Abstract: A method of processing a data stream through a buffer is performed in accordance with a write clock and a read clock. The buffer has a plurality of sequentially numbered storage cells. The method includes the steps of selecting an initial preload value, with the selecting step including determining a product of the maximum frequency offset between the write and read clocks, and a maximum time between arbitrary symbols in the data stream. The storage cells then receive data units in response to a write pointer. Data units are then provided from the storage cells in response to a read pointer.
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:
Grant
Filed:
October 19, 2000
Date of Patent:
June 19, 2007
Assignee:
Broadcom Corporation
Inventors:
Hooman Darabi, Ahmadreza Rofougaran, Shahla Khorram, Brima Ibrahim
Abstract: An instruction set for a computer is described which includes instructions having a common predetermined bit length. That predetermined bit length can define a single operation or two independent operations. The instruction includes designated bits at predetermined bit locations which identify whether the instruction is a long instruction or a dual operation instruction.
Abstract: A divider for a local oscillator (LO) generator system of a phase locked loop (PLL) in a transceiver chip. The divider includes at least one divider unit. Each divider unit includes a frequency divider unit for receiving an input signal having an input frequency and for outputting an output signal having an output frequency which is approximately one half of the input frequency. Each divider unit also includes a resistor bank coupled between a voltage source and the frequency divider unit, and a current stirring unit for supplying current to the frequency divider unit. The resistance of the resistor bank and a magnitude of the current supplied by the current stirring unit are variable depending on the input frequency.
Abstract: An apparatus for converting a signal from a first analog format to a second analog format. The apparatus has an input port, a first converter, filters, first mixers, second converters, and an output port. The input port is configured to receive the signal. The signal has the first analog format. In an embodiment, the first analog format complies with the SCTE 40 2003 technical standard. In an embodiment, the second analog format is a conventional analog format. The first converter is coupled to the port and is configured to convert the signal to a first digital format. The filters are coupled to the first converter and configured to isolate a first channel of the signal from a second channel of the signal. The first mixers are coupled to the filters and configured to expand the first channel and the second channel to a second digital format. The second converters are coupled to the first mixers and configured to convert the first channel and the second channel to the second analog format.
Type:
Grant
Filed:
May 27, 2004
Date of Patent:
June 19, 2007
Assignee:
Broadcom Corporation
Inventors:
Richard Nelson, Brian Sprague, Donald McMullin, Richard Prodan, Pieter Vorenkamp
Abstract: A method for configuring a multiple input multiple output (MIMO) wireless communication begins by generating a first preamble for a first antenna of the MIMO communication, wherein the first preamble includes a carrier detect field, a first channel select field, a first signal field, and a second signal field. The method continues by generating a second preamble for at least one other antenna of the MIMO communication, wherein the second preamble includes the carrier detect field, a plurality of channel select fields, and the second signal field. The method continues by simultaneously transmitting the carrier detect field via the first antenna and the least one other antenna. The method continues by transmitting the first channel select field and the first signal field via the first antenna.
Type:
Grant
Filed:
October 26, 2004
Date of Patent:
June 19, 2007
Assignee:
Broadcom Corporation
Inventors:
Christopher J. Hansen, Jason A. Trachewsky, R. Tushar Moorti, Matthew J. Fischer, Christopher Young
Abstract: An output stage protection system for protecting NMOS devices in an integrated circuit (IC) output stage during normal operations and power up/power down. In an embodiment, the output stage includes a pair of relatively low voltage NMOS devices coupled to a current source and IC core outputs. A first pair of relatively high voltage NMOS devices is coupled to the relatively low voltage pair and a biasing circuit. A second pair of relatively high voltage NMOS devices is coupled to a resistor, the first pair, and first and second output nodes, respectively. One or more diodes are coupled in series between the first and second output nodes and the resistor. In an embodiment, the output stage protection system protects NMOS devices in the output stage from electrostatic discharge (ESD). Input/output (I/O) pad ESD protection circuits are coupled to the I/O pads and include a clamp coupled to a local net.
Abstract: A dynamic priority scheme is provided that uses information including the status of the target and data availability in deciding which PCI master should be assigned ownership of the bus. The target uses delayed transactions to complete a read access targeted to it. The target also integrates a buffer management scheme, in one embodiment an input/output cache, for buffer management. The present invention optimizes the performance and utilization of the PCI bus.
Type:
Grant
Filed:
October 12, 2004
Date of Patent:
June 19, 2007
Assignee:
Broadcom Corporation
Inventors:
Sujith K. Arramreddy, Appanagari Raghavendra
Abstract: A memory cell for reducing the cost and complexity of modifying a revision identifier (ID) or default register values associated with an integrated circuit (IC) chip, and a method for manufacturing the same. The cell, which may be termed a “Meta-Memory Cell” (MMCEL), is implemented on metal layers only and utilizes a dual parallel metal ladder structure that traverses and covers each metal and via layer from the bottom to the top of the metal layer structure of the chip. One of the metal ladders is connected to a power supply at the bottom metal layer, corresponding to a logic 1, and another metal ladder is connected to ground at the bottom metal layer, corresponding to a logic 0. The output of the MMCEL can thus be inverted at any metal or via layer and can be inverted as often as required. Significant cost savings are achieved because a revision ID or default register bits may be modified by altering only those metal layers where design changes are necessary.
Type:
Application
Filed:
February 2, 2007
Publication date:
June 14, 2007
Applicant:
Broadcom Corporation
Inventors:
Manolito Catalasan, Vafa Rakshani, Edmund Spittles, Tim Sippel, Richard Unda
Abstract: A method and apparatus to provide a variable voltage source for calibrating an analog-to-digital converter (ADC) by efficient decoding of a multiplexer control signal. A multiplexer efficiently decodes the multiplexer control signal to provide a variable calibration source that has a high-accuracy digital control. The multiplexer senses the multiplexer control signal and varies only one of a multiplexer first output and a multiplexer second output for a one-bit change in a least significant bit of the multiplexer control signal. Calibrating the ADC with the variable calibration source increases the accuracy of the ADC.
Abstract: In an embodiment, an analog to digital converter (ADC) has a dynamic power circuit. The ADC has a track-and-hold circuit with an output and a track mode. The ADC also has a comparator with an input. A preamplifier is coupled between the track-and-hold output and the comparator input. At least one of a preamplifier current and a comparator current are limited during the track mode to reduce ADC power consumption.
Abstract: In an embodiment, an apparatus and method reduces a calibration settling time in an analog-to-digital converter (ADC). The ADC has a reference voltage supply. The reference voltage supply has an output. A filter capacitor is coupled to the reference voltage supply output. An isolation transistor is series-coupled between the filter capacitor and ground. The isolation transistor isolates the filter capacitor during calibration of the ADC.
Abstract: A low pass filter includes a switchable resistor bank, a gain stage, and a capacitor bank. The resistors and capacitors switched into the circuit determine the cutoff frequency of the low pass filter. The frequency programmability may be obtained using the switchable resistor bank and may be implemented as a parallel bank of binary weighted resistors. Further programmability may be obtained using the switchable capacitor bank in conjunction with the switchable resistor bank. The resistor and capacitor processes in a semiconductor wafer are sufficiently accurate and repeatable so as to minimize any necessary calibration.
Type:
Application
Filed:
November 27, 2006
Publication date:
June 14, 2007
Applicant:
Broadcom Corporation
Inventors:
Francesco Gatta, Rajeshmohan Radhamohan
Abstract: A conversion circuit increases a gain of an analog-to-digital converter (ADC) preamplifier by minimizing a common mode offset voltage between an input signal and a reference signal. The feedback controller circuit calibrates an input common mode voltage to mitigate a common mode offset voltage. Reduction of the common mode offset voltage increases the gain of the ADC preamplifier. In an example, the method is executed during a hold phase of a track-and-hold circuit that transmits the input signal to the ADC.
Abstract: This invention describes an apparatus and method to improve the performance of a decision feedback equalizer (DFE) for time-varying multi-path channels. For minimum-phase channels, the equalization is performed in a time-forward manner. For maximum-phase channels, the equalization is performed in a time-reversed manner. More specifically, for maximum-phase channels, the filter coefficients are computed based on the channel estimates reversed in time, and the filtering and equalization operations are performed with the received block of symbols in a time-reversed order. In the context of this invention, the term “minimum-phase channel” implies that the energy of the leading part of the channel profile is greater than the energy of the trailing part. The term “maximum-phase channel” implies that the energy of the leading part of the channel profile is less than the energy of the trailing part.
Abstract: A method and apparatus for fractional-N synthesis includes processing that begins by generating a 1st feedback frequency from the output frequency based on a fixed divider value. The processing continues by generating a 2nd feedback frequency from the output frequency based on a selectable divider value, a modified fractional value of the divider value, and a modified integer value of the divider value. The processing continues by determining whether the fractional value of the divider value is within a range of fractional values. If so, the 1st feedback frequency is used to produce the output. If the fractional portion of the divider value is not within the range of fractional values, the 2nd feedback frequency is used to produce the output frequency.
Type:
Grant
Filed:
December 12, 2001
Date of Patent:
June 12, 2007
Assignee:
Broadcom Corporation
Inventors:
Hung-Ming Chien, Meng-An Pan, Stephen Wu, Brima Ibrahim
Abstract: An integrated receiver with multiple, independently synchronized clock signals for multiple channel transport stream decoding and delivery substantially implemented on a single CMOS integrated circuit is described. An integrated circuit that services two satellite programs must generate and distribute corresponding time domain clocks to the various components of the integrated circuit. The transport block that receives one or more satellite signals from a demodulating block will extract program clock recover values from each signal being decoded and use these values to produce an error signal or control word that serves as an input to a clock generator. Based upon this input, the clock circuit will produce a corresponding time domain clock for each channel serviced by the integrated circuit. The output of the clock circuit is distributed to the various processing blocks within the integrated circuit that operate upon channel content received and processed by the transport block.
Type:
Grant
Filed:
February 24, 2003
Date of Patent:
June 12, 2007
Assignee:
Broadcom Corporation
Inventors:
Jason Demas, Honman Law, David Baer, Brian Schoner
Abstract: Methods are disclosed for translating or shifting a voltage level of a single ended input. More specifically, the present invention provides a method of translating or shifting a voltage level that doesn't require a complementary input or an additional power supply if the complementary signal isn't available. One embodiment of the method of translating a voltage level of a single-ended input signal using at least one native transistor device having a threshold voltage less than 0V comprises outputting a first voltage level if the single ended input signal is in a first state. A second voltage level is output if the single ended input is in a second state.
Abstract: A system and method for compensating for DC offset and/or clock drift on a wireless-enabled device is described. One embodiment includes a radio module, an A/D converter connected to the radio module, a DC tracking loop connected to the A/D converter, and a multi-hypothesis bit synchronizer.
Abstract: A method and apparatus are disclosed for performing dynamic arbitration of memory accesses by a CPU and at least one bus master interface module based on, at least in part, monitoring a CPU throttle control signal and monitoring CPU power and performance states, and making decisions based on the monitored parameters. Bus master memory access break events and memory read and write accesses are also monitored as part of the arbitration process in accordance with certain embodiments of the present invention. An arbitration (ARB) module performs the dynamic arbitration. A CPU throttle control module generates the CPU throttle control signal, indicating when the CPU is idle, and also monitors and outputs the CPU power and performance states. A memory controller (MC) module controls accesses to the memory subsystem based on, at least in part, the dynamic arbitration performed by the dynamic arbitration module.