Xyratex Technology Limited

Napatech A/s

International Business Machines Corporation

Kathryn E Rickard

Christopher Bloxham

William Mark Dries

Roderick Michael West

Richard J Grupp

Paul C Millard

In conventional systems the CPU is altered after a data frame has been received and the packet stored in a host buffer. This interrupts normal operation of the CPU and applications, which is determined to systems performance. The invention relates to a method of transferring data from a network to a host using a network analyzer card, where a plurality of data frames from a network link is received and a descriptor is added to the frame. The descriptor includes data about the frame; each data frame and its or their attached descriptor is transferred to a host memory.

Method of transferring data implying a network analyser card

A data merge unit is provided for providing an interleaved data stream, the data stream including data frames received on two or more input channels, wherein data frames from each of the two or more input channels are arranged in time-slots of the interleaved data stream. The data merge unit comprises an input unit to receive data frames from two or more input channels, a frame merge buffer arranged to receive data frames from the two or more input channels via the input unit and store said data frames; and, an output generator to generate the interleaved data stream, the output generator being configured to select complete data frames from the frame merge buffer and arrange said complete data frames in the interleaved data stream.

Data merge unit, a method of producing an interleaved data stream, a network analyser and a method of analysing a network

A direct memory access controller includes a source memory controller for controlling a source memory, a destination bus controller for controlling the transfer of data to a destination memory, a first-in-first-out memory buffer for receiving data from the source memory, and a filter connected upstream of the first-in-first-out memory buffer for comparing the source memory data to a filter criterion and passing to the first-in-first-out memory buffer only that data which matches the filter criterion.

Direct memory access controller and method of filtering data during data transfer from a source memory to a destination memory

A method and system for partial reassembly of data frames reconstructed from data cells received from a network data stream includes partially reassembling the header cells and the last cell of each frame and passing the remainder of data frame cells to a capture buffer in an unassembled state. Since the partially reassembled data frames include only a subset of each frame, they can be processed at the full line-rate of the network data stream without causing an overflow. The cells in the partially reassembled frames are only those cells required for functions that must be performed at the full line rate.

Frame reassembly in an ATM network analyzer

Video subsystem power savings are achieved by shutting off power to unused subcircuits during blanking. Digital circuitry within the video subsystem not used during blanking is shut-down by turning off the clock thereto. Analog circuitry within a digital to analog converter is shut-down by turning off the constant current reference thereto. A functional unit containing digital circuitry within a serializer palette digital to analog converter (SPDAC) is shut-down by turning off the clock thereto during system operation in a mode where the functional unit is not utilized. A computer system having a monochrome display saves power by shutting off DAC digital circuitry clocks and DAC analog circuitry constant current references of all DACs but one. A portable computer with a liquid crystal display (LCD), a SPDAC for driving an external display and a LCD controller, saves power by shutting down video subsystem functional units and analog DAC circuitry not used for driving the LCD. Digital circuitry within the LCD controller is shut-down when an external display is being driven. In a portable computer operating in a SUSPEND state, video subsystem functional units are shut-down.

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Romsey, United Kingdom

Kathryn E Rickard