values, and the actual ADC values, a corrected bit value is generated for each bit sample.

Abstract: A high availability DAS system uses a solid state cache to provide near active-active performance in a DAS duster, while retaining the implementation simplicity of active-passive or dual active system. Each node in the duster may include a solid state cache that stores hot I/O in an active-active mode, which allows the data to be read from or written to the underlying dual-active or active/passive DAS RAID system only when access to the “hot Region” cools down or in the case of Cache Miss. The hot I/O data includes hot read data that accumulated dynamically regardless of ownership of the drives where the hot read data is permanently stored. The hot I/O data also includes hot write data that is mirrored across the solid state cache memories to avoid potential dirty write data conflicts and also to provide High Availability in case of server failures.