Abstract: A digital signal processor includes analog to digital converters to convert an analog voltage to digital voltage in unit intervals of an analog signal. A decision feedback equalizer (DFE) determines a first level of a digital sum of a digital voltage in a first UI and digital voltages of adjacent UIs (taps). The DFE identifies predetermined sequences of levels of consecutive UIs that include the first level and selects one of the predetermined sequences to decode digital data encoded in the analog signal in the UI. The DSP may be programmable to include taps from UIs that may affect the first UI. The predetermined sequences may include levels of the digital sums of consecutive UIs of the analog signal. The predetermined sequences may be identified in a look-up table based on the first level.

Abstract: A time-interleaved SAR-ADC employs calibrated SAR-ADC circuits to convert sampled voltage levels into serial digital data. Variable delay clock circuits synchronize clock signals received at the respective SAR-ADCs to sampling points of analog serial data. IC and environmental fluctuations cause delay in the variable delay clock circuits to skew the clock signals. A calibrated SAR-ADC detects changes to the delays in the variable delay clock circuits. By delaying a first clock signal in the variable delay clock circuit, and comparing a phase of the delayed clock signal to a phase-shifted clock signal having a known phase shift relative to the first clock signal, a change in the delay of the variable delay clock circuit can be detected as a phase difference. Based on an indication of a phase difference, a delay control signal is generated to control the delay in the variable delay clock.

Abstract: Providing memory bandwidth compression in chipkill-correct memory architectures is disclosed. In this regard, a compressed memory controller (CMC) introduces a specified error pattern into chipkill-correct error correcting code (ECC) bits to indicate compressed data. To encode data, the CMC applies a compression algorithm to an uncompressed data block to generate a compressed data block. The CMC then generates ECC data for the compressed data block (i.e., an “inner” ECC segment), appends the inner ECC segment to the compressed data block, and generates ECC data for the compressed data block and the inner ECC segment (i.e., an “outer” ECC segment). The CMC then intentionally inverts a specified plurality of bytes of the outer ECC segment (e.g., in portions of the outer ECC segment stored in different physical memory chips by a chipkill-correct ECC mechanism). The outer ECC segment is then appended to the compressed data block and the inner ECC segment.

Abstract: Providing memory bandwidth compression in chipkill-correct memory architectures is disclosed. In this regard, a compressed memory controller (CMC) introduces a specified error pattern into chipkill-correct error correcting code (ECC) bits to indicate compressed data. To encode data, the CMC applies a compression algorithm to an uncompressed data block to generate a compressed data block. The CMC then generates ECC data for the compressed data block (i.e., an “inner” ECC segment), appends the inner ECC segment to the compressed data block, and generates ECC data for the compressed data block and the inner ECC segment (i.e., an “outer” ECC segment). The CMC then intentionally inverts a specified plurality of bytes of the outer ECC segment (e.g., in portions of the outer ECC segment stored in different physical memory chips by a chipkill-correct ECC mechanism). The outer ECC segment is then appended to the compressed data block and the inner ECC segment.

Abstract: A dual in-line memory module (DIMM) supporting storage of a data indicator(s) in an error correcting code (ECC) storage unit dedicated to storing an ECC. The DIMM is configured to provide a burst ECC storage unit striped in a burst data storage unit. The DIMM is configured to stripe a received burst data word across a burst data word storage unit at a write data address for a write operation. The DIMM is also configured to stripe a received burst ECC word for the burst data word across the burst ECC storage unit at the write data address in fewer bits than a number of data bit cells in the burst ECC storage unit. In this manner, the DIMM can store at least one data indicator for a burst data word in an extra, leftover bit(s) in the burst ECC storage unit.

Abstract: Providing memory bandwidth compression using back-to-back read operations by compressed memory controllers (CMCs) in a central processing unit (CPU)-based system is disclosed. In this regard, in some aspects, a CMC is configured to receive a memory read request to a physical address in a system memory, and read a compression indicator (CI) for the physical address from error correcting code (ECC) bits of a first memory block in a memory line associated with the physical address. Based on the CI, the CMC determines whether the first memory block comprises compressed data. If not, the CMC performs a back-to-back read of one or more additional memory blocks of the memory line in parallel with returning the first memory block. Some aspects may further improve memory access latency by writing compressed data to each of a plurality of memory blocks of the memory line, rather than only to the first memory block.

Abstract: A dual in-line memory module (DIMM) supporting storage of a data indicator(s) in an error correcting code (ECC) storage unit dedicated to storing an ECC. The DIMM is configured to provide a burst ECC storage unit striped in a burst data storage unit. The DIMM is configured to stripe a received burst data word across a burst data word storage unit at a write data address for a write operation. The DIMM is also configured to stripe a received burst ECC word for the burst data word across the burst ECC storage unit at the write data address in fewer bits than a number of data bit cells in the burst ECC storage unit. In this manner, the DIMM can store at least one data indicator for a burst data word in an extra, leftover bit(s) in the burst ECC storage unit.

Abstract: A method for handling speculative access requests for a storage device in a computer system is provided. The method includes the steps of providing a speculative access threshold corresponding to a selected percentage of the total number of accesses to be speculatively issued, and intermixing demand accesses and speculative accesses in accordance with the speculative access threshold. In another embodiment, a method for reducing data access latency experienced by a user in a computer network is provided. The method includes the steps of providing a web page comprising a link to a data file stored on a database connected to the computer network, selecting a speculative access threshold corresponding to a selected percentage of data accesses which are to be speculatively provided to the user, and speculatively providing the data file in accordance with the speculative access threshold.

Abstract: Computer memory management systems and methods are provided in which data block buffering and priority scheduling protocols are utilized in compressed memory systems to mask the latency associated with memory reorganization work following access to compressed main memory. In particular, data block buffers and priority scheduling protocols are implemented to delay and prioritize memory reorganization work to allow resources to be used for serving new memory access requests and other high priority commands.

Abstract: A system and method for handling speculative read requests for a memory controller in a computer system are provided. In one example, a method includes the steps of providing a speculative read threshold corresponding to a selected percentage of the total number of reads that can be speculatively issued, and intermixing demand reads and speculative reads in accordance with the speculative read threshold. In another example, a computer system includes a CPU, a memory controller, memory, a bus connecting the CPU, memory controller and memory, circuitry for providing a speculative read threshold corresponding to a selected percentage of the total number of reads that can be speculatively issued, and circuitry for intermixing demand reads and speculative reads in accordance with the speculative read threshold.

Abstract: A system and method for handling speculative read requests for a memory controller in a computer system are provided. In one example, a method includes the steps of providing a speculative read threshold corresponding to a selected percentage of the total number of reads that can be speculatively issued, and intermixing demand reads and speculative reads in accordance with the speculative read threshold. In another example, a computer system includes a CPU, a memory controller, memory, a bus connecting the CPU, memory controller and memory, circuitry for providing a speculative read threshold corresponding to a selected percentage of the total number of reads that can be speculatively issued, and circuitry for intermixing demand reads and speculative reads in accordance with the speculative read threshold.

Abstract: A method for handling speculative access requests for a storage device in a computer system is provided. The method includes the steps of providing a speculative access threshold corresponding to a selected percentage of the total number of accesses to be speculatively issued, and intermixing demand accesses and speculative accesses in accordance with the speculative access threshold. In another embodiment, a method for reducing data access latency experienced by a user in a computer network is provided. The method includes the steps of providing a web page comprising a link to a data file stored on a database connected to the computer network, selecting a speculative access threshold corresponding to a selected percentage of data accesses which are to be speculatively provided to the user, and speculatively providing the data file in accordance with the speculative access threshold.

Abstract: A method and apparatus implement memory accesses to a memory using an open page mode with data prefetching. A central processor unit issues memory commands. A memory controller receiving the memory commands, identifies a data prefetching command. The memory controller checks whether a next sequential line for the identified prefetch command is within the page currently being accessed, and responsive to identifying the next sequential line being within the current page, the current command is processed and the current page left open.

Abstract: Computer memory management systems and methods are provided in which data block buffering and priority scheduling protocols are utilized in compressed memory systems to mask the latency associated with memory reorganization work following access to compressed main memory. In particular, data block buffers and priority scheduling protocols are implemented to delay and prioritize memory reorganization work to allow resources to be used for serving new memory access requests and other high priority commands.

Abstract: A network processor useful in network switch apparatus and methods of operating such a processor in which data flow handling and flexibility is enhanced by the cooperation of a plurality of interface processors formed on a semiconductor substrate. The interface processors provide data paths for inbound and outbound data flow and operate under the control of instructions stored in an instruction store formed on the semiconductor substrate.

Abstract: A system, method and computer program features of the present invention, relate to verification or simulation of a design using a behavioral model structure for use in a Client/Server configuration. A physical part presents the external interface, and a functional procedural part which is comprised of at least one VHDL process. A testcase is a set of procedure calls written in VHDL. The present invention describes the architecture and implementation of a client/server behavioral model and procedural approach for testcase development which results in significant gain in productivity, quality of logic verification, and portability.

Abstract: A method and system for queueing data within a data storage device including a set of storage blocks each having an address, a pointer field, and a data field. This set of storage blocks comprises a linked list of associated storage blocks and also a free pool of available storage blocks. The storage device further includes a tail register for tracking an empty tail block from which a data object is enqueued into the linked list. A request to enqueue a data object into the linked list is received within the data storage system. In response to the data enqueue request, an available storage block from the free pool is selected and associated with the tail register. A single write operation is then required to write the data object into the data field of a current tail block and to write the address of the selected storage block into the pointer field of the current tail block, such that the selected storage block becomes a new tail block to which the tail register points.

Abstract: A bandwidth conserving queue manager for a FIFO buffer is provided, preferably on an ASIC chip and preferably including separate DRAM storage that maintains a FIFO queue which can extend beyond the data storage space of the FIFO buffer to provide additional data storage space as needed. FIFO buffers are used on the ASIC chip to store and retrieve multiple queue entries. As long as the total size of the queue does not exceed the storage available in the buffers, no additional data storage is needed. However, when some predetermined amount of the buffer storage space in the FIFO buffers is exceeded, data are written to and read from the additional data storage, and preferably in packets which are of optimum size for maintaining peak performance of the data storage device and which are written to the data storage device in such a way that they are queued in a first-in, first-out (FIFO) sequence of addresses. Preferably, the data are written to and are read from the DRAM in burst mode.

Abstract: The ability of network processors to move data to and from dynamic random access memory (DRAM) chips used in computer systems is enhanced in several respects. In one aspect of the invention, two double data rate DRAMS are used in parallel to double the bandwidth for increased throughput of data. The movement of data is further improved by setting 4 banks of full ‘read’ and 4 banks of full ‘write’ by the network processor for every repetition of the DRAM time clock. A scheme for randomized ‘read’ and ‘write’ access by the network processor is disclosed. This scheme is particularly applicable to networks such as Ethernet that utilize variable frame sizes.