This paper proposes a generalized hyperbolic COordinate Rotation Digital Computer (GH CORDIC) to directly compute logarithms and exponentials with an arbitrary fixed base. In a hardware implementation, it is more effi...
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This paper proposes a generalized hyperbolic COordinate Rotation Digital Computer (GH CORDIC) to directly compute logarithms and exponentials with an arbitrary fixed base. In a hardware implementation, it is more efficient than the state of the art which requires both a hyperbolic CORDIC and a constant multiplier. More specifically, we develop the theory of GH CORDIC by adding a new parameter called base to the conventional hyperbolic CORDIC. This new parameter can be used to specify the base with respect to the computation of logarithms and exponentials. As a result, the constant multiplier is no longer needed to convert base [Formula Omitted] (Euler’s number) to other values because the base of GH CORDIC is adjustable. The proposed methodology is first validated using MATLAB with extensive vector matching. Then, example circuits with 16-bit fixed-point data are implemented under the TSMC 40-nm CMOS technology. Hardware experiment shows that at the highest frequency of the state of the art, the proposed methodology saves 27.98% area, 50.69% power consumption, and 6.67% latency when calculating logarithms; it saves 13.09% area, 40.05% power consumption, and 6.67% latency when computing exponentials. Both calculations do not compromise accuracy. Moreover, it can increase 13% maximum frequency and reduce up to 17.65% latency accordingly compared to the state of the art.
We present the concept of logarithmic computation for neural networks. We explore how logarithmic encoding of non-uniformly distributed weights and activations is preferred over linear encoding at resolutions of 4 bit...
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ISBN:
(纸本)9781509041176
We present the concept of logarithmic computation for neural networks. We explore how logarithmic encoding of non-uniformly distributed weights and activations is preferred over linear encoding at resolutions of 4 bits and less. logarithmic encoding enables networks to 1) achieve higher classification accuracies than fixed-point at low resolutions and 2) eliminate bulky digital multipliers. We demonstrate our ideas in the hardware realization, LogNet, an inference engine using only bitshift-add convolutions and weights distributed across the computing fabric. The opportunities from hardware work in synergy with those from the algorithm domain.
We present the concept of logarithmic computation for neural networks. We explore how logarithmic encoding of non-uniformly distributed weights and activations is preferred over linear encoding at resolutions of 4 bit...
详细信息
ISBN:
(纸本)9781509041183
We present the concept of logarithmic computation for neural networks. We explore how logarithmic encoding of non-uniformly distributed weights and activations is preferred over linear encoding at resolutions of 4 bits and less. logarithmic encoding enables networks to 1) achieve higher classification accuracies than fixed-point at low resolutions and 2) eliminate bulky digital multipliers. We demonstrate our ideas in the hardware realization, LogNet, an inference engine using only bitshift-add convolutions and weights distributed across the computing fabric. The opportunities from hardware work in synergy with those from the algorithm domain.
In recent years, Deep Neural Network (DNN)s have become widely spread. Several high-throughput hardware implementations for DNNs have been proposed. One of the key points for hardware implementations of DNNs is to red...
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ISBN:
(纸本)9781538674475
In recent years, Deep Neural Network (DNN)s have become widely spread. Several high-throughput hardware implementations for DNNs have been proposed. One of the key points for hardware implementations of DNNs is to reduce their circuit scale because DNNs require a lot of product-sum operations. Previous papers presented some accelerators using logarithmic quantization to reduce circuit scale by replacing multipliers with shifters. However, most of them are implemented only for inference, and we can find no previous paper using logarithmic quantization for learning. In this paper, a learning accelerator using a logarithmic quantization is proposed. The accelerator uses a stochastic approach for logarithmic quantization. It enables DNNs to learn using logarithmic quantization values. Preliminary evaluation confirmed that DNNs using the proposed method can achieve recognition of MNIST with an accuracy of 97.8%. This evaluation result proves that the proposed method can be used for learning DNNs. The accelerator using the proposed method is implemented on a field-programmable gate array (FPGA) (Xilinx Zynq7020) and synthesized with Xilinx Vivado 2017.1. As a result, it is confirmed to have 2.9 times smaller circuit scale compared with the same FPGA accelerator using 32-bit fixed point number.
In recent years, Deep Neural Network (DNN)s have become widely spread. Several high-throughput hardware implementations for DNNs have been proposed. One of the key points for hardware implementations of DNNs is to red...
详细信息
ISBN:
(纸本)9781538674482;9781538674475
In recent years, Deep Neural Network (DNN)s have become widely spread. Several high-throughput hardware implementations for DNNs have been proposed. One of the key points for hardware implementations of DNNs is to reduce their circuit scale because DNNs require a lot of product-sum operations. Previous papers presented some accelerators using logarithmic quantization to reduce circuit scale by replacing multipliers with shifters. However, most of them are implemented only for inference, and we can find no previous paper using logarithmic quantization for learning. In this paper, a learning accelerator using a logarithmic quantization is proposed. The accelerator uses a stochastic approach for logarithmic quantization. It enables DNNs to learn using logarithmic quantization values. Preliminary evaluation confirmed that DNNs using the proposed method can achieve recognition of MNIST with an accuracy of 97.8%. This evaluation result proves that the proposed method can be used for learning DNNs. The accelerator using the proposed method is implemented on a field-programmable gate array (FPGA) (Xilinx Zynq7020) and synthesized with Xilinx Vivado 2017.1. As a result, it is confirmed to have 2.9 times smaller circuit scale compared with the same FPGA accelerator using 32-bit fixed point number.
We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecu...
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We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analogdigital computational approaches;otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations.
A hardware algorithm is proposed for improving the speed of the linear digit-recurrence logarithmic algorithm. The convergence rate of this logarithmic algorithm is exponential. Furthermore, the size of the lookup tab...
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A hardware algorithm is proposed for improving the speed of the linear digit-recurrence logarithmic algorithm. The convergence rate of this logarithmic algorithm is exponential. Furthermore, the size of the lookup tables used in the algorithm is smaller than the size of the lookup tables used in the digit-recurrence algorithms. When the word length of the operand is less than or equal to 64 bits, the operations involved in each stage of the logarithmic computation only include small table lookup operation, digit-multiplication, and simple square operations. We conclude that the hardware implementation of our proposed algorithm is very efficient.
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