Patents Represented by Attorney, Agent or Law Firm James J. Murphy
  • Patent number: 6055619
    Abstract: An audio information processing subsystem 200 is disclosed which includes a stream processor 100 for simultaneously processing multiple streams of audio data. Processing subsystem 200 also includes a program memory 202 coupled to stream processor 100 for storing instructions for controlling processing system 200 and a data memory 203/204 also coupled to stream processor 100. Additionally, a direct memory access circuitry 208 is provided for controlling direct memory accesses to a selected one of program memory 202 and data memory 203/204.
    Type: Grant
    Filed: February 7, 1997
    Date of Patent: April 25, 2000
    Assignee: Cirrus Logic, Inc.
    Inventors: Gregory Allen North, Douglas D. Gephardt, James D. Barnette, James D. Austin, Scott Thomas Haban, Thomas Saroshan David, Brian Christopher Kircher
  • Patent number: 6043828
    Abstract: A method and apparatus for handling both proprietary and non-proprietary formatted compact discs in the same video playback system. In one embodiment, the audio and video data signals are in a Moving Pictures Expert Group (MPEG) format. Portions of the novel system operate within a high level format independent software library and portions of the novel system operate within a low level software driver of the playback system that receives disc information from a proprietary or non-proprietary disc present to the playback system to be played. The novel system of the present invention includes a disc format determinator for checking the data contained on a disc to see if it includes proprietary information specific to the playback system. In the present invention the proprietary information may be either VideoCD or CD-I disc format information. If a disc presented to the playback system is formatted for a non-proprietary disc format i.e.
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: March 28, 2000
    Assignee: Cirrus Logic, Inc.
    Inventor: Jeffrey Ort
  • Patent number: 6041389
    Abstract: A memory 200 including an array 202 of addressable memory cells and a content addressable memory cell 207/300 for comparing a received select bit with a stored select bit and enabling access to addressed ones of the memory cells in response.
    Type: Grant
    Filed: November 16, 1995
    Date of Patent: March 21, 2000
    Assignee: E Cirrus Logic, Inc.
    Inventor: G. R. Mohan Rao
  • Patent number: 6025840
    Abstract: A processing system 100 is disclosed which includes a system master 101, a system bus 102 coupled to the master, and a plurality of bus interface circuits 106 coupled to bus 102. A first one of the bus interfaces 106 includes a mapping signal input coupled to the master and a mapping signal output, the first bus interface 106 operable to latch-in at least one first selected address bit presented by the master on the system bus in response to a mapping enable signal received at the mapping signal input from the master 101. A second bus interface 106 is provided coupled to the bus 102 and having a mapping signal input coupled to the mapping signal output of first bus interface 106, the second bus interface 106 operable to latch-in at least one second selected address bit presented by the master 101 on the bus 102 in response to a second mapping enable signal received at the mapping input of the second bus interface 106 from the first bus interface 106.
    Type: Grant
    Filed: September 27, 1995
    Date of Patent: February 15, 2000
    Assignee: Cirrus Logic, Inc.
    Inventor: Ronald T. Taylor
  • Patent number: 6020863
    Abstract: A display control system (200) for transferring video and graphical data processed in a first processing device (201) having a dedicated display screen to a second processing device (202) for display on the screen (152) of a conventional television set (150). The first processing device (201) and the second processing device (202) communicate by means of a pair of optical driver/receivers (203, 207). The second processing device (202) captures selected frames from a broadcast television picture displayed on the screen (152) of the television (150) and transmits the captured frames to the first processing device (201) for storage or display on the dedicated display screen.
    Type: Grant
    Filed: February 27, 1996
    Date of Patent: February 1, 2000
    Assignee: Cirrus Logic, Inc.
    Inventor: Ronald T. Taylor
  • Patent number: 6018793
    Abstract: A memory architecture 104 includes a plurality of arrays 200 of memory cells. Addressing circuitry 201 selects a cell of a selected one of arrays 201 for access while feature select circuitry 205 selects an access type to be performed to the selected cell. A first bus 207, 208, 209 exchanges a bit of data with the selected cell in response to the selection of a first access type. A second bus 207, 208, 209 exchanges a bit of data with the selected cell in response to the selection of a second access type.
    Type: Grant
    Filed: October 24, 1997
    Date of Patent: January 25, 2000
    Assignee: Cirrus Logic, Inc.
    Inventor: G. R. Mohan Rao
  • Patent number: 6012142
    Abstract: A message is transferred from external device through a first processor and from the first processor to a second processor. A check is made that the message passed to the second processor without error. The message is interpreted by a selected one of the first and second processors. Boot operations are performed by the selected processor in response to the interpretation of the message.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: January 4, 2000
    Assignee: Cirrus Logic, Inc.
    Inventors: Miroslav Dokic, Raghunath Rao, Terry Ritchie, James Divine, Jeffrey Niehaus, Zheng Luo
  • Patent number: 6011501
    Abstract: Digital-to-analog conversion circuitry 100 is shown including a path for processing data in a 1-bit format. First portion of an analog finite impulse response filter 300 includes pre-selected number of delay elements 301 for receiving stream of data in the 1-bit format and outputting a plurality of signals in response. A switched capacitor digital-to-analog converter 106 forms a second portion of the finite impulse response filter 301 and has a plurality of elements each receiving one of the plurality of signals as selected to effectuate a set of filter coefficients, converter 106 summing the plurality of signals and outputting an analog data stream.
    Type: Grant
    Filed: December 31, 1998
    Date of Patent: January 4, 2000
    Assignee: Cirrus Logic, Inc.
    Inventors: Xue-Mei Gong, John James Paulos, Mark Alexander, Eric Gaalaas, Dylan Hester
  • Patent number: 6009389
    Abstract: A method of concealing errors received in a stream of data by a multiprocessor system having a first digital signal processor for initial processing of incoming data and a second digital signal processor for processing data passed from the first processor. The method includes the steps of detecting an error in an incoming frame of the stream of data with the first processor, sending an error message from the first to the second processor, halting transmission of the remainder of the frame to the second processor, and processing a frame of dummy data with the second processor. The frame of dummy data is passed to a processing engine forming a portion of the second processor to maintain data pipelining. Interprocessor communications between the first and second processors is established by handshaking through an interprocessor communications register, wherein the first processor detects an error in a frame of data and sends a message to the second processor.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: December 28, 1999
    Assignee: Cirrus Logic, Inc.
    Inventors: Miroslav Dokic, Raghunath Rao
  • Patent number: 5982696
    Abstract: A memory 201 comprising an array 302 of memory cells, an address decoder 303, 305 for accessing a selected one of the cells in response to at least one address bit, and a programmable array 311 for selectively presenting the at least one address bit to the address decoder 303, 305 in response to a control signal.
    Type: Grant
    Filed: June 6, 1996
    Date of Patent: November 9, 1999
    Assignee: Cirrus Logic, Inc.
    Inventor: G. R. Mohan Rao
  • Patent number: 5978825
    Abstract: A method of generating zero detect flag at the output of an adder adding a first vector and a second vector to generate a third vector. A fourth vector is generated from the third vector a carry propagation vector and a carry generation vector. A fifth vector generated using an incremented third vector and an incremented carry propagation vector. A sixth vector generated from the fourth vector and the fifth vector. The bits of the sixth vector bitwise added to obtain the zero detection flag.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: November 2, 1999
    Assignee: Crystal Semiconductor Corp.
    Inventors: James Divine, Jeffrey Niehaus
  • Patent number: 5978293
    Abstract: A sense amplifier sensing data on a pair of complimentary half-bitlines 301a, 301b connected to a static random access memory cell 300. First and second sensing transistors 405a, 405b amplify a voltage difference between first and second half-bitlines 301 during an active cycle. First and second restore transistors 404a, 404b pull the first and second half-bitlines to corresponding first and second voltage rails in response to the amplified voltage difference. SR Latch 406, 407 retains data from cycle to cycle.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: November 2, 1999
    Assignee: Cirrus Logic, Inc.
    Inventor: Ronald T. Taylor
  • Patent number: 5960401
    Abstract: A method of processing exponent data in an audio decoder. A first block of audio data is received including encoded exponent data. The encoded exponent data is packed into packed encoded words and stored in memory. Exponents are generated from the packed encoded words in memory for processing the first block of audio data. A second block of audio data is received. A determination is made as to whether a reuse flag has been set for the second block, and if the reuse flag has been set, exponents are generated from the packed encoded words memory for processing the second block of data.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: September 28, 1999
    Assignee: Crystal Semiconductor Corporation
    Inventors: Raghunath Rao, Miroslav Dokic
  • Patent number: 5950219
    Abstract: A memory 200 comprising a first memory bank 201a including an array 202a of memory cells and a circuitry 203a, 205a for addressing a location within array 202a. Memory 200 further includes a second memory bank 201b including an array 202b of memory cells and circuitry 203b, 205b for addressing location within array 202b. Circuitry 203, 206, 207 is included for selectively pipelining a plurality of serially received words of address bits to the banks 201 during precharge of the banks.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: September 7, 1999
    Assignee: Cirrus Logic, Inc.
    Inventor: G. R. Mohan Rao
  • Patent number: 5945974
    Abstract: A display controller 104 for use with a display device 107 operable to display images on a screen. Display controller 104 includes circuitry 201-210 for presenting first data to the display device 107 for generating an image in a first areas of the screen, the first data being retrieved from an external frame buffer 108. A display controller 104 further includes circuitry 205, 210 for presenting second data to the display device 107 for generating an image in the second area of the screen, the second data being retrieved from an internal frame buffer 206.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: August 31, 1999
    Assignee: Cirrus Logic, Inc.
    Inventors: Sudhir Sharma, G.R. Mohan Rao, Michael E. Runas
  • Patent number: 5926428
    Abstract: A memory includes a bitline comprised of 2 half-bitlines with at least one cell coupled to each of the half-bitlines. A sense amplifier for detecting a voltage difference is coupled between the half-bitlines. A control signal controls the current through the sense amplifier. A method is provided for sensing data by precharging a pair of half-bitlines, activating a storage cell coupled to one half-bitline and reference cell coupled to its complement. A sense amplifier senses the voltage difference between the half-bitlines by initiating current flow through the sense amplifier during an intitial period and increasing the current flow during a subsequent period.
    Type: Grant
    Filed: June 16, 1998
    Date of Patent: July 20, 1999
    Assignee: Cirrus Logic, Inc.
    Inventor: G. R. Mohan Rao
  • Patent number: 5920885
    Abstract: A dynamic random access memory (DRAM) includes priority access control circuitry, where the DRAM has a first precharge mode and a priority precharge mode. In the first precharge mode, the array is precharged during an external row address strobe (RAS) and accessed during an active state of the external RAS. In the priority precharge mode, the array is precharged during a precharge state of an internal RAS initiated by a priority signal received during any one of the precharge and active states of the external RAS, where the priority access control circuitry returns to the first mode on a subsequent precharge state of the external RAS.
    Type: Grant
    Filed: June 1, 1998
    Date of Patent: July 6, 1999
    Assignee: Cirrus Logic, Inc.
    Inventor: G. R. Mohan Rao
  • Patent number: 5914900
    Abstract: A memory system 104 includes an array 200 of memory cells arranged in rows and columns. Circuitry 208 is included for selectively performing logic operations on a bit of data stored in a selected cell using a bit of received modifying data and mode data bit for selecting a logic operation for performance. Circuitry 208 for performing logic operations is operable during an AND logic operation to write data into the cell when the bit of modifying data is a logic zero and maintaining an existing bit stored in the cell when the bit of modifying data is a logic one. Also included is circuitry 207, 210 for receiving and latching the mode data bit and the modifying data through a single port.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: June 22, 1999
    Assignee: Cirrus Logic, Inc.
    Inventors: Sudhir Sharma, Michael E. Runas, Robert M. Nally
  • Patent number: 5912853
    Abstract: An amplifier 300 includes a differential pair of transistors 307a, 307b. A third transistor 306 controls current through transistors 307a, 307b of the differential pair in response to a stepped control signal.
    Type: Grant
    Filed: December 3, 1996
    Date of Patent: June 15, 1999
    Assignee: Cirrus Logic, Inc.
    Inventor: G. R. Mohan Rao
  • Patent number: 5910919
    Abstract: A memory system 104 includes an array 200 of memory calls arranged in rows and columns and circuitry 208 for selectively performing logic operations on a bit of data stored in a selected call using a bit of received modifying data and a mode data bit for selecting a logic operation for performance. Circuitry 208 for modifying during an OR logic operation writing bit of the modifying data into the cell when the bit of modifying data is a logic one and maintaining an existing bit stored in call when the bit of modifying data is a logic zero. Memory system 104 further includes circuitry 207, 210 for receiving and latching the mode data and the modifying data through a single port.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: June 8, 1999
    Assignee: Cirrus Logic, Inc.
    Inventors: Sudhir Sharma, Michael E. Runas, Robert M. Nally