Patents Assigned to Broadcom
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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: 6940434Abstract: Methods and systems for applying digital dither includes methods and systems for applying digital dither in data converters, such as, for example, delta-sigma data converters. In an embodiment, an analog signal from a first path of a delta-sigma modulator is quantized to an m-bit digital signal and an n-bit dithered digital feedback signal is generated from at least a portion of the m-bit digital signal. The n-bit dithered digital feedback signal is converted to an analog feedback signal and fed back to a second path of the delta-sigma modulator. In an embodiment, the n-bit dithered digital feedback signal is generated by selecting one of a plurality of sets of n-bits from the m-bit digital signal depending upon a state of a dither control signal. The dither control signal can alternate between a plurality of states or pseudo-randomly switch between a plurality of states.Type: GrantFiled: June 7, 2004Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventor: Todd Lee Brooks
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Patent number: 6941334Abstract: A floating point unit includes a multiplier, an approximation circuit, and a control circuit coupled to the multiplier and the approximation circuit. The approximation circuit is configured to generate an approximation of a difference of the first result from the multiplier and a constant. The control circuit is configured to approximate a function specified by a floating point instruction provided to the floating point unit for execution using an approximation algorithm. The approximation algorithm comprises at least two iterations through the multiplier and optionally the approximation circuit. The control circuit is configured to correct the approximation from the approximation circuit from a first iteration of the approximation algorithm during a second iteration of the approximation algorithm by supplying a correction vector to the multiplier during the second iteration. The multiplier is configured to incorporate the correction vector into the first result during the second iteration.Type: GrantFiled: February 1, 2002Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventors: Robert Rogenmoser, Michael C. Kim
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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
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Patent number: 6940306Abstract: Methods and circuitry for implementing high speed first-in first-out (FIFO) structures. In one embodiment, a FIFO is disclosed that allows the frequency of one clock, e.g., the write clock, to be different than (e.g., half) that of the other (read) clock. In another embodiment a FIFO is presented that can be set and/or reset asynchronously. Other embodiments are disclosed wherein the read and write pointers are effectively monitored to ensure proper timing relationship, to detect loss of clock as well as to detect other abnormal FIFO conditions.Type: GrantFiled: December 31, 2003Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventors: Afshin Momtaz, Xin Wang, Jun Cao, Armond Hairapetian, David Chung
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Patent number: 6940929Abstract: A method for decoding a word received at a current time instant into a symbol of a trellis code. The trellis code corresponds to a trellis diagram having N states associated with the current time instant. Each of the N states corresponds to at least one incoming branch. Each of the incoming branches is associated with a symbol of the trellis code. The branch metrics are computed for the incoming branches such that a branch metric represents a distance between the received word and a symbol associated with the corresponding branch. The branch metric is represented by fewer bits than a squared Euclidian metric representation of the distance. For each of the N states, a node metric is computed based on corresponding branch metrics and one of the incoming branches associated with the state is selected. One of the N states is selected as an optimal state based on the node metrics. The symbol associated with the selected incoming branch corresponding to the optimal state is the decoded word.Type: GrantFiled: April 21, 2004Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventor: Kelly B. Cameron
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Patent number: 6940928Abstract: Method and apparatus for Soft In Soft Out Turbo Code Decoder. Metrics are received by a decoder having SISO unit(s). The SISO unit computes all the alpha values corresponding to a block of data. Of the alpha values computed some alpha values, for example alpha values selected at regular intervals, corresponding to checkpoint values are pushed on a checkpoint stack. Alpha values are computed with some being saved as checkpoint values and some being discarded are computed until the computation reaches a predetermined distance from the end of the block of data. Once the predetermined distance is reached all alpha values are pushed on a computation stack. Once all the values corresponding to the values between the predetermined end of the block and the end of the block have been computed and placed in the computation stack they may be combined with beta values to produce extrinsic values.Type: GrantFiled: September 12, 2001Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventor: Kelly B. Cameron
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Patent number: 6940560Abstract: A method and system for performing combing for PAL luma data is disclosed. The combing is performed for a display having a plurality of lines. The display is capable of depicting a frame including a horizontal boundary having a top edge and a bottom edge. A top line of the plurality of lines is at the top edge of the horizontal boundary. A bottom line of the plurality of lines is at the bottom edge of the horizontal boundary. The method and system includes providing a feedback multiplexer, a line delay and a feed forward multiplexer. The feedback multiplexer has a first input, a second input and a first output. The first input is for receiving luma data for a current line. The line delay has a delay input and a delay output, the delay input coupled with the first output. The delay output is coupled with the second input. The feed forward multiplexer has a third input, a fourth input and a second output. The third input is coupled with the delay output.Type: GrantFiled: June 29, 2004Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventors: Aleksandr M. Movshovich, Brad A. Delanghe
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Patent number: 6941406Abstract: An apparatus includes one or more interface circuits, an interconnect, a memory controller, a memory bridge, a packet DMA circuit, and a switch. The memory controller, the memory bridge, and the packet DMA circuit are coupled to the interconnect. Each interface circuit is coupled to a respective interface to receive packets and/or coherency commands from the interface. The switch is coupled to the interface circuits, the memory bridge, and the packet DMA circuit. The switch is configured to route the coherency commands from the interface circuits to the memory bridge and the packets from the interface circuits to the packet DMA circuit. The memory bridge is configured to initiate corresponding transactions on the interconnect in response to at least some of the coherency commands. The packet DMA circuit is configured to transmit write transactions on the interconnect to the memory controller to store the packets in memory.Type: GrantFiled: June 4, 2004Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventors: Barton J. Sano, Joseph B. Rowlands, James B. Keller, Laurent R. Moll, Koray Oner, Manu Gulati
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Patent number: 6940766Abstract: A method for locating a repair solution for a memory that includes a memory array comprising a plurality of rows and a plurality of columns, N redundant rows, and M redundant columns is described. Both N and M are integers, where N is greater than or equal to zero and M is greater than or equal to zero. The N redundant rows and the M redundant columns are collectively referred to as redundant lines. The method includes generating a first defect matrix representing defects in the memory array. Additionally, the method includes recursively, until either the repair solution is found or the redundant lines are consumed: selecting a first line represented in the defect matrix and having at least one defect; generating a second defect matrix by eliminating at least the defects in the first line from the first defect matrix; and determining if the repair solution is found.Type: GrantFiled: July 2, 2004Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventors: Haluk Konuk, José L. Landivar, Zongbo Chen
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Patent number: 6940904Abstract: A method and apparatus for decoding and displaying a progressive refresh bitstream, such as, for example, Motorola/GI HITS bitstream, is provided. The method avoids displaying artifacts caused by displaying incompletely decoded pictures after channel acquisition. After the channel acquisition, an entry picture, a P-picture with the refreshed I-slices at the top of the picture, is first displayed with all pixels below the refreshed I-slices zeroed (blacked) out. Then the subsequent P-pictures are displayed with all pixels below their respective refreshed I-slices zeroed out. Once a P-picture has been completely decoded, normal decoding process is started.Type: GrantFiled: May 29, 2001Date of Patent: September 6, 2005Assignee: Broadcom CorporationInventors: Xuemin Chen, Jason Demas
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Publication number: 20050190690Abstract: A multi-port Serdes transceiver includes multiple parallel ports and serial ports, and includes the flexibility to connect any of the parallel ports to another parallel port or to a serial port, or both. Furthermore, the transceiver can connect any of the serial ports to another serial port or to a parallel port. The transceiver further includes a switch, a logic core, and a bus. The switch is selectively coupled to at least a first port and a second port. The switch activates the first port and deactivates the second port based on satisfaction of a condition associated with the first port. The logic core operates the serial and parallel ports, and the bus connects the ports. The bus can be described as a “ring” structure (or donut “structure”) around the logic core, and is configured between the logic core and the ports. The ring structure provides efficient communication between the logic core and the ports.Type: ApplicationFiled: April 29, 2005Publication date: September 1, 2005Applicant: Broadcom CorporationInventor: Hoang Tran
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Publication number: 20050193303Abstract: An improved automated testing system that decreases the number of test signals that must be stored in the tester pattern memory for a timed test pattern. In the present invention, a timed test pattern is controlled by a timing generator operable to change the timing interval of individual test cycles during the timed test pattern between first and second timing intervals, thereby decreasing the number of test signals stored in pattern memory for the timed test pattern. The method and apparatus of the present invention can be implemented to test integrated circuits comprising circuitry operating in first and second time domains wherein the first and second timing intervals of the timed test pattern correspond to the first and second time domains of the circuit, respectively.Type: ApplicationFiled: February 13, 2004Publication date: September 1, 2005Applicant: Broadcom CorporationInventor: Haluk Konuk
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Publication number: 20050191984Abstract: A receiver portion includes a bandpass filter (e.g. SAW filter) that performs channel selection from an input signal having a plurality of channels, and an image cancellation circuit that is in parallel with the bandpass filter. The bandpass filter performs channel selection to select a desired channel that falls in a passband of the bandpass filter. Since the passband is typically a few channels wide, the image channel falls outside the passband and is attenuated by the stopband attenuation of the bandpass filter. The image cancellation circuit includes an attenuator and a phase shifter. The attenuator is configured to have the same attenuation as the stopband attenuation of the bandpass filter at the image channel frequency, and phase shifter is configured to provide a phase shift of approximately 180 degrees. Therefore, the image cancellation circuit has an output that is equal in amplitude, but opposite in phase, to that of the bandpass filter at the image channel frequency.Type: ApplicationFiled: March 31, 2004Publication date: September 1, 2005Applicant: Broadcom CorporationInventors: Leonard Dauphinee, Lawrence Burns
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Publication number: 20050189973Abstract: A charge pump circuit includes a charge pump having an output voltage. A replica circuit actively matches up and down currents in the charge pump. A charge pump bias current transistor biases the charge pump. The charge pump includes four switches driven by differential UP and DOWN signals. The charge pump includes a first tail current source connected between a supply voltage and two of the four switches that are driven by the differential UP signal, and a second tail current source connected between a supply voltage and two of the four switches that are driven by the differential DOWN signal. The charge pump includes an operational amplifier whose output is connected to an output of one of the tail current sources. A dump capacitor is connected to a negative input of the operational amplifier. The replica circuit includes four transistors, two of which match the first and second tail current sources, and the other two match the switches driven by the differential UP and DOWN signals.Type: ApplicationFiled: February 27, 2004Publication date: September 1, 2005Applicant: Broadcom CorporationInventor: Ning Li
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Publication number: 20050190696Abstract: Upstream requests such a bandwidth requests, are processed by CMTS out of order on a priority basis to reduce latency in responding to the request. Specifically, a cable modem termination system (CMTS) is connected to a plurality of cable modems by a cable plant. The CMTS has a burst receiver adapted to be connected to the cable plant to process upstream data packet units and bandwidth requests transmitted by the cable modems. Each packet includes a header that uniquely distinguishes the bandwidth requests from other data types. Packet data units are arranged in a first memory queue. Bandwidth requests are arranged in a second memory queue. The headers of the packets processed by the burst receiver are inspected as they arrive at the CMTS to determine if the packets are packet data units or bandwidth requests. Packet data units are routed to the first memory queue. Bandwidth requests are routed to the second memory queue.Type: ApplicationFiled: May 4, 2005Publication date: September 1, 2005Applicant: Broadcom CorporationInventors: Lisa Denney, Anders Hebsgaard, Robert Lee
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Publication number: 20050189982Abstract: A charge pump includes a resistor divider connected between an output voltage node and ground and a comparator inputting a reference voltage at one input, and a divided voltage from the resistor divider at another input. A digital control circuit is enabled by the comparator. A first transistor and a second transistor are in series between an input voltage node and the ground, both transistors controlled by the digital control circuit. A pump capacitor is connected between to the output voltage node and between the first and second transistor, and being charged by turning the first and second transistors on and off. A first diode is between the pump capacitor and the input voltage node. A second diode between the pump capacitor and the output voltage node. A reservoir capacitor between the output voltage node and ground. The digital control circuit comprises a first shift register.Type: ApplicationFiled: February 27, 2004Publication date: September 1, 2005Applicant: Broadcom CorporationInventors: Yee Cheung, Chun-Ying Chen
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Publication number: 20050190845Abstract: A method and apparatus for decoding and displaying a bitstream, such as, for example, Motorola/GI HITS bitstream, is provided. The method avoids displaying artifacts caused by displaying incompletely decoded pictures after channel acquisition. After the channel acquisition, an entry picture, a P-picture with the refreshed I-slices at the top of the picture, is first displayed with all pixels below the refreshed I-slices zeroed (blacked) out. Then the subsequent P-pictures are displayed with all pixels below their respective refreshed I-slices zeroed out. Once a P-picture has been completely decoded, normal decoding process is started.Type: ApplicationFiled: April 25, 2005Publication date: September 1, 2005Applicant: Broadcom CorporationInventors: Xuemin Chen, Jason Demas
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Publication number: 20050193185Abstract: Methods and systems for executing SIMD instructions that efficiently implement new SIMD instructions and conventional existing SIMD MAC-type instructions, while avoiding replication of functions in order to keep the size of the logic circuit size to as low a level as can reasonably be achieved. An instruction unit executes Single Instruction Multiple Data instructions, including instructions acting on operands representing complex numbers. The instruction unit includes functional blocks that are commonly utilized to execute a plurality of the instructions, wherein the plurality of instructions utilize various individual functional blocks in various combinations with one another. The plurality of instructions is optionally executed in a pipeline fashion.Type: ApplicationFiled: October 4, 2004Publication date: September 1, 2005Applicant: Broadcom CorporationInventors: Mark Taunton, Andrew Dawson
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Publication number: 20050190516Abstract: A circuit for protection of a transceiver input includes an input transistor and a first resistor connected between the drain of the input transistor and an input node. A plurality of reverse-biased diodes connected between a supply voltage and the input node. An output node is connected to the source of the input transistor. A first forward-biased diode connected between the power supply and the plurality of reverse-biased transistors. A second forward-biased diode and a second resistor are connected between the first forward biased transistor and the gate of the input transistor. A pre-driver circuit includes first and second transistors forming a differential pair and driven by a differential input voltage. A third transistor is connected between sources of the first and second transistors and ground. First and second resistors are connected to drains of the first and second transistors, respectively. A fourth transistor is connected between a power supply voltage and the first and second resistors.Type: ApplicationFiled: February 27, 2004Publication date: September 1, 2005Applicant: Broadcom CorporationInventors: Wee Lee, Tu Yun, Tian Teo