Division Patents (Class 708/650)
  • Publication number: 20130124594
    Abstract: An integrated circuit comprises divider circuitry configured to perform a division operation. The divider circuitry may be part of an arithmetic logic unit or other computational unit of a microprocessor, digital signal processor, or other type of processor. The divider circuitry iteratively determines bits of a quotient over multiple stages of computation. In determining the quotient in one embodiment, the divider circuitry is configured to estimate a partial remainder for a given one of the stages and to predict one or more of the quotient bits for one or more subsequent stages based on the estimated partial remainder so as to allow one or more computations to be skipped for said one or more subsequent stages, thereby reducing power consumption. The integrated circuit may be incorporated in a computer, a mobile telephone, a storage device or other type of processing device.
    Type: Application
    Filed: November 15, 2011
    Publication date: May 16, 2013
    Applicant: LSI Corporation
    Inventors: Prakash Krishnamoorthy, Ramesh C. Tekumalla
  • Patent number: 8443023
    Abstract: A system and method are provided for synthesizing signal frequencies using rational division. The method accepts a reference frequency value and a synthesized frequency value. In response to dividing the synthesized frequency value by the reference frequency value, an integer value numerator (dp) and an integer value denominator (dq) are determined. The method reduces the ratio of dp/dq to an integer N and a ratio of p/q (dp/dq=N(p/q)), where p/q<1 (decimal). The numerator (p) and the denominator (q) are supplied to a flexible accumulator module, and a divisor is generated as a result. N is summed with a k-bit quotient to create the divisor. In a phase-locked loop (PLL), the divisor and the reference signal are used to generate a synthesized signal having a frequency equal to the synthesized frequency value.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: May 14, 2013
    Assignee: Applied Micro Circuits Corporation
    Inventors: Viet Linh Do, Simon Pang, Hongming An, Jim Lew
  • Publication number: 20130103733
    Abstract: A method and apparatus are provided for manufacturing integrated circuits performing invariant integer division x/d. A desired rounding mode is provided and an integer triple (a,b,k) for this rounding mode is derived. Furthermore, a set of conditions for the rounding mode is derived. An RTL representation is then derived using the integer triple. From this a hardware layout can be derived and an integrated circuit manufactured with the derived hardware layout. When the integer triple is derived a minimum value of k for the desired rounding mode and set of conditions is also derived.
    Type: Application
    Filed: September 26, 2012
    Publication date: April 25, 2013
    Applicant: IMAGINATION TECHNOLOGIES LIMITED
    Inventor: Imagination Technologies Limited
  • Patent number: 8402078
    Abstract: A method, computer program product and a system for controlling a fixed point division operation are provided. The method includes: receiving an instruction to perform a division operation for a dividend and a divisor, the operation comprising a maximum number of iterations to produce a quotient having a maximum precision; calculating a magnitude of at least one of the dividend and the divisor; determining a quotient precision based on the magnitude; and computing a required number of iterations needed to produce the quotient precision and performing the number of iterations.
    Type: Grant
    Filed: February 26, 2008
    Date of Patent: March 19, 2013
    Assignee: International Business Machines Corporation
    Inventors: Joshua M. Weinberg, Martin S. Schmookler
  • Patent number: 8392494
    Abstract: A time-invariant method and apparatus for performing modular reduction that is protected against cache-based and branch-based attacks is provided. The modular reduction technique adds no performance penalty and is side-channel resistant. The side-channel resistance is provided through the use of lazy evaluation of carry bits, elimination of data-dependent branches and use of even cache accesses for all memory references.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: March 5, 2013
    Assignee: Intel Corporation
    Inventors: Vinodh Gopal, Gilbert M. Wolrich, Wajdi K. Feghali, James D. Guilford, Erdinc Ozturk, Martin G. Dixon
  • Patent number: 8346840
    Abstract: A system and method are provided for rational division. The method accepts accepting a binary numerator and a binary denominator. A binary first sum is created of the numerator and a binary first count from a previous cycle. A binary first difference is created between the first sum and the denominator. In response to comparing the first sum with the denominator, and first carry bit is generated and added to a first binary sequence. The first binary sequence is used to generate a k-bit quotient. Typically, the denominator value is larger than the numerator value. In one aspect, the numerator and denominator form a rational number. Alternately, the numerator may be an n-bit bit value formed as either a repeating or non-repeating sequence, and the denominator is an (n+1)-bit number with a decimal value of 2(n+1).
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: January 1, 2013
    Assignee: Applied Micro Circuits Corporation
    Inventors: Viet Linh Do, Simon Pang
  • Publication number: 20120259907
    Abstract: A pipelined circuit for performing a divide operation on small operand sizes. The circuit includes a plurality of stages connected together in a series to perform a subtractive divide algorithm based on iterative subtractions and shifts. Each stage computes two quotient bits and outputs a partial remainder value to the next stage in the series. The first and last stages utilize a radix-4 serial architecture with edge modifications to increase efficiency. The intermediate stages utilize a radix-4 parallel architecture. The divide architecture is pipelined such that input operands can be applied to the divider on each clock cycle.
    Type: Application
    Filed: April 7, 2011
    Publication date: October 11, 2012
    Inventors: Christopher H. Olson, Jeffrey S. Brooks
  • Publication number: 20120254276
    Abstract: A complex divider utilized for dividing a first complex number by a second complex number to generate a computing result includes a computing unit and a dividing unit. The computing unit is utilized for receiving the first complex value and the second complex value, generating a third complex value according to the first complex value and the second complex value, and generating a real number according to the second complex value. The dividing unit is coupled to the computing unit, and is utilized for receiving the third complex value and the real number and dividing the third complex value by the real number to obtain the computing result.
    Type: Application
    Filed: March 27, 2012
    Publication date: October 4, 2012
    Inventor: Yi-Lin Li
  • Patent number: 8261176
    Abstract: Systems and methods to perform polynomial division are disclosed. In a particular embodiment, the method includes receiving a codeword and storing a portion of the received codeword at a register. The portion of the received codeword has a first number of terms. A divisor having a second number of terms is also received. During at least one stage of a multi-stage polynomial division operation using the portion of the codeword and the divisor, the portion of the received codeword to be divided by the divisor is adjusted based on a result of a comparison of the first number to the second number.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: September 4, 2012
    Assignee: Sandisk IL Ltd.
    Inventors: Idan Alrod, Eran Sharon
  • Patent number: 8255447
    Abstract: The present invention provides an eigenvalue decomposition apparatus that can perform processing in parallel at high speed and high accuracy.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: August 28, 2012
    Assignee: Kyoto University
    Inventors: Yoshimasa Nakamura, Hiroaki Tsuboi, Taro Konda, Masashi Iwasaki, Masami Takata
  • Patent number: 8233614
    Abstract: The invention relates to a cryptographic method involving an integer division of type q=a div b and r=a mod b, wherein a is a number of m bits, b is a number of n bits, with n being less than or equal to m, and bn?1 being non-null and the most significant bit of b. In addition, each iteration of a loop subscripted by i, which varies between 1 and m?n+1, involves a partial division of a word A of n bits of number a by number b in order to obtain one bit of quotient q. According to the invention, the same operations are performed with each iteration, regardless of the value of the quotient bit obtained. In different embodiments of the invention, one of the following is also performed with each iteration: the addition and subtraction of number b to/from word A; the addition of number b or a complementary number /b of b to word A; or a complement operation at 2n of an updated datum (b or /b) or a dummy datum (c or /c) followed by the addition of the datum updated with word A.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: July 31, 2012
    Assignee: Gemalto SA
    Inventors: Marc Joye, Karine Villegas
  • Patent number: 8229109
    Abstract: Techniques are described to determine N mod M, where N is a number having a width of n-bits, and M is a number having a width of m-bits. The techniques, generally, involve determining N?=Nrt2f mod M+NL and, subsequently, determining N? mod M.
    Type: Grant
    Filed: June 27, 2006
    Date of Patent: July 24, 2012
    Assignee: Intel Corporation
    Inventors: William C. Hasenplaugh, Gunnar Gaubatz, Vinodh Gopal
  • Publication number: 20120166512
    Abstract: Techniques for efficiently performing division and modulo operations in a programmable logic device. In one set of embodiments, the division and modulo operations are synthesized as one or more alternative arithmetic operations, such as multiplication and/or subtraction operations. The alternative arithmetic operations are then implemented using dedicated digital signal processing (DSP) resources, rather than non-dedicated logic resources, resident on a programmable logic device. In one embodiment, the programmable logic device is a field-programmable gate array (FPGA), and the dedicated DSP resources are pre-fabricated on the FPGA. Embodiments of the present invention may be used in Ethernet-based network devices to support the high-speed packet processing necessary for 100G Ethernet, 32-port (or greater) trunking, 32-port/path (or greater) load balancing (such as 32-path ECMP), and the like.
    Type: Application
    Filed: February 11, 2008
    Publication date: June 28, 2012
    Applicant: Foundry Networks, Inc.
    Inventors: Yuen Wong, Hui Zhang
  • Publication number: 20120131082
    Abstract: Methods, computer systems, and computer program products for calculating a remainder by division of a sequence of bytes interpreted as a first number by a second number is provided. A pseudo-remainder by division associated with a first subsequence of the sequence of bytes is calculated. A property of this pseudo-remainder is that the first subsequence of the sequence of bytes, interpreted as a third number, and the pseudo-remainder by division have the same remainder by division when divided by the second number. A second subsequence of the sequence of bytes interpreted as the first number is appended to the pseudo-remainder, interpreted as a sequence of bytes, so as to create a sequence of bytes interpreted as a fourth number. The first number and the fourth number have the same remainder by division when divided by the second number.
    Type: Application
    Filed: November 23, 2010
    Publication date: May 24, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Michael HIRSCH, Shmuel T. KLEIN, Yair TOAFF
  • Patent number: 8170695
    Abstract: Methods and a system are disclosed for one or more appliances including a controller for managing power consumption within a household. The controller is configured to receive and process a signal indicative of one or more energy parameters of an associated energy utility, including at least a peak demand period or an off-peak demand period. A generated serial number is obtained from an original serial number of the appliance or controller, which is configured for a signal to communicate to the appliance within a population and command the appliance to operate in an energy savings mode and a normal mode at various time periods. The generated serial number (GSN) is used to segregate a total population into segments to provide granularity in assigning DR activations and deactivations based upon the GSN.
    Type: Grant
    Filed: July 16, 2010
    Date of Patent: May 1, 2012
    Assignee: General Electric Company
    Inventors: Lucas Bryant Spicer, John K. Besore
  • Patent number: 8139696
    Abstract: A method is provided of characterising a data stream of binary symbols, the method comprising sampling the stream at a predetermined rate sufficient to capture at least two samples per binary symbol, identifying the shortest continuous run of samples having the same logic level and assigning a symbol rate to the stream on the basis that the identified run is one symbol in length.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: March 20, 2012
    Assignees: MStar Semiconductor, Inc., MStar Software R&D, Ltd., MStar France SAS, MStar Semiconductor, Inc.
    Inventor: Richard Neil Hunt
  • Patent number: 8140608
    Abstract: One embodiment of the present invention sets forth a technique for performing fast integer division using commonly available arithmetic operations. The technique may be implemented in a two-stage process using a single-precision floating point reciprocal in conjunction with integer addition and multiplication. Furthermore, the technique may be fully pipelined on many conventional processors for performance that is comparable to the best available high-performance alternatives.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: March 20, 2012
    Assignee: NVIDIA Corporation
    Inventor: Norbert Juffa
  • Publication number: 20120066283
    Abstract: Provided are a divider having a small area and an improved operation speed and a method of operating the same. The divider includes a memory, a controller, and a multiplier. The memory is configured to store table values included in a predetermined range. The controller is configured to receive a divisor, generate an address expressed in a plurality of bits according to the bits except the most significant bit of the divisor, and receive the table value corresponding to the address from the memory. The multiplier is configured to receive a dividend and calculate an initial value by multiplying the dividend and the table value corresponding to the address. Herein, the controller determines an exponent of the divisor and right-shifts the initial value by the exponent of the divisor.
    Type: Application
    Filed: August 31, 2011
    Publication date: March 15, 2012
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Dae Soon CHO, Daeho KIM
  • Publication number: 20120016532
    Abstract: Methods and a system are disclosed for one or more appliances including a controller for managing power consumption within a household. The controller is configured to receive and process a signal indicative of one or more energy parameters of an associated energy utility, including at least a peak demand period or an off-peak demand period. A generated serial number is obtained from an original serial number of the appliance or controller, which is configured for a signal to communicate to the appliance within a population and command the appliance to operate in an energy savings mode and a normal mode at various time periods. The generated serial number (GSN) is used to segregate a total population into segments to provide granularity in assigning DR activations and deactivations based upon the GSN.
    Type: Application
    Filed: July 16, 2010
    Publication date: January 19, 2012
    Inventors: Lucas Bryant Spicer, John K. Besore
  • Publication number: 20110295921
    Abstract: A hybrid greatest common divisor (GCD) calculator analyzes characteristics of polynomials and selects a particular GCD algorithm from multiple available GCD algorithms based on a combination of characteristics of the polynomials. The selected GCD algorithm is then applied to calculate the GCD of the polynomials.
    Type: Application
    Filed: May 28, 2010
    Publication date: December 1, 2011
    Applicant: Microsoft Corporation
    Inventors: Xu Yang, Xiaolin Quan, Dongmei Zhang
  • Patent number: 8056069
    Abstract: A method, computer program product, and information handling system for generating loop code to execute on Single-Instruction Multiple-Datapath (SIMD) architectures, where the loop contains multiple non-stride-one memory accesses that operate over a contiguous stream of memory is disclosed. A preferred embodiment identifies groups of isomorphic statements within a loop body where the isomorphic statements operate over a contiguous stream of memory over the iteration of the loop. Those identified statements are then converted into virtual-length vector operations. Next, the hardware's available vector length is used to determine a number of virtual-length vectors to aggregate into a single vector operation for each iteration of the loop. Finally, the aggregated, vectorized loop code is converted into SIMD operations.
    Type: Grant
    Filed: September 17, 2007
    Date of Patent: November 8, 2011
    Assignee: International Business Machines Corporation
    Inventors: Alexandre E. Eichenberger, Kai-Ting Amy Wang, Peng Wu
  • Patent number: 7991818
    Abstract: A division unit, an image analysis unit and a display apparatus using the same capable of simplifying the computation of overall average gray scale are provided. The division unit includes an adder for receiving a first to an Nth bus signals to produce an addition result, wherein the first to the Nth bus signals shift the input signal by a different number of bits and adding logic zeros to the shifted bits as compensation, where N is a positive whole number, and a multiplexer for receiving a most significant bit (MSB) of the addition result, wherein, when the MSB has a first value, the multiplexer treats P bits of the addition result as a division result, and when the MSB has a second value, the multiplexer outputs P logic 1 to serve as the division result, where P is a positive whole number.
    Type: Grant
    Filed: July 28, 2010
    Date of Patent: August 2, 2011
    Assignee: Chunghwa Picture Tubes, Ltd.
    Inventor: Tien-Chu Hsu
  • Patent number: 7986849
    Abstract: A method, system and computer program product that involves receiving and initializing a digital image. Quantization is preformed on the digital image using at least two multiplication operations. Finally, a compressed version of the digital image is presented for viewing and/or storage or transport.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: July 26, 2011
    Assignee: Oracle America, Inc.
    Inventors: Xian-Feng Kuang, Bo Liu
  • Patent number: 7921149
    Abstract: A division and square root arithmetic unit carries out a division operation of a higher radix and a square root extraction operation of a lower radix. A certain bit number (determined on the basis of a radix of an operation) of data selected from upper bits of the output of a carry save adder and the output of the adder are input to convert the data into twos complement representation data, and the twos complement representation data is shifted a certain bit number (determined on the basis of the radix of the operation) to use the shifted data for a partial remainder of the next digit. Hence, a large number of parts such as registers of a divisor and a partially extracted square root can be commonly used in a divider and a square root extractor to realize an effective and high performance arithmetic unit.
    Type: Grant
    Filed: December 13, 2005
    Date of Patent: April 5, 2011
    Assignee: NEC Corporation
    Inventor: Takahiko Uesugi
  • Publication number: 20110060786
    Abstract: A device for calculating the quotient q and remainder r of the division (y·k1+x)/k2, wherein k1 and k2 are integers and constant, and wherein x and y are integers. The device comprises a first digital circuit for receiving as input values of y and identifying corresponding values of the quotient qy and the remainder ry of the function y·k1/k2, a second digital circuit for calculating the remainder r of the division, by a) calculating a combined value (x+ry) of the remainder ry and the value of x, b) verifying if the combined value (x+ry) is less than k2, c) correcting the combined value (x+ry) if the verification indicates that the combined value (x+ry) is not less than k2, and d) assigning the corrected combined value (x+ry) to the remainder r, a third digital circuit for calculating the quotient q of the division, by a) correcting the quotient qy if the verification (2206) indicates that the combined value (x+ry) is not less than k2, and b) assigning the corrected quotient qy to the quotient q.
    Type: Application
    Filed: September 7, 2010
    Publication date: March 10, 2011
    Applicant: STMicroelectronics S.r.l.
    Inventors: Mirko Dondini, Amedeo La Scala
  • Patent number: 7895255
    Abstract: A multiplication or division operation X·K or X·1/K is performed in an electronic circuit. A software circuit area of the circuit calculates a digit shift sv such that psv is an approximate value for K. In a hardware circuit area, the value X is shifted sv digits to the left in the case of multiplication or sv digits to the right in the case of division. The software circuit area calculates a suitable correction factor Kf. The value X is multiplied by the correction factor Kf.
    Type: Grant
    Filed: November 30, 2005
    Date of Patent: February 22, 2011
    Assignee: Infineon Technologies AG
    Inventors: Christian Drewes, Ernst Bodenstorfer, Jürgen Niederholz
  • Patent number: 7895250
    Abstract: The disclosure describes a method for performing a fixed point calculation of a floating point operation (A // B) in a coding device, wherein A // B represents integer division of A divided by B rounded to a nearest integer. The method may comprise selecting an entry from a lookup table (LUT) having entries generated as an inverse function of an index B, wherein B defines a range of values that includes every DC scalar value and every quantization parameter associated with a coding standard, and calculating A // B for coding according to the coding standard based on values A, B1 and B2, wherein B1 and B2 comprise high and low portions of the selected entry of the LUT. The techniques may simplify digital signal processor (DSP) implementations of video coders, and are specifically useful for MPEG-4 coders and possibly others.
    Type: Grant
    Filed: May 25, 2005
    Date of Patent: February 22, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Shu Xiao, Junchen Du, Tao Shen
  • Patent number: 7876330
    Abstract: A technique that can contribute to improvement of processing efficiency in performing image processing employing an SIMD command is provided.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: January 25, 2011
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventor: Takahiro Hagiwara
  • Publication number: 20100332578
    Abstract: A time-invariant method and apparatus for performing modular reduction that is protected against cache-based and branch-based attacks is provided. The modular reduction technique adds no performance penalty and is side-channel resistant. The side-channel resistance is provided through the use of lazy evaluation of carry bits, elimination of data-dependent branches and use of even cache accesses for all memory references.
    Type: Application
    Filed: June 26, 2009
    Publication date: December 30, 2010
    Inventors: Vinodh Gopal, Gilbert M. Wolrich, Wajdi K. Feghali, James D. Guilford, Erdinc Ozturk, Martin G. Dixon
  • Publication number: 20100185716
    Abstract: The present invention provides an eigenvalue decomposition apparatus that can perform processing in parallel at high speed and high accuracy.
    Type: Application
    Filed: January 31, 2007
    Publication date: July 22, 2010
    Inventors: Yoshimasa Nakamura, Hiroaki Tsuboi, Taro Konda, Masashi Iwasaki, Masami Takata
  • Patent number: 7747669
    Abstract: Methods and apparatus to provide rounding of a binary integer are described. In one embodiment, a value that indicates whether a divisor divides a binary integer is extracted from a product of the binary integer and a scaled approximate reciprocal of the divisor.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: June 29, 2010
    Assignee: Intel Corporation
    Inventors: Ping Tak (Peter) Tang, John R. Harrison
  • Publication number: 20100161695
    Abstract: A system for determining the median of a plurality of data values comprises a plurality of field programmable gate arrays (FPGA), a plurality of inter FPGA links, an input router, a plurality of median modules, and a plurality of output transfer modules. Each FPGA includes a plurality of configurable logic elements and configurable storage elements from which the other components are formed. The inter FPGA link allows communication from one FPGA to another. The input router receives the plurality of data values and creates a plurality of data streams. The median module receives at least one data stream, increments a plurality of counters corresponding to a single data value within the range of data values, and determines the median by accumulating the contents of each counter. The output transfer module transfers the median to an external destination along with performance statistics of the determination of the median.
    Type: Application
    Filed: December 19, 2008
    Publication date: June 24, 2010
    Applicant: L3 COMMUNICATIONS INTEGRATED SYSTEMS, L.P.
    Inventors: Matthew R. Standfield, Jim D. Allen, Juan Esteban Flores, Michael O'Neal Fox, Deepak Prasanna, Matthew P. DeLaquil
  • Patent number: 7738657
    Abstract: The present disclosure provides a system and method for performing multi-precision division. A method according to one embodiment may include generating a first product by multiplying a modulus having a most significant bit and/or a least significant bit equal to one and a quotient approximation of the modulus. The method may also include generating the 1's complement of the first product, generating a second product by multiplying the 1's complement and the quotient approximation, normalizing and truncating the second product to obtain a quotient, and storing the quotient in memory. Of course, many alternatives, variations and modifications are possible without departing from this embodiment.
    Type: Grant
    Filed: August 31, 2006
    Date of Patent: June 15, 2010
    Assignee: Intel Corporation
    Inventors: Vinodh Gopal, Matt Bace, Gunnar Gaubatz, Gilbert M. Wolrich
  • Patent number: 7702715
    Abstract: A variable radix divider uses dividend, divisor and quotient as division operators and includes an adder/subtractor having inputs of the dividend and the divisor. The divider further includes a first and second quotient/radix generator having inputs of the dividend and the divisor, a first multiplexer having input of the output from the first quotient/radix generator, and a second multiplexer having input of the output from the second quotient/radix generator. The first and second generators each includes a prediction adder/subtractor having inputs of bits in prediction range of the dividend and bits in prediction range of the divisor, a radix generator, and a quotient generator. The radix generator and the quotient generator have input of the output of the prediction adder/subtractor. The divider iterates a recursive cycle operation until the division operation through a feedback path to the dividend is completed.
    Type: Grant
    Filed: December 30, 2005
    Date of Patent: April 20, 2010
    Assignee: Dongbu Hitek Co., Ltd.
    Inventor: Sung Youn Lee
  • Patent number: 7693929
    Abstract: An apparatus and method for allowing a digital signal processor (DSP) in a data processing system to perform high speed division operations. In one embodiment of the invention a division operation is performed in no more than two cycles. In another embodiment of the invention, the division operations are in fractional format. The data processing apparatus comprises a random access memory, a processor (12, 168), and an interface (102) coupling said random access memory (104) to said processor, said interface enables high speed division operations associated with said processor. The interface of the present invention can also be combined with a dual or co-processor system to increase the data processing efficiency.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: April 6, 2010
    Assignee: Texas Instruments Incorporated
    Inventor: Jean-Pierre Giacalone
  • Patent number: 7689642
    Abstract: One embodiment of the present invention provides a system that efficiently performs an accuracy-check computation for Newton-Raphson divide and square-root operations. During operation, the system performs Newton-Raphson iterations followed by a multiply for the divide or square-root operation. This result is then rounded to produce a proposed result. Next, the system performs an accuracy-check computation to determine whether rounding the result to a desired precision produces the correct result. This accuracy-check computation involves performing a single pass through a multiply-add pipeline to perform a multiply-add operation. During this single pass, a Booth encoding of an operand in a multiply portion of the multiply-add pipeline is modified, if necessary, to cause an additional term for the accuracy-check computation to be added to the result of the multiply-add operation.
    Type: Grant
    Filed: November 3, 2005
    Date of Patent: March 30, 2010
    Assignee: Sun Microsystems, Inc.
    Inventor: Leonard D. Rarick
  • Patent number: 7660842
    Abstract: One embodiment of the present invention provides a system that performs a carry-save division operation that divides a numerator, N, by a denominator, D, to produce an approximation of the quotient, Q=N/D. The system approximates Q by iteratively selecting an operation to perform based on higher order bits of a remainder, r, and then performing the operation, wherein the operation can include, subtracting D from r and adding a coefficient c to a quotient calculated thus far q, or adding D to r and subtracting c from q. These subtraction and addition operations maintain r and q in carry-save form, which eliminates the need for carry propagation and thereby speeds up the division operation. Furthermore, the selection logic is simpler than previous SRT division implementations, which provides another important speed up.
    Type: Grant
    Filed: May 12, 2003
    Date of Patent: February 9, 2010
    Assignee: Sun Microsystems, Inc.
    Inventors: Josephus C. Ebergen, Ivan E. Sutherland, Danny Cohen
  • Publication number: 20100011039
    Abstract: A system of equations with a Toeplitz coefficient matrix [T] can be efficiently solved by approximating the coefficient matrix [T] with an approximately Toeplitz coefficient matrix [Tapp] that can be efficiently transformed to a banded form. The system of equations with the banded coefficient matrix is then efficiently solved and this solution is used to obtain the solution to the original system of equations with the Toeplitz coefficient matrix [T].
    Type: Application
    Filed: July 11, 2008
    Publication date: January 14, 2010
    Inventor: James Vannucci
  • Publication number: 20090248770
    Abstract: Methods and apparatus which reduce or completely eliminate non-shift based divisions as part of estimating transmitted symbols and/or generating slicing parameters corresponding to two symbol transmission streams in a wireless communication system are described. A linear least squares error estimation filtering module performs symbol estimations and/or slicing parameter generation while avoiding non-shift based division operations. The linear least squares estimation module generates intermediate parameters, and implements equations which facilitate symbol estimation utilizing shift based divisions while avoiding non-shift based divisions.
    Type: Application
    Filed: March 26, 2009
    Publication date: October 1, 2009
    Applicant: QUALCOMM INCORPORATED
    Inventors: Siddharth Ray, Sundeep Rangan
  • Publication number: 20090248780
    Abstract: A data processing system 2 includes an instruction decoder 22 responsive to polynomial divide instructions DIVL.PN to generate control signals that control processing circuitry 26 to perform a polynomial division operation. The denominator polynomial is represented by a denominator value stored within a register with an assumption that the highest degree term of the polynomial always has a coefficient of “1” such that this coefficient need not be stored within the register storing the denominator value and accordingly the denominator polynomial may have a degree one higher than would be possible with the bit space within the register storing the denominator value alone. The polynomial divide instruction returns a quotient value and a remainder value respectively representing the quotient polynomial and the remainder polynomial.
    Type: Application
    Filed: February 23, 2009
    Publication date: October 1, 2009
    Applicant: ARM LIMITED
    Inventors: Dominic H. Symes, Daniel Kershaw, Martinus C. Wezelenburg
  • Publication number: 20090228353
    Abstract: Methods are provided for the classification of search engine queries and associated documents based on search engine query click logs. One or more seed documents or queries are provided that contain content that is representative of a category. A query click log containing information regarding queries entered by at least one user into the search engine and documents subsequently clicked in search engine results corresponding with the queries is analyzed to determine which one or more queries resulted in clicks on the seed documents. Information is stored associating the one or more queries with the category if they resulted in clicks on the seed documents.
    Type: Application
    Filed: March 5, 2008
    Publication date: September 10, 2009
    Applicant: MICROSOFT CORPORATION
    Inventors: KANNAN ACHAN, ARIEL FUXMAN, RAKESH AGRAWAL, PANAYIOTIS TSAPARAS
  • Patent number: 7584237
    Abstract: A method and mechanism for performing division. A processor includes a divider configured to perform arithmetic division operations. Prior to dividing a dividend by a divisor, the divider manipulates the dividend and divisor to reduce the number of bits considered and the computations required to perform the division. The divisor is normalized by eliminating sign bits. The dividend is prescaled to eliminate one or more sign bits. Prescaling of the dividend may not be precise as sign bits of the dividend may be shifted out as groups of bits, rather than individual bits. Prescaling of the dividend may be adjusted to account for the fact that the divider considers multiple bits of the dividend at a time. Subsequent to prescaling and adjustment, the dividend may be adjusted in dependence upon the normalization of the divisor. Further adjustment may be utilized to maintain a significance relationship between the divisor and dividend. Subsequent to further adjustment, the division operation may be completed.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: September 1, 2009
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Teik-Chung Tan, Michael Tuuk, Wing-Shek Wong
  • Publication number: 20090216825
    Abstract: A method, computer program product and a system for detecting errors in a result of a fixed-point division operation are provided. The method includes: receiving a result of a fixed-point division operation for a dividend and a divisor; performing a first comparison of the divisor and a remainder of the result; performing a second comparison of a sign of the dividend and a sign of the remainder; and determining whether the result is correct based on the first comparison and the second comparison.
    Type: Application
    Filed: February 26, 2008
    Publication date: August 27, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Joshua M. Weinberg, Martin S. Schmookler
  • Publication number: 20090193066
    Abstract: A dividing unit sets an actual packet length transferred from a packet receiving section to a variable U, and then sets 2? to a variable V. If a positive number determining section determines that a subtraction result of subtracting a remainder N0 from a quotient M0, both found by dividing U by V, is a positive number, the dividing unit overwrites the subtraction result to U. The dividing unit repeats such operations of dividing the subtraction result by V, until the positive number determining section determines that the subtraction result of subtracting the remainder from the quotient, both found by dividing U by V, is a non-positive number. When the subtraction result becomes a non-positive number and the quotient and the remainder match, a packet length determining section determines that received data has a normal size, and notifies it to a discard determining section.
    Type: Application
    Filed: January 28, 2009
    Publication date: July 30, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Fuyuta SATO, Hideo Okawa
  • Patent number: 7567999
    Abstract: A device for calculating a result or an integer multiple of the result of a division of a numerator by a denominator includes a unit for providing a factor which is selected such that a product of the factor and the denominator is greater than the result. The device further includes a unit for modularly reducing a first product of the numerator and the factor using a modulus equaling a sum of a second product of the denominator and the factor and of an integer to obtain an auxiliary quantity having the result. A unit is used to extract the result or the integer multiple of the result from the auxiliary quantity. A division is thus reduced to a modular reduction and an extraction which is uncomplicated as far as calculation is concerned so that, in particular in long-number division tasks, the speed on the one hand and the safety on the other hand are increased.
    Type: Grant
    Filed: August 12, 2004
    Date of Patent: July 28, 2009
    Assignee: Infineon Technologies AG
    Inventor: Wieland Fischer
  • Patent number: 7539720
    Abstract: A method and device divides a dividend by a divisor, the dividend and the divisor both being integers. The method and device determine a maximum possible number of quotient digits (NDQ) based on a number of significant digits of the divisor and the dividend, normalizes the dividend and divisor, and calculates NDQ number of quotient digits from the normalized divisor and dividend.
    Type: Grant
    Filed: December 15, 2004
    Date of Patent: May 26, 2009
    Assignee: Sun Microsystems, Inc.
    Inventors: Christopher H. Olson, Jeffrey S. Brooks, Paul J. Jagodik
  • Patent number: 7523152
    Abstract: A method for an extended precision integer divide algorithm includes separating an L-bit integer dividend into two equal width integer format portions, a first portion including lower M bits of the integer dividend and a second portion including upper M bits of the integer dividend, where M is equal to ½ L. An N-bit wide integer divisor is converted from an integer format into a floating point format divisor. The first integer portion is converted into a floating point format and divided by the floating point format divisor to obtain a first floating point quotient, which is converted into a first integer format quotient. The second integer portion is converted into a floating point format and divided by the floating point format divisor to obtain a second floating point quotient which is also converted to a second integer format quotient. Then first and second integer format quotients are summed together to generate a third integer format quotient.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: April 21, 2009
    Assignee: Intel Corporation
    Inventors: Patrice L. Roussel, Rajesh S. Parthasarathy
  • Patent number: 7516172
    Abstract: A fast division method which uses a smaller quotient digit set of {?1, 1} than {?1, 0, 1} that is used by known algorithms, therefore accelerates the speed of calculation. Partial remainders can be computed with the signals of remainders decided independently and in parallel. By taking the absolute values of the remainders, we can successively subtract the remainders without the need of knowing the signs of remainders, while signs of the remainders can be decided in parallel and independently at the same time. The algorithm adopts non-restoring division operation and CSA type of operation for fast subtraction. The algorithm is also an on-line algorithm that facilitates highly pipelined operation while it is much simpler than the existing on-line algorithms.
    Type: Grant
    Filed: August 2, 1995
    Date of Patent: April 7, 2009
    Assignee: United Microelectronics Corp.
    Inventors: Sau-Gee Chen, Chieh-Chih Li
  • Publication number: 20090089346
    Abstract: A method for performing a division operation in a system includes a) determining an approximate quotient of a numerator value and a denominator value; b) determining an initial error of the approximate quotient; c) determining a quotient adjustment value based on the initial error; d) determining whether to apply the quotient adjustment value to the approximate quotient; e) if the determination at d) is YES, then applying the quotient adjustment value to the approximate quotient; f) determining an iterative error of the approximate quotient; g) updating the quotient adjustment value based on the iterative error; h) repeating acts d) through g) until the determination at d) is NO, thereby determining a final value for the approximate quotient; i) generating an integer quotient based on the final value of the approximate quotient; and j) using the integer quotient with regard to at least one aspect of the system.
    Type: Application
    Filed: September 28, 2007
    Publication date: April 2, 2009
    Inventors: James Ray Bailey, Zachary Nathan Fister, Jimmy Daniel Moore, JR.
  • Patent number: 7486789
    Abstract: In scalar multiplication method using a Montgomery-type elliptic curve, a high-speed elliptic curve calculation device effectively uses a table that stores coordinates of certain scalar multiple points like points multiplied by exponentiation of two to a certain point G and so forth. The elliptic curve calculation device receives an arbitrary integer k of n bits and outputs scalar-multiplied points against a point G on a Montgomery-type elliptic curve E on a finite field F that is given in advance. The elliptic curve calculation device includes a calculation procedure generation unit that generates a calculation procedure that addition on the elliptic curve E with either of G, 2 *G, 22*G., . . .
    Type: Grant
    Filed: December 9, 2002
    Date of Patent: February 3, 2009
    Assignee: Panasonic Corporation
    Inventors: Yuichi Futa, Motoji Ohmori