Abstract: A RAID storage system serializes data blocks to be stored in a RAID storage array and uses a primary map table and a number of secondary map tables to relate host addresses to logical block addresses in the storage array. Secondary map tables and other metadata can be cached from the storage array. The dual or two-tier map scheme and metadata caching promote scalability.

Abstract: Aspects of the disclosure pertain to methods and systems that are configured to handle excessive read noise in soft read systems. In an implementation, a method includes determining a number of unexpected patterns of a soft read of a memory cell after a soft decoding failure. The method also includes determining whether the number of unexpected patterns is greater than a threshold number of unexpected patterns. When it is determined that the number of unexpected patterns is greater than the threshold number of unexpected patterns, the method at least one of: performing at least one more soft read of the memory cell with a larger read voltage spacing than an initial read that produced the soft decoding failure; and discarding a result of one or more soft reads of the memory cell and utilizing a remainder of results of respective other soft reads of the memory.

Abstract: A system includes a processor configured to read information from a plurality of memory cells. The processor initiates a first read of raw data from a group of memory cells using a first reference voltage. The processor also initiates a second read of raw data from the group of memory cells using a second reference voltage different from the first reference voltage. The processor further compares the first read to the second read to identify memory cells read with a bit value that changes between the first and second reads. The processor also assigns the memory cells read with a bit value that changes between the first and second reads to a region associated with the second reference voltage. The processor further counts the number of cells read with a bit value that changes to generate a histogram corresponding to soft information for the group of memory cells.

Abstract: Methods and structure for detecting that arbitration is delaying discovery. One embodiment is a Serial Attached Small Computer System Interface (SAS) expander. The SAS expander includes multiple SAS ports, a port monitor, and a controller. The port monitor is able to track physical link events during arbitration for at least one of the ports while discovery is in progress at the expander, and to detect based on the physical link events that arbitration is delaying discovery. The controller is able to prioritize discovery requests at the expander responsive to detecting that arbitration is delaying discovery.

Abstract: A storage controller coupled to a host computer is dynamically configured by a device driver executing in the host computer. The storage controller manages a logical volume for the host using a set of flash-based storage devices arranged as a redundant array of inexpensive disks (RAID). The device driver identifies a RAID type for the logical volume and a queue depth from a stream of I/O commands. For a logical volume in RAID 0, the device driver compares the queue depth to a threshold value and configures the storage controller to process the stream of I/O commands with a first path or an alternative path based on a result of the comparison. For a logical volume in RAID 5, the device driver performs a similar comparison and uses the result to direct the storage controller to use a write back or a write through mode of operation.

Abstract: Systems and methods provide zone management for devices in a Serial Attached Small Computer System Interface (SAS) topology. In one embodiment, a zone management device stores a zone map that identifies an initial zone of a device in the topology. The management device detects changes in the topology, and identifies a current zone of the device subsequent to the change in the topology. The management device compares the zone map for the device to the current zone to identify a change in the zone of the device, and generates a message for an expander in the topology based on the change in the zone. The management device then transmits the message to the expander to restore the zone of the device to the initial zone.

Abstract: An apparatus includes an error correction code circuit and an error correction code selection circuit. The error correction code circuit may be configured to encode and decode data using any of a plurality of error correction codes. The error correction code selection circuit may be configured to control which of the plurality of error correction codes is used by the error correction code circuit to encode and decode data responsive to one or more reliability statistics and predetermined data characterizing distribution properties of each of the plurality of error correction codes.

Abstract: Systems and method relating generally to data processing, and more particularly to systems and methods for scaling messages in a data decoding circuit.

Abstract: An apparatus comprising a memory and a controller. The memory is configured to process a plurality of read/write operations. The memory comprises a plurality of memory unit granularities each having a size less than a total size of the memory. The controller is configured to process a plurality of I/O requests to the memory units of the memory that are not marked as bad on a memory unit list. The controller is configured to track a plurality of bad blocks of the memory. The controller is configured to determine which of the memory units to mark as bad based on a test of whether a unit of memory larger than a block of the memory has failed. The test is based on a threshold of the bad blocks in the unit of memory.

Abstract: An apparatus includes a plurality of memory dies and a controller. The controller may be communicatively coupled to the plurality of memory dies and configured to utilize multiple copies of a root record containing system data during a boot-up process. The multiple copies of the root record are stored using at least two of the plurality of memory dies.

Abstract: An apparatus for measuring cross-talk in an array reader magnetic storage system includes an array reader with multiple read heads operable to read data from a magnetic storage medium, a first preamplifier connected to a first read head, a second preamplifier connected to a second read head, and a cross-talk measurement circuit connected to the first preamplifier and to the second preamplifier, operable to measure cross-talk between a first signal from the first read head and a second signal from the second read head.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for processing skew tolerant processing of data derived from multiple read heads.

Abstract: Described embodiments provide a magnetic mass storage device with a system clock phase-locked to servo address marks on the magnetic disk. A head sequentially reads multiple adjacent servo address marks in a spiral track of servo address marks. When a servo address mark detector detects a mark, the count value of a counter driven by the system clock is sampled and held by a latch. A system clock synthesizer calculates differences in value between successively sampled count values from the latch, averages the differences in value to create an average difference value, and normalizes a difference between the average difference value and a target value to create a phase error value. The phase of the system clock is updated using the phase error value.

Abstract: A memory includes a number of storage elements connected to a pair of bit-lines, a bit-line pre-charging circuit, a sense amplifier connected to the pair of bit-lines through a column-select switch, a transition detection circuit connected to an output of the sense amplifier, and a local pre-charge control circuit connected to the transition detection circuit and having a local pre-charge control signal output connected to the bit-line pre-charging circuit.

Abstract: A system is described that analyzes timing of a design and conditionally replaces values of a cell to lower total power within circuit paths having a positive timing margin. The system includes a computing device that includes a memory for storing modules and a processor that is operable to execute the modules. The modules cause the processor to conditionally replace a first semiconductor characteristic with a second semiconductor characteristic associated with a cell in a path of a circuit design and estimating a delay and a slack of the path based upon the first semiconductor characteristic. The modules also cause the processor to determine whether the second semiconductor characteristic causes a timing violation with respect to the path and causes conditional replacement of the second semiconductor characteristic with a third semiconductor characteristic until the timing violation is removed.

Abstract: The disclosure is directed to a system and method of managing memory resources in a communication channel. According to various embodiments, incoming memory slices associated with a plurality of data sectors are de-interleaved and transferred sequentially through a buffer to a decoder for further processing. To prevent buffer overflow or degraded decoder performance, the memory availability of the buffer is monitored, and transfers are suspended when the memory availability of the buffer is below a threshold buffer availability.

Abstract: An apparatus having a processor and an interface to a nonvolatile memory having a plurality of blocks is disclosed. The processor is configured to (i) monitor a number of reads since a respective erase in at least one of the blocks in the nonvolatile memory, (ii) move a page from a first block to a second block in response to the number of reads exceeding a first threshold where the first block is partially programmed and (iii) move the page from the first block to the second block in response to the number of reads exceeding a second threshold where the first block is fully programmed. The first threshold is less than the second threshold.

Abstract: Methods and structure for redirecting writes in Redundant Array of Independent Disks (RAID) systems are provided. One exemplary embodiment is a RAID controller that includes a memory and a control unit. The memory is able to store mapping information that correlates Logical Block Addresses of a RAID volume with physical addresses of storage devices. The control unit is able to generate a request to write volume data to at least one of the physical addresses, to determine that a storage device has failed to complete the request, to alter the mapping information by correlating Logical Block Addresses for the request with physical addresses of a spare storage device, to redirect the request to the spare storage device, and to rebuild remaining Logical Block Addresses that are correlated with the storage device that failed.

Abstract: A data processing system includes a number of processor cores each having a trace interface with an address signal carrying program addresses being executed, a processor core identification circuit connected to the trace interfaces and operable to replace a portion of some of the program addresses with a processor core identification that identifies which of the processor cores provided the program addresses, and an execution trace buffer operable to store the program addresses associated with non-sequential execution in the processor cores. At least some of the program addresses include the processor core identification along with address bits.

Abstract: Methods and systems for reducing memory test time utilizing a serial per march element communicating architecture. A small number of slow speed signals can be configured between a BIST wrapper and a BIST controller to transfer information in accordance with a BIST sequence that includes a number of march elements. An information transfer protocol can be implemented between the BIST wrapper and the BIST controller to transfer Information with respect to each march element that includes a number of BIST operations, address sequencing information, and data pattern. A command register can be loaded utilizing the slow speed signals and slow speed clock and content of the command register can be decoded. An encoded BIST operation can then be executed once for each BIST operation per march element. The serial per march element communicating architecture reduces test time as a communication overhead and a requirement for high speed wires are eliminated.