摘要:
A zero/one anticipator having an integrated sign selector is disclosed. A leading zeros string and a leading ones string are generated by examining carry propagates, generates, and kills of two adjacent bits of two input operands to an adder within a floating-point processor. The leading zeros string is for a positive sum, and the leading ones string is for a negative sum. A normalization shift amount is then determined from the leading zeros string and the leading ones string. A sign of a sum of the two input operands is then determined separately but concurrently with the normalization shift amount determination process. The sign is then utilized to select either the positive sum or the negative sum for a proper normalization shift amount.
摘要:
A low latency fused multiply-adder for adding a product of a first binary number and a second binary number to a third binary number is disclosed. The low latency fused multiply-adder includes a partial product generation module, a partial product reduction module, and a carry propagate adder. The partial product generation module generates a set of partial products from the first binary number and the second binary number. Coupled to the partial product generation module, the partial product reduction module combines the set of partial products with the third binary number to produce a redundant Sum and a redundant Carry. Finally, the carry propagate adder adds the redundant Sum and the redundant Carry to yield a Sum Total.
摘要:
A high-speed carry-lookahead binary adder is disclosed. The binary adder includes multiple rows of carry-lookahead circuits, a half-sum module, and a sum/carry module. A first carry-lookahead circuit row includes multiple eight-bit group generate circuits and multiple eight-bit group propagate circuits. Each of the eight-bit group generate circuits produces a generate signal for a corresponding bit location. Each of the eight-bit group propagate circuits produces a propagate signal for a corresponding bit location. The half-sum module is utilized to generate a half-sum signal. By utilizing the half-sum signal, the generate signals, and the propagate signals, the sum/carry module generates sum signals and a carry signal.
摘要:
A 6-to-3 carry-save binary adder is disclosed. The 6-to-3 carry-save adder includes a means for receiving six data inputs and a means for simultaneously adding the six data inputs to generate a first data output, a second data output, and a third data output. The first data output is a SUM output, the second data output is a CARRY—2 output, and the third data output is a CARRY—4 output.
摘要:
A method for anticipating leading zeros/ones in a floating-point processor is disclosed. A leading zeros string and a leading ones string is generated by examining carry propagates, generates, and kills of two adjacent bits of two input operands to an adder within a floating-point processor. The leading zeros string is for a positive sum, and the leading ones string is for a negative sum. A normalization shift amount is calculated directly and concurrently from the leading zeros string and the leading ones strings prior to a determination of a sign of an output of the positive sum and the negative sum.
摘要:
A 64-bit comparator includes a first stage for receiving a 64-bit number A and a 64-bit number B, and generating first output values. A second stage then receives the first output values from the first stage and outputs second output values, and a third stage receives the second output values from the second stage and outputs greater than, less than, and equivalent values. Thus, the comparator is faster in that it is implemented in three logic stages by making efficient use of compound dynamic gates.
摘要:
A dual mode rotator capable of performing 32-bit and 64-bit rotation. According to a preferred embodiment, the dual mode rotator includes a first, second, and third rotator units wherein each rotator has a plurality of inputs and outputs. The inputs of the second rotator are operatively connected to the corresponding outputs of the first rotator unit. The inputs of the third rotator unit are operatively connected to the corresponding outputs of the second rotator. Responsive to selection of 32-bit rotation mode, the upper half of the inputs to the first rotator are zero and the lower half of the outputs of the third rotator are replicated in the upper half of the outputs of the third rotator.
摘要:
A method and apparatus for implementing dynamic logic with programmable dynamic logic gates acts as a complement to programmable logic arrays (PLAs) used in high-speed microprocessor designs. A matrix of selectable cells provides powerful logic functions such as AND-OR gate capability with a minimum of inputs and transistors. By using programmable logic arrays and programmable dynamic gates, the efficiency of a logic block can be dramatically improved with little added circuit area.
摘要:
A high-speed carry-lookahead binary adder is disclosed. The binary adder includes multiple rows of carry-lookahead circuits, a half-sum module, and a sum/carry module. A first carry-lookahead circuit row includes multiple four-bit group generate circuits and multiple four-bit group propagate circuits. Each of the four-bit group generate circuits produces a generate signal for a corresponding bit location. Each of the four-bit group propagate circuits produces a propagate signal for a corresponding bit location. The half-sum module is utilized to generate a half-sum signal. By utilizing the half-sum signal, the generate signals, and the propagate signals, the sum/carry module generates sum signals and a carry signal.
摘要:
Methods and apparatus are provided for varying one or more of a supply voltage and reference voltage in an integrated circuit, using independent control of a diode voltage in an asymmetrical double-gate device. An integrated circuit is provided that is controlled by one or more of a supply voltage and a reference voltage. The integrated circuit comprises an independently controlled asymmetrical double-gate device to adjust one or more of the supply voltage and the reference voltage. The independent control may comprise, for example, a back gate bias. The independently controlled asymmetrical double-gate device may be employed in a number of applications, including voltage islands, static RAM, and to improve the power and performance of a processing unit.