Abstract: A programmable logic device includes at least one RAM block generating a first multi-bit calculation result which may, but does not necessarily, involve a multiplication of two operands. A shift operation is driven by a second multi-bit calculation result shifts the second multi-bit calculation result by at least one bit to generate a shifted second multi-bit calculation result. A multi-bit adder coupled to the at least one RAM block adds the shifted second multi-bit calculation result to the first multi-bit calculation result.

Abstract: A computerized device has dynamically modifiable hardware, such as an ASIC, that performs queue-scheduling operations. The hardware incorporates a generic sorting processor (GSP) that is dynamically configurable to implement various sorting algorithms to meet specific queue scheduling requirements for the computerized device. The computerized device extracts a first time stamp value and a second time stamp value associated with a first queue and a second queue, respectively. The computerized device receives instructions to configure a table of the GSP with scheduling entries. The computerized device compares the first time stamp value with the second time stamp value to form a comparison result. The computerized device then selects a decision instruction from the table, based upon the comparison result, and identifies a preferred queue of the first queue and the second queue, based upon the decision instruction.

Abstract: An adder for adding a signal at a first input (A) and a second input (B) to produce an adder output (S) is disclosed. The adder comprises a bypass input (bypass) and a logic circuit, communicatively coupled to the bypass input (bypass), the first input (A), and the second input (B), the logic circuit configured to hold at least one of the first input (A) and the second input (B) according to the bypass input (bypass).

Abstract: An apparatus for generating a plurality of counts is provided. A first adder is coupled to receive n least significant bits of a base count and a plurality of signals indicative of a plurality of values to be added to the base count, each of the plurality of values corresponding to one of a plurality of counts to be generated. The first adder generates, for each of the plurality of counts, n least significant bits of the count, and generates a plurality of carry signals. A second adder is coupled to receive most significant bits of the base count and the plurality of carry signals. The second adder generates, for each of the plurality of counts, most significant bits of the count.

Abstract: A fixed-point arithmetic unit comprises a plurality of full-adders and half-adders arranged in at least an input row and an output row. A plurality of inputs to the input row is arranged to receive bits comprising a sparse-redundant representation of the integer. A converter converts 1-redundant representations of the integer to the space (1/K)-redundant representations. A process is described to design rows of a multiplier by identifying a distribution of multiplication product groups, and transforming the distribution of multiplication product groups to adders to occupy a highest unoccupied row of the multiplier.

Abstract: An objective is to obtain a Jacobian group element adder that can calculate addition in a Jacobian group of a Cab curve at a high speed, and can enhance practicality of the Cab curve. An algebraic curve parameter file A 10, and Groebner bases I1 and I2 of ideals of a coordinate ring of an algebraic curve designated by this file A are input into an ideal composition section 11 to perform arithmetic of producing a Groebner basis J of an ideal product of the ideal generated by I1 and ideal generated by I2. In a first ideal reduction section 12, arithmetic is performed of producing a Groebner basis J* of an ideal that is smallest in a monomial order designated by the file A among ideals equivalent to an inverse ideal of an ideal that J in the coordinate ring of the algebraic curve designated by the file A generates.

Abstract: The embodiments of the present invention relate to the general area of the Field Programmable Gate Arrays, and, in particular to the architecture and the structure of the building blocks of the Field Programmable Gate Arrays. The proposed logic units, as separate units or cluster of units, which are mainly comprised of look-up tables, multiplexers, and a latch, implement functions such as addition, subtraction, multiplication, and can perform as shift registers, finite state machines, multiplexers, accumulators, counters, multi-level random logic, and look-up tables, among other functions. Having two outputs, the embodiments of the logic unit can operate in split-mode and perform two separate logic and/or arithmetic functions at the same time. Clusters of the proposed logic units, which utilize local interconnections instead of traditional routing channels, add to efficiency, speed, and reduce required real estate.

Abstract: A parallel-prefix modulo 2n?1 adder that is as fast as the fastest parallel prefix 2n integer adders, does not require an extra level of logic to generate the carry values, and has a very regular structure to which pipeline registers can easily be added. All nodes of the adder have a fanout ?2. In the prefix structure of the adder, each carry value term output by the parallel prefix structure is determined by the all of the bits in the operands input to the adder. In one embodiment, there are log2 n stages in the prefix structure. Each stage has n logical operators, and all of the logical operators in the prefix structure are of the same kind. Pipeline registers may be inserted before and/or after a stage in the prefix structure.

Abstract: New instruction definitions for a packet add (PADD) operation and for a single instruction multiple add (SMAD) operation are disclosed. In addition, a new dedicated PADD logic device that performs the PADD operation in about one to two processor clock cycles is disclosed. Also, a new dedicated SMAD logic device that performs a single instruction multiple data add (SMAD) operation in about one to two clock cycles is disclosed.

Abstract: An extension of the serial/parallel Montgomery modular multiplication method with simultaneous reduction as previously implemented by the applicants, adapted innovatively to perform both in the prime number and in the GF(2q) polynomial based number field, in such a way as to simplify the flow of operands, by performing a multiple anticipatory function to enhance the previous modular multiplication procedures.

Abstract: A logic circuit includes a first series of logic elements. Each logic element has a look-up table (LUT) and a dedicated adder to implement an arithmetic mode in the logic element. The logic circuit also includes a carry chain connecting the first series of logic element, and an initialization circuit connected to the carry chain to initialize the carry chain.

Abstract: An apparatus and method for performing fast arithmetic operations, including addition, in a pipelined circuit is described. The apparatus and method operating on a first binary number and a second binary number comprise: a first arithmetic logic unit (ALU) operating on a first lower portion of the first binary number and a second lower portion of the second binary number to produce a first result and a carry out signal; and a second ALU operating on a first upper portion of the first binary number and a second upper portion of the second binary number to produce a second result; wherein at least a portion of the pipelined circuit stalls in response to the carry out signal. Another embodiment includes memory comprising a plurality of words, each word comprising data bits and a flag bit indicating a predetermined number of the most significant data bits are all zero.

Abstract: Signals obtained from a sensor array that includes a plurality of energy transducers are processed. A converter used in this processing generates a plurality of converted signals by applying processing to signals from the energy transducers on a block by block basis, wherein the block is a sensor block comprising a prescribed number of neighboring energy transducers. The plurality of converted signals generated by the converter include a first converted signal, which includes a local mean and is generated by adding signals obtained from the sensor block, and a second converted signal, which includes difference between signals obtained from the sensor block. The converted signals produced by the converter are output simultaneously or sequentially.

Abstract: The present invention provides an efficient implementation of multiprecision arithmetic, such as for a microprocessor. For example, an implementation of multiprecision arithmetic is provided that eliminates condition codes, such as condition codes for a carry bit and a borrow bit, and eliminates an add-with-carry instruction for multiprecision addition and a subtract-with-borrow instruction for multiprecision subtraction. In one embodiment, a method includes separately performing a first one or more arithmetic operations and a second one or more arithmetic operations. The second arithmetic operations indicate if the first arithmetic operations cause a carry condition or if the first arithmetic operations cause a borrow condition. The one or more results of the first and second arithmetic operations are then provided. The first and second arithmetic operations can be executed in parallel on a microprocessor.

Abstract: A method of factoring numbers in a non-binary computation scheme and more particularly, a method of factoring numbers utilizing a digital multistate phase change material. The method includes providing energy in an amount characteristic of the number to be factored to a phase change material programmed according to a potential factor of the number. The programming strategy provides for the setting of the phase change material once for each time a multiple of a potential factor is present in the number to be factored. By counting the number of multiples and assessing the state of the phase change material upon execution of the method, a determination of whether a potential factor is indeed a factor may be made. A given volume of phase change material may be reprogrammed for different factors or separate volumes of phase change material may be employed for different factors.

Abstract: A programmable logic device includes at least one RAM block generating a first multi-bit calculation result which may, but does not necessarily, involve a multiplication of two operands. A shift operation is driven by a second multi-bit calculation result shifts the second multi-bit calculation result by at least one bit to generate a shifted second multi-bit calculation result. A multi-bit adder coupled to the at least one RAM block adds the shifted second multi-bit calculation result to the first multi-bit calculation result.

Abstract: An address generating circuit, in which address generation by a modulo addition is executed at high speed, is provided. The address generating circuit makes, a two input adder that adds an address and a renewing step, a three input adder and subtracter that adds the address and the renewing step and further adds the size of a modulo area to this added result or subtracts the size of the modulo area from this added result, and a selection judging circuit that generates a selection signal for selecting one of the outputs from the two input adder and the three input adder and subtracter, work in parallel and independently. And a multiplexer selects one of the outputted results from the two input adder and the three input adder and subtracter based on the selection signal from the selection judging circuit.

Abstract: An address translation logic and method for generating an instruction's operand address. The address generation logic includes an address generation circuit having adders that perform partial sum additions of the instruction operand's base register value with a displacement value in the instruction. The address generation logic also includes a carry prediction history block associated with the instruction that provides predicted carry-in values to the adders during the partial sum addition operation. In a related embodiment, the carry prediction history block that, in an advantageous embodiment, is appended to the instruction includes a predicted row access select (RAS) carry-in value, a predicted column access select (CAS) carry-in value and a confirmation flag that indicates whether the previous carry-in predictions for the previous predicted RAS and CAS carry-in values for the instruction were correct.

Abstract: An addition circuit for digital data includes a digital adder for the addition of digital input data values present at data inputs of the digital adder to form a summation output data value, at an output of the digital adder. The data inputs have a predetermined data bit width n. A saturation circuit for limits the summation output data value present at a data input of the saturation circuit to be within a range determined by an upper threshold data value and a lower threshold data value. The n?m least significant data bits of the summation output data value are present directly at the data input of the saturation circuit, whereas the m most significant data bits of the summation output data value are switched through to the data input of the saturation circuit via a clock-state-controlled latch register.

Abstract: A method and system for performing floating point additive arithmetic operations of long operands in a narrow dataflow. The operands include first and second floating point numbers having first and second mantissas, respectively, the second operand greater than the first operand. The mantissas are both separated into a low portion and a high portion, the high portions are loaded into N-bit operand registers. The high portion of the first mantissa is aligned with respect to the high portion of the second mantissa, the high portions are then moved into 2N-bit registers. The low portion of the first mantissa is aligned in accordance with the alignment of the first mantissa high portion. The low portions of both mantissas are then concatenated into the registers, the first mantissa concatenated using a hold-function circuit. A 2N-bit-wide adder performs the additive arithmetic operation on the concatenated mantissas.

Abstract: A function block allows a multiplier and a multi-input multiplexer to be realized with a small number of blocks. A logical function generator generates a logical output signal from first to fourth logical inputs thereof according to a logical function selected from a plurality of 4-input/1-output logical functions depending on configuration data. A 4-2 carry block generates a 4-2 carry output from the second to fourth logical inputs. A first signal is generated from at least the logical output, a second signal from at least the first logical input, a third signal from at least a 4-2 carry input signal, and a fourth signal from at least the 4-2 carry input signal. A multiplexer selects one of the second and third signals depending on the first signal to produce a carry output signal. An exclusive OR circuit produce an exclusive-ORed result from the logical output and the fourth signal.

Abstract: A method and apparatus for integer rounding are described herein. In one embodiment, exemplary method includes adding a first value with a first constant, resulting in a second value, optionally performing a rounding operation on the second value, resulting in a third value, and extracting at least a portion of bits from the third value to generate an integer component corresponding to the first value, the first constant being selected such that an accuracy of the integer component is independent of a rounding mode of the rounding operation. Other methods and apparatuses are also described.

Abstract: A method of performing in-place arithmetic, particularly addition and subtraction, on numbers stored in respective consecutive rows of an array processor that has two tags registers. In a first machine cycle per bit, results of logical operations are stored in the tags registers, and the tags registers are shifted to align the intermediate results with other rows. In a second machine cycle per bit, results of further logical operations are stored in the tags registers, and the tags registers are shifted back to align the new intermediate results with the original rows.

Abstract: A high-frequency compound instruction mechanism and method allows performing a common compare immediate function before an add function has completed, thereby reducing the number of cycles to perform the add-compare function. By increasing the speed of performing the add-compare function, a branch mispredict signal may be provided to an instruction pipeline before data registers are affected by the pipelined instructions. The compound instruction mechanism of the preferred embodiments may be implemented within space that is primarily unused within arithmetic logic units, resulting in an implementation that only marginally increases space requirements on an integrated circuit.

Abstract: Embodiments of the present invention generally relate to an adder. In embodiments, the adder may include two adder circuits which each process a segment of a first number and a second number. The second adder, for processing the higher order digits, may be operated at a lower voltage supply level than the first adder for processing lower order digits. Accordingly, power savings may be accomplished with a nominal time delay penalty.

Abstract: Embodiments of the present invention generally relate to logic circuitry that implements both static logic and dynamic logic. In embodiments, static logic is implemented for functions which are non-performance critical and dynamic logic is implemented for functions that are performance critical. Accordingly, power savings can be realized.

Abstract: A method of formulating and solving equations that facilitate recognition of full word saturating addition and subtraction The method includes formulating, for each basis addition statement z=x+y or subtraction statement z=x−y, data flow equations that describe properties of the program statements being analyzed; and solving the data flow equations. The properties may include: (a) the values BITS of program variables as Boolean functions of the sign bits of x, y and z; (b) the condition COND under which program statements are executed as Boolean functions of the sign bits of x, y and z; and (c) the condition REACH of which values of variables reach any given use of z when overflow/underflow/neither occurs.

Abstract: Methods of adding and subtracting sets of binary numbers using an associative processor. The inner loop over corresponding bits of the operands is executed in only three machine cycles. Only the carry bit of each loop iteration is carried forward to the next loop iteration. At most five logical operations are used per loop iteration for addition, and at most seven logical operations, of which at most five are binary logical operations, are used per loop iteration for subtraction. In each loop iteration, the second input bit is a direct or indirect argument of at most three logical operations in addition, and of at most four logical operations in subtraction. Each loop iteration includes at least one OR operation and at most two XOR operations.

Abstract: A method and apparatus is disclosed that uses an arithmetic circuit for adding numbers represented in redundant form to subtract numbers received in redundant form, including numbers received from a bypass circuit. The method includes generating a complemented redundant form of at least one number supplied to the arithmetic circuit in redundant form. It also includes providing an adjustment input to the arithmetic circuit to augment a result produced through the arithmetic circuit to generate a valid outcome in redundant form of a subtraction operation. A carry-save adder structure is used in one preferred embodiment of the current invention to perform a subtraction operation A−B, where B is a number represented by one of its valid carry-sum redundant representations. In order to perform the subtraction operation, each of the carry bits and each of the sum bits in a redundant representation of B are complemented and supplied to the carry-save adder.

Abstract: Using a subtraction without borrow operation, the first operand lowest order word is subtracted from a second operand lowest order word. If the result of the subtracting is not zero, then a zero (Z) flag is cleared such that a Z flag status is not set. If, however, the result of the subtracting is zero, then the Z flag is set as usual. Next, a first operand next higher order word is subtracted from a second operand next higher order word using a subtraction with borrow and a sticky not Z flag (SBBZ) instruction and, based upon the subtracting, the Z flag is updated accordingly such that it represents the result of the whole multi-word subtraction until the first operand highest order word is subtracted from the second operand highest order word. The comparing of the first operand and the second operand is then based upon the Z flag status, if needed, after the subtraction of the first operand highest order word is subtracted from the second operand highest order word.

Abstract: A method of factoring numbers in a non-binary computation scheme and more particularly, a method of factoring numbers utilizing a digital multistate phase change material. The method includes providing energy in an amount characteristic of the number to be factored to a phase change material programmed according to a potential factor of the number. The programming strategy provides for the setting of the phase change material once for each time a multiple of a potential factor is present in the number to be factored. By counting the number of multiples and assessing the state of the phase change material upon execution of the method, a determination of whether a potential factor is indeed a factor may be made. A given volume of phase change material may be reprogrammed for different factors or separate volumes of phase change material may be employed for different factors.

Abstract: An integrated circuit has a command/control bus and a number of processing elements. The processing elements contain a number of parts, each part being connected to said command/control bus. Each one of the processing elements is re-configurable in response to commands on said command/control bus to provide any one of a plurality of different arithmetic operations.

Abstract: One embodiment of the present invention provides a system for compiling computer code to perform a subtraction operation between a first interval and a third interval to produce a resulting interval. The system operates by receiving source code within a compiler. The system next determines if a subtraction operation within the source code is a dependent subtraction operation, wherein the third interval is the sum of the first interval and a second interval. If so, the system produces executable code for the subtraction operation that computes a left endpoint for the resulting interval and a right endpoint for the resulting interval. If the left endpoint of the third interval is negative infinity, the left endpoint of the resulting interval is assigned to be negative infinity.

Abstract: The present invention relates to a method and system for providing a single accumulatable packed multi-way addition instruction having the functionality of multiple instructions without causing any timing problems in the execute stage. Specifically, the accumulatable packed multi-way combination instruction may be associated with at least one destination and a plurality of operands and set a polarity of each of a plurality of source operands derived from the plurality of operands, if requested by the instruction. The instruction also may add selected pairs of the plurality of source operands in predetermined orders to obtain at least one result and, if requested by the instruction, accumulating the plurality of results to obtain at least one accumulated result; output at least one predetermined pair of the at least one result and the at least one accumulated result; and accumulate condition codes for each of the at least one result and the at least one accumulated result, if requested by the instruction.

Abstract: Methods of adding and subtracting sets of binary numbers using an associative processor. The inner loop over corresponding bits of the operands is executed in only three machine cycles. Only the carry bit of each loop iteration is carried forward to the next loop iteration. At most five logical operations are used per loop iteration for addition, and at most seven logical operations, of which at most five are binary logical operations, are used per loop iteration for subtraction. In each loop iteration, the second input bit is a direct or indirect argument of at most three logical operations in addition, and of at most four logical operations in subtraction. Each loop iteration includes at least one OR operation and at most two XOR operations.

Abstract: An apparatus for generating a plurality of counts is provided. A first adder is coupled to receive n least significant bits of a base count and a plurality of signals indicative of a plurality of values to be added to the base count, each of the plurality of values corresponding to one of a plurality of counts to be generated. The first adder generates, for each of the plurality of counts, n least significant bits of the count, and generates a plurality of carry signals. A second adder is coupled to receive most significant bits of the base count and the plurality of carry signals. The second adder generates, for each of the plurality of counts, most significant bits of the count.

Abstract: A technique for physically implementing a running sum adder network and configuring the concomitant adder network of elements. A 2k+1×2k+1 adder network has the size 2k+2−k−3 and depth 2k+1; thus the adder network achieves a very good balance between the measures of size. The adder network utilizes a systematic design method based upon a recursive construction algorithm.

Abstract: An apparatus and method for performing fast arithmetic operations, including addition, in a pipelined circuit is described. The apparatus and method operating on a first binary number and a second binary number comprise: a first arithmetic logic unit (ALU) operating on a first lower portion of the first binary number and a second lower portion of the second binary number to produce a first result and a carry out signal; and a second ALU operating on a first upper portion of the first binary number and a second upper portion of the second binary number to produce a second result; wherein at least a portion of the pipelined circuit stalls in response to the carry out signal. Another embodiment includes memory comprising a plurality of words, each word comprising data bits and a flag bit indicating a predetermined number of the most significant data bits are all zero.

Abstract: Flexible VLSI architecture implements of MPEG video processing unit (VPU) for encoding and decoding. In encoding mode, VPU performs compression operations on digitized video input per MPEG standard; and in decoding mode, VPU performs decompression operations on video bitstream per MPEG standard. VPU modules include: Discrete Cosine Transformation (DCT), Inverse Discrete Cosine Transformation (IDCT), Quantization (QNT), Inverse Quantization (IQ), Variable Length Encoding (VLC), Variable Length Decoding (VLD) and Motion Compensation (MC). VPU functions in half duplex, and hardware modules are shared between encode/decode modes. Architecture provides low-cost, flexible and efficient solution to implement real-time MPEG codec. Specific system configuration is not required, and general interface supports various operating conditions.

Abstract: A processing engine 10 provides computation of an output vector as a linear combination of N input vectors with N coefficients in an efficient manner. The processing engine includes a coefficient register 940 for holding a representation of each of N coefficients of a first input vector. A test unit 950 is provided for testing selected parts (e.g. bits) of the coefficient register for respective coefficient representations. An arithmetic unit 970 computes respective coordinates of an output vector by selective addition/subtraction of coordinates of a second input vector dependent on results of the coefficient representation tests. Power consumption can be kept low due to the use of a coefficient test operation in parallel with an ALU operation.

Abstract: Adder circuitry is provided based on a reduced mathematical method to provide high-speed hexadecimal addition. A first adder adds the least significant binary digits of two hexadecimal numbers to provide a Digit1 and a Dot1, and a second adder adds the second least significant binary digits to provide a Digit2 plus a Dot1 as a Sum2 and a CarryA. A secondary adder adds the Dot1 and the Sum2 to provide the sum of Digit2 plus Dot2 and Dot1 as a SumA. A generator generates a Dot2 of hexadecimal “1” for certain values of the Sum2 and the CarryA, and a detector triggers an output device, which outputs a hexadecimal “0”, to output the Dot2 in response to a certain pattern of hexadcecimal numbers in the Dot1 and the Sum2. Thus, the least signifigant digit of the added hexadecimal numbers is Digit1, the second least significant digit is SumA, and the third least significant digit is the output of the output device.

Abstract: A method for performing prefix sums, by including a prefix sum instruction in the instruction set of a microprocessor. Both general prefix summation, base-zero prefix summation and base-zero suffix summation are included in the scope of the present invention. The prefix sum instruction may be implemented in software, using the instructions of existing instruction sets, or may be implemented in dedicated hardware, for example, as a functional unit of a microprocessor. The hardware implementation is suitable for application to the allocation of computational resources among concurrent tasks. The scope of the present invention includes one such application: guaranteeing conflict-free access to multiple single-ported register files.

Abstract: Using a subtraction without borrow operation, the first operand lowest order word is subtracted from a second operand lowest order word. If the result of the subtracting is not zero, then a zero (Z) flag is cleared such that a Z flag status is not set. If, however, the result of the subtracting is zero, then the Z flag is set as usual. Next, a first operand next higher order word is subtracted from a second operand next higher order word using a subtraction with borrow and a sticky not Z flag (SBBZ) instruction and, based upon the subtracting, the Z flag is updated accordingly such that it represents the result of the whole multi-word subtraction until the first operand highest order word is subtracted from the second operand highest order word. The comparing of the first operand and the second operand is then based upon the Z flag status, if needed, after the subtraction of the first operand highest order word is subtracted from the second operand highest order word.

Abstract: An adder logic circuit for performing an addition operation of a first numerical value and a second numerical value having a bit width narrower than that of the first numerical value is described.

Abstract: Disclosed is a semiconductor computing circuit achievable with simple circuitry and capable of performing analog computations at high speed to compute an absolute-value voltage representing the difference between a first signal voltage and a second signal voltage.

Abstract: A triggerable, pipelined 40-bit high speed accumulator includes trigger and continuous modes which can be operated at 50 MHz clock frequency. The high speed accumulator can be combined with static random access memory (SRAM) so as to be applied to digital frequency synthesizer, function generator and arbitrary waveform generator, etc. The high speed accumulator has two operation modes-trigger mode and continuous mode. Under trigger mode, the accumulator waits for a trigger signal to initiate its operation, while under continuous mode, the accumulator works without any trigger signal.

Abstract: In one embodiment, a modulo addressing unit for a processor is described that includes a plurality of adders to generate an uncorrected target module address and at least one corrected target module address in parallel. A comparator selects one of the target module addresses a function of a base address (b) for a circular buffer, a length (L) of the circular buffer, an index address (I) and a modifier value (M). In one embodiment the comparator selects a first corrected target module address when I+M<B, a second corrected target module address when I+M>=B+L and an uncorrected module address when B<=I+M<B+L.

Abstract: A method and apparatus for performing a divide operation in a computer are described. The apparatus includes a first memory containing estimated reciprocal terms, and a second memory containing reciprocal error terms. An adder adds a selected estimated reciprocal term from the first memory and a selected reciprocal error term from the second memory to provide the reciprocal. The selected estimated reciprocal term and the selected reciprocal error term correspond to at least a portion of a divisor. The apparatus includes a multiplier for multiplying a dividend by the reciprocal to generate a quotient. The method includes the step of looking up an estimated reciprocal term in a first lookup table stored in a first computer memory wherein the estimated reciprocal term corresponds to at least a portion of a given divisor. A reciprocal error term is looked up in a second lookup table stored in a second computer memory, the error term corresponds to at least a portion of the divisor.

Abstract: A technique for receiving a first data from a storage location in which the first data is not stored fully aligned within processor data boundaries for data retrieval. The adder also receives a second data having its alignment adjusted to correspond to the first data and adds the first data and the second data in CPU unaligned format. A carry control circuit coupled to the adder determines which carries are selected for transfer to the next stage for calculating a sum of the two data.

Abstract: An adder comprises: a comparator circuit 2 for comparing values of n input signals, each of which comprises 1-bit data, with first to n-th predetermined values which are different from each other; a non-volatile memory 6 having first to n+1-th word lines, m (2m≧n+1) bit lines which are provided so as to intersect the word lines, and memory cells, each of which is provided at an intersection of each of the word lines and each of the bit lines and each of which has stored 1-bit data; and a selector circuit 4 for selecting one of the n+1 word lines on the basis of n comparison results of the comparator circuit to activate the selected word line. Thus, a plurality of bits are added at high speed.