Patents Assigned to Broadcom
  • Publication number: 20030055631
    Abstract: A method and system are provided for processing an extrapolated signal including a number of consecutive replacement frames. The method comprises attenuating a portion of the extrapolated signal when the extrapolated signal reaches a predetermined duration. The attenuating produces an output signal having an attenuated portion, wherein the output signal includes the number of consecutive replacement frames. Each of the consecutive frames within the attenuated portion is attenuated by applying an attenuation window with a starting magnitude value of approximately 1 and including a unique ending magnitude. The unique ending magnitudes decrease over time.
    Type: Application
    Filed: June 28, 2002
    Publication date: March 20, 2003
    Applicant: Broadcom Corporation
    Inventor: Juin-Hwey Chen
  • Patent number: 6535510
    Abstract: A method of forwarding data in a network switch fabric is disclosed. An incoming data packet is received at a first port of the fabric and a first packet portion, less than a full packet length, is read to determine particular packet information, the particular packet information including a source address and a destination address. An egress port bitmap is determined based on a lookup in a forwarding table and it is determined if the destination address belongs to a trunk group of trunked ports. The incoming data packet is forwarded based on the egress port bitmap, when the destination address does not belong to the trunk group. When the destination address does belong to the trunk group, a particular trunked port of the trunk group is determined and the incoming data packet is forwarded thereto.
    Type: Grant
    Filed: June 19, 2001
    Date of Patent: March 18, 2003
    Assignee: Broadcom Corporation
    Inventors: Mohan Kalkunte, Srinivas Sampath, Daniel Tai, Soma Pullela, Kevin Cameron
  • Patent number: 6535025
    Abstract: A sense amplifier adapted to sense an input signal on global bitlines, having an amplifier offset cancellation network and an offset equalization network. The amplifier offset cancellation network mitigates an inherent offset signal value, a dynamic offset signal value, or both, yet produces a residual offset signal value, which is substantially eliminated by the offset equalization network. The sense amplifier also can include an isolation circuit to isolate the sense amplifier from the corresponding global bitlines when the sense amplifier is unused. Also, a charge-sharing circuit is used to share charge between the bitlines when the sense amplifier is activated, thus producing a limited voltage swing on the bit lines. The sense amplifier uses an amplifier offset cancellation network having multiple precharge-and-balance transistors, and an offset equalization network having at least one balancing transistor.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: March 18, 2003
    Assignee: Broadcom Corp.
    Inventors: Esin Terzioglu, Morteza Cyrus Afghahi
  • Patent number: 6535036
    Abstract: A conditional clock buffer circuit is disclosed. In one embodiment, a conditional clock buffer circuit includes a precharge circuit, a first transistor and a second transistor coupled to the precharge circuit via the first node and the second node, a third transistor coupled to the first transistor and the second transistor. The first transistor may be activated responsive to a condition external to the clock buffer circuit. When the first transistor is activated, an output clock signal driven by the clock buffer circuit may be inhibited.
    Type: Grant
    Filed: May 1, 2002
    Date of Patent: March 18, 2003
    Assignee: Broadcom Corporation
    Inventor: Daniel W. Dobberpuhl
  • Publication number: 20030048234
    Abstract: An antenna includes a magnetic interface generator that generates a magnetic interface at a center frequency f0. The magnetic interface generator is a passive array of spirals that are deposited on one layer of a multi-layer substrate. The magnetic interface is generated in a plane at a distance Z above the surface of the substrate layer that it is printed on, where the antenna in printed on a second layer of the multi-layer substrate. The distance Z where the magnetic interface is created is determined by the cell size of the spiral array, where the cell size is based on the spiral arm length and the spacing S between the spirals. The center frequency of the magnetic interface is determined by the average track length DAV of the spirals in the spiral array. The spacing S of the spiral array is chosen to project the magnetic interface to the second layer in the multi-layer substrate so as to improve performance of the antenna that printed on the second layer.
    Type: Application
    Filed: August 23, 2002
    Publication date: March 13, 2003
    Applicant: Broadcom Corporation
    Inventors: Nicolaos G. Alexopoulos, Harry Contopanagos, Chryssoula Kyriazidou
  • Publication number: 20030048119
    Abstract: A transition delay matching circuit in which the transition delay of the divided clock signal is substantially the same as the transition delay of the reference clock signal. The transition delay of the divided clock signal is adjusted by reducing the steady state amplitude of the divided clock signal. Apparatuses and methods for matching the transition delays of the divided clock signal and the reference clock signal are disclosed.
    Type: Application
    Filed: July 19, 2002
    Publication date: March 13, 2003
    Applicant: Broadcom Corporation
    Inventor: Kwang Y. Kim
  • Publication number: 20030048847
    Abstract: The present invention provides a buffer architecture and latency reduction mechanism for buffering uncompressed/compressed information. This combination provides for proficient division of the encoding task and quicker through-put time. The invention teaches a single chip digital signal processing device for real time video/audio compression comprising a plurality of processors, including a video input processor, a motion estimation processor, a digital signal processor, and a bitstream processor, wherein processing and transfer of the signals within the device is done in a macroblock-by-macroblock manner. The device can include a multiplexing processor that is comprised of a storage unit which buffers a compressed video bitstream and a processor which retrieves the compressed video bitstream from the storage unit and produces a multiplexed data stream whereby the compressed video bitstream is processed in a pipeline manner.
    Type: Application
    Filed: October 29, 2002
    Publication date: March 13, 2003
    Applicant: Broadcom Corporation
    Inventors: Leonid Yavits, Amir Morad
  • Publication number: 20030051197
    Abstract: The benefits of on-chip self testing are widely recognized and include the capability to test at high operating speed and independently of external test equipment timing and accuracy limitations. However caches present difficulties since for testing purposes they are conventionally regarded as separate RAM and CAM arrays. The disclosed test engine tests the cache as a whole (i.e., RAM, CAM and comparators together). In the test mode, cache writes are absolutely addressable, selecting a particular entry in a particular way-set during each operation using line addressing and common tag data. This enables read operations to access a specific cache line as if absolutely addressable based on only a partial address and the known tag setting.
    Type: Application
    Filed: June 18, 2002
    Publication date: March 13, 2003
    Applicant: Broadcom Corporation
    Inventor: Richard J. Evans
  • Publication number: 20030048115
    Abstract: Method and circuitry for converting a differential logic signal to a single-ended logic signal eliminate slower PMOS transistors and speed up the conversion process. In specific embodiments differential logic signals of the type employed in, for example, current-controlled complementary metal-oxide-semiconductor (C3MOS) logic are converted to single-ended rail-to-rail CMOS logic levels using a differential pair of NMOS transistors with resistors as load devices and an NMOS current source transistor that provides dynamically adjusted tail current.
    Type: Application
    Filed: October 7, 2002
    Publication date: March 13, 2003
    Applicant: BROADCOM CORPORATION
    Inventor: Namik Kocaman
  • Patent number: 6531923
    Abstract: A low voltage current mirror circuit (also referred to as a bias circuit) for establishing a plurality of bias voltages from an input current supplied to an input terminal of the circuit includes an input stage, a current stage connected to the input stage, a feedback stage connected to the current stage, a reference bias stage connected to the feedback stage and the current stage. The circuit establishes first and second bias voltages suitable for biasing current sources of a first type, and third and fourth bias voltages suitable for biasing current sources of a second type complementary to the first type. The bias voltages track the input current over variations in at least one of process, temperature and power supply voltage.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: March 11, 2003
    Assignee: Broadcom Corporation
    Inventor: Lawrence M. Burns
  • Patent number: 6531973
    Abstract: The present invention is directed to a sigma-delta digital to analog converted (DAC) including a digital-sigma delta modulator, a decimation filter, and a multi-bit DAC. The digital sigma-delta modulator receives a digital input signal and produces a quantized digital signal therefrom. The decimation filter receives the quantized digital signal and produces a decimated digital signal therefrom. The multi-bit DAC receives the decimated digital signal and produces an analog output signal therefrom. The analog output signal is representative of the digital input signal.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: March 11, 2003
    Assignee: Broadcom Corporation
    Inventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller
  • Patent number: 6531915
    Abstract: Methods and apparatus for improving the current matching within current mirror circuits in applications such as low voltage integrated circuits. Embodiments of the present invention attempt to maintain the proper current ratio between reference and output supplies by adjusting the reference output of the current mirror. An existing reference voltage on the output side of the mirror can be used or a reference voltage can be created to be used for the voltage regulation of the reference side of the current mirror.
    Type: Grant
    Filed: April 23, 2002
    Date of Patent: March 11, 2003
    Assignee: Broadcom Corporation
    Inventors: Arya Reza Behzad, Frank Wayne Singor
  • Publication number: 20030042984
    Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.
    Type: Application
    Filed: July 8, 2002
    Publication date: March 6, 2003
    Applicant: Broadcom Corporation
    Inventors: Shervin Moloudi, Maryam Rofougaran
  • Publication number: 20030043768
    Abstract: Methods and apparatus for acquiring and verifying a code used by a base station. Acquisition time is reduced and circuitry simplified by performing Phase I and Phase II acquisitions in series, but in parallel with Phase III acquisition and verification, which are done in series. Phase III code acquisition is done by despreading the input signal using each of the possible codes in a code group. An estimation of the frequency offset between the base station and the terminal's local reference is used to correct the phase of the despread signals, which are coherently and non-coherently integrated. The largest accumulated value corresponds to the code used by the base station. The code is verified by despreading the received signal, applying a frequency correction, and demodulating. The demodulated output is a series of symbols, and a count of these symbols verifies the acquired code.
    Type: Application
    Filed: August 26, 2002
    Publication date: March 6, 2003
    Applicant: Broadcom Corporation
    Inventors: Li Fung Chang, Nelson Sollenberger, Baoguo Yang
  • Publication number: 20030043077
    Abstract: A magnetic interface generator generates a magnetic interface at a center frequency f0. The magnetic interface generator is a passive array of spirals that are deposited on a substrate surface. The magnetic interface is generated in a plane at a distance Z above the surface of the substrate. The distance Z where the magnetic interface is created is determined by the cell size of the spiral array, where the cell size is based on the spiral arm length and the spacing S between the spirals. The center frequency of the magnetic interface is determined by the average track length DAV of the spirals in the spiral array. In embodiments, the spiral array is one sub-layer in a multi-layer substrate. The spacing S of the spiral array is chosen to project the magnetic interface to another layer in the multi-layer substrate so as to improve performance of a circuit in the plane of the magnetic interface.
    Type: Application
    Filed: August 23, 2002
    Publication date: March 6, 2003
    Applicant: Broadcom Corporation
    Inventors: Nicolaos G. Alexopoulos, Harry Contopanagos, Chryssoula Kyriazidou
  • Publication number: 20030043948
    Abstract: Digital data signals at a variable input frequency are converted by a numerically controlled oscillator and an interpolator to a signal at a fixed output sampling frequency. The conversion of the variable input frequency to the fixed output sampling frequency may be by a factor other than an integer. The interpolated digital data signals at the fixed output sampling frequency are then modulated into a pair of trigonometric signals at a programmable carrier frequency, one signal having a cosine function and the other signal having a sine function. The modulated signals at the fixed output sampling frequency are then combined to create a modulated signal at a carrier frequency determined by the frequency of the sine and cosine signals. The modulated signal is sampled at the fixed output sampling frequency and converted to a corresponding analog signal using a digital-to-analog converter.
    Type: Application
    Filed: October 17, 2002
    Publication date: March 6, 2003
    Applicant: Broadcom Corporation
    Inventors: Henry Samueli, Joseph J. Laskowski
  • Publication number: 20030044007
    Abstract: Methods and apparatus are provided for improving ARC4 processing in a cryptography engine. A multiple ported memory can be used to allow pipelined read and write access to values in memory. Coherency checking can be applied to provide that read-after-write and write-after-write consistency is maintained. Initialization of the memory can be improved with a reset feature occurring in a single cycle. Key shuffle and key stream generation can also be performed using a single core.
    Type: Application
    Filed: December 20, 2001
    Publication date: March 6, 2003
    Applicant: Broadcom Corporation
    Inventor: Donald P. Matthews
  • Patent number: 6530015
    Abstract: A method and system of executing computer instructions is described. Each instruction defines first and second operands and an operation to be carried out on said operands. Each instruction also contains an address field of a predetermined bit length which identifies a test register holding a plurality of test bits greater than the predetermined bit length. The test register holds a test code defining a test condition. The test condition is checked against at least one condition code and the operation is selectively carried out in dependence on whether the condition code satisfies the test condition. In one embodiment, the condition codes are set on a lane-by-lane basis for packed operands.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: March 4, 2003
    Assignee: Broadcom Corporation
    Inventor: Sophie Wilson
  • Patent number: 6529935
    Abstract: A graphics display system integrated circuit is used in a set-top box for controlling a television display. The graphics display system processes analog video input, digital video input, and graphics input. The system incorporates a unified memory architecture that is shared by the graphics system, a CPU, and other peripherals. The unified memory architecture uses real time scheduling to service tasks. Critical instant analysis is used to find a schedule for memory usage that does not affect memory requirements of real time tasks while at the same time servicing non-real-time tasks as needed.
    Type: Grant
    Filed: November 14, 2000
    Date of Patent: March 4, 2003
    Assignee: Broadcom Corporation
    Inventors: Alexander G. MacInnis, Chengfuh Jeffrey Tang, Xiaodong Xie, James T. Patterson, Greg A. Kranawetter
  • Patent number: 6530012
    Abstract: A method of executing instructions in a computer system on operands containing a plurality of packed objects in respective lanes of the operand is described. Each instruction defines an operation and contains a condition setting indicator settable independently of the operation. The status of the condition setting indicator determines whether or not multibit condition codes are set. When they are to be set, they are set depending on the results of carrying out the operation for each lane.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: March 4, 2003
    Assignee: Broadcom Corporation
    Inventor: Sophie Wilson