Patents Assigned to Broadcom
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Patent number: 6948035Abstract: A node comprises an interconnect, circuitry coupled to the interconnect and configured to initiate a transaction on the interconnect, and a control circuit coupled to provide a response to the transaction on the interconnect. The transaction addresses a block, and the response is indicative of a state of the block in one or more other nodes. The control circuit is configured to cause the transaction to become globally visible to the one or more other nodes dependent on the state in the one or more nodes. Using one or more communication lines separate from lines used to initiate transactions, the control circuit is configured to transmit an indication of the transaction on the interconnect responsive to the transaction becoming globally visible. A transfer of data on the interconnect for the transaction is delayed, responsive to the response from the control circuit, until the indication is transmitted by the control circuit.Type: GrantFiled: April 15, 2003Date of Patent: September 20, 2005Assignee: Broadcom CorporationInventors: Joseph B. Rowlands, Koray Oner
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Patent number: 6946896Abstract: A high temperature coefficient includes a temperature dependent bias generation circuit serially coupled with a variable resistance. The resistance of the variable resistance device increases with increasing temperature such that the output current of the high temperature coefficient circuit is proportional to the resistance of the variable resistance device.Type: GrantFiled: May 29, 2003Date of Patent: September 20, 2005Assignee: Broadcom CorporationInventor: Arya Reza Behzad
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Publication number: 20050200406Abstract: A Variable Gain Amplifier (VGA) amplifies an input signal according to a gain, to produce an amplified signal. A detector module detects a power indicative of a power of the amplified signal. A comparator module compares the detected power to a high threshold, a low threshold and a target threshold intermediate the high and low thresholds. A controller module changes the gain of the VGA so as to drive the detected power in a direction toward the middle threshold when the comparator module indicates the detected power is not between the high and low thresholds.Type: ApplicationFiled: May 2, 2005Publication date: September 15, 2005Applicant: Broadcom CorporationInventors: Leonard Dauphinee, Lawrence Burns
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Patent number: 6943622Abstract: An input buffer amplifier has a symmetrical centroidal layout. The input buffer amplifier includes two half differential amplifiers that have substantially identical layouts. Each half amplifier receives the input signal in-parallel, and the outputs of the differential half amplifiers are wire-ored together. The input buffer amplifier is symmetrical about both horizontal and vertical lines of symmetry. Furthermore, FET devices forming the half amplifiers are interlaced to create the horizontal line of symmetry. The overall horizontal and vertical symmetry of the input buffer amplifier improves the device matching between differential signal paths. In other words, the devices in the half amplifiers that process the positive and negative components of the differential signal are more closely matched. This reduces differential offsets and common mode offsets that can occur when devices are not matched properly.Type: GrantFiled: December 15, 2004Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventor: Sumant Ranganathan
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Patent number: 6943718Abstract: A system (e.g., a digital-to-analog converter (DAC)) includes a digital section and an analog section. The digital section has drivers that generate drive signals based on received digital input signals. The drive signals are received at switches in the analog section of the DAC. The switches generate analog signals therefrom. Swing values of the drive signals are limited to a predetermined amount to substantially eliminate glitch in the analog signals. The drivers can be coupled between first and second nodes that receive different power signal values. Controlling the power signal values allows for the limiting of the swing values. Limiting the swing values limits stored charged in the first and second switches, which substantially eliminates glitch in the analog signals. This can be done regardless on environmental variances (e.g., temperature variance) during operation of the DAC.Type: GrantFiled: August 30, 2004Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventor: Hongwei Wang
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Patent number: 6943587Abstract: An integrated circuit includes a core circuit and a buffer circuit. The buffer circuit includes a plurality of input buffers and a plurality of output buffers that service a plurality of voltage domains on a single set of input/output lines. These voltage domains are controllable to service multiple voltage levels, consistent with various interface standards. In one construction, the core circuit operates at 1.2 volts and the buffer circuit supports both a 1.2 volts interface standard and a 3.3 volts interface standard.Type: GrantFiled: May 30, 2003Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventors: Sridevi R. Joshi, Guangming Yin, Mohammad Nejad, Daniel Schoch
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Patent number: 6944250Abstract: 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: GrantFiled: August 22, 2003Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventors: Henry Samueli, Joseph L. Laskowski
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Patent number: 6944746Abstract: A system and method for processing instructions in a computer system comprising a processor and a co-processor communicatively coupled to the processor. Instructions are processed in the processor in an instruction pipeline. In the instruction pipeline, instructions are processed sequentially by an instruction fetch stage, an instruction decode stage, an instruction execute stage, a memory access stage and a result write-back stage. If a co-processor instruction is received by the processor, the co-processor instruction is held in the core processor until the co-processor instruction reaches the memory access stage, at which time the co-processor instruction is transmitted to the co-processor.Type: GrantFiled: April 1, 2002Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventor: Kimming So
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Patent number: 6944719Abstract: A packetized I/O link such as the HyperTransport protocol is adapted to transport memory coherency transactions over the link to support cache coherency in distributed shared memory systems. The I/O link protocol is adapted to include additional virtual channels that can carry command packets for coherency transactions over the link in a format that is acceptable to the I/O protocol. The coherency transactions support cache coherency between processing nodes interconnected by the link. Each processing node may include processing resources that themselves share memory, such as symmetrical multiprocessor configuration. In this case, coherency will have to be maintained both at the intranode level as well as the internode level. A remote line directory is maintained by each processing node so that it can track the state and location of all of the lines from its local memory that have been provided to other remote nodes.Type: GrantFiled: January 31, 2003Date of Patent: September 13, 2005Assignee: Broadcom Corp.Inventors: Joseph B. Rowlands, Manu Gulati
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Patent number: 6944237Abstract: A method and a system for decoding information signals encoded by a multi-state encoding architecture and transmitted over a multi-dimensional transmission channel by computing a distance of a received word from a codeword. One-dimensional (1D) input signals are detected in a symbol decoder, implemented using look-up tables, to produce a pair of 1D errors, with each representing a distance metric between the input signal and a symbol in one of two disjoint symbol-subsets. The symbol decoder is implemented as a pair of slicers, each detecting an input signal with respect to one of two disjoint symbol-subsets. A third slicer detects the input with respect to the union of the two disjoint symbol-subsets. Decisions from the first, second and third slicers are processed to define 1D square error terms expressed in Hamming metrics. Reduced bit count error terms allow follow-on error processing to be performed with a minimum of computational complexity.Type: GrantFiled: April 16, 2002Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventors: Oscar E. Agazzi, David Kruse, Arthur Abnous, Mehdi Hatamian
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Patent number: 6943596Abstract: Systems and methods are disclosed for a power-on reset used in low power supply voltage applications (i.e., having a full operating power supply voltage of less than about 2.0 volts). One embodiment of the reset circuit comprises a differential voltage generation circuit and an amplifier circuit. The differential voltage generation circuit is adapted to create two voltages changing at different rates. The amplifier circuit is adapted to amplify a difference between the two voltages.Type: GrantFiled: March 12, 2002Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventors: Mark N. Slamowitz, Bassem Radieddine
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Patent number: 6944249Abstract: In one aspect the present invention describes an electronic circuit for transmitting voice packet data over a wireless network with an upstream transmission mode and a downstream transmission mode. The circuit comprises a first phase-lock loop (PLL) for locking a first clock to a time stamp signal, wherein the first clock synchronizes upstream data transmission over the wireless network; and a second PLL for locking a second clock to the time stamp signal, wherein the second clock is used for sampling voice data for downstream voice data transmission over the wireless network.Type: GrantFiled: May 7, 2001Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventors: David Hartman, Mark Dale
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Patent number: 6943589Abstract: A combination multiplexer and tristate circuit. A multiplexer circuit may be configured to receive at least a first data input and a second data input, which are selected by at least a first select signal and a second select signal, respectively. A first circuit is configured to provide an output to an output node responsive to the data input that is selected by the corresponding select signal being active. The multiplexer circuit may further use a tristate circuit, which is also coupled to receive the first select signal and the second select signal. If neither the first select signal nor the second select signal are active, then the tristate circuit is configured to prevent the first circuit from providing an output to the output node.Type: GrantFiled: May 15, 2001Date of Patent: September 13, 2005Assignee: Broadcom CorporationInventor: Daniel W. Dobberphul
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Patent number: 6944435Abstract: An unconditionally stable on-chip filter includes a filtering section and at least one negative resistance module. The filtering section is operably coupled to filter a signal and includes realizable integrated circuit passive components. The at least one negative resistance module is operably coupled to compensate for integrated circuit losses of the filtering section. The realizable integrated circuit passive components have values that are robust, in comparison to parasitic values, have minimal integrated circuit real estate, and provide realizable values for various integrated circuit manufacturing processes including CMOS technology.Type: GrantFiled: June 3, 2002Date of Patent: September 13, 2005Assignee: Broadcom, Corp.Inventors: Harry Contopanagos, Chryssoula Kyriazidou, Jacob Rael, Ahmadreza Rofougaran
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Publication number: 20050195032Abstract: A design for a differential amplifier with a large input common mode signal range. The differential amplifier comprises two differential pairs, each having two amplifying MOSFETs. A source follower is connected to the gate terminal of each amplifying MOSFET in one of the differential pairs. A differential signal applied to the differential amplifier comprises two separate signal. Each separate signal is applied to the gate terminals of both the amplifying MOSFET in the differential pair not driven by the source follower and the driven MOSFET of the source follower. The differential amplifier further comprises a pair of switch MOSFETs connected to a current source MOSFET. The switch MOSFETs act to control the distribution of the total current flowing from the current source MOSFET and, consequently, to determine which differential pair works dominantly to amplify the input signals.Type: ApplicationFiled: April 29, 2005Publication date: September 8, 2005Applicant: Broadcom CorporationInventors: Hongwei Wang, Ardie Venes
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Publication number: 20050198094Abstract: The present invention relates to an adder-subtracter circuit being adapted to process two binary input numbers in order to generate the sum or the difference of the two processed numbers depending on the state of a subtract input signal. Furthermore the circuit has the capability to feed back the result of the processing to itself in order to process one input number together with the result of a previous processing instead of the second binary number.Type: ApplicationFiled: March 5, 2004Publication date: September 8, 2005Applicant: Broadcom CorporationInventor: Andrew Wallace
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Publication number: 20050198478Abstract: 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 for carrying out the operation for each lane.Type: ApplicationFiled: May 6, 2005Publication date: September 8, 2005Applicant: Broadcom CorporationInventor: Sophie Wilson
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Publication number: 20050195335Abstract: A front end circuit for a television receiver includes a demultiplexer for inputting a multi-band signal from a signal source and separating the multi-band signal into corresponding bands. A plurality of amplifiers adjust gain on signals corresponding to the bands. A multiplexer combines outputs of the amplifiers into a gain-adjusted signal. A plurality of switches direct selected bands to corresponding tuners. The amplifiers are low noise amplifiers. The amplifiers adjust gain between the bands so as to have similar signal strength in the bands. A cable TV input may also be used, wherein the switches also direct signals from the cable TV to the corresponding tuners. Each amplifier can output two (or more) identical signals for its corresponding band, the multiplexer can be a dual multiplexer, and an output of the multiplexer includes only bands selected for direction to the tuners.Type: ApplicationFiled: July 2, 2004Publication date: September 8, 2005Applicant: Broadcom CorporationInventors: Ramon Gomez, Charles Brooks, Leonard Dauhinee
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Patent number: 6940293Abstract: A method is contemplated. According to the method, capacitances in a first resistance/capacitance (RC) extraction corresponding to a circuit are modified. Each capacitance is modified to estimate Miller effect on that capacitance. A ratio of a total capacitance on a first wire after the modification in the first RC extraction to a total capacitance on the first wire before the modification in the first RC extraction is calculated. Capacitances in a second RC extraction that are coupled to the first wire are modified according to the ratio. The second RC extraction is a reduced extraction as compared to the first RC extraction. A timing analysis is performed for the circuit using the second RC extraction with capacitances modified to estimate Miller effect.Type: GrantFiled: August 18, 2004Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventors: Kumarswamy Ramarao, Matthew J. Page
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Patent number: 6941440Abstract: A node comprises at least one agent and an input/output (I/O) circuit coupled to an interconnect within the node. The I/O circuit is configured to communicate on a global interconnect to which one or more other nodes are coupled during use. Addresses transmitted on the interconnect are in a first local address space of the node, and addresses transmitted on the global interconnect are in a global address space. The first local address space includes at least a first region used to address at least a first resource of the node. The node is programmable, during use, to relocate the first region within the first local address space, whereby a same numerical value in the first local address space and a second local address space corresponding to one of the other nodes coupled to the global interconnect refers to the first resource in the node during use.Type: GrantFiled: May 15, 2003Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventors: Laurent R. Moll, James D. Kelly, Manu Gulati, Koray Oner, Joseph B. Rowlands