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Showing 3 results for Abolmaali
Efficient Delay Characterization Method to Obtain the Output Waveform of Logic Gates Considering Glitches
S. Abolmaali,
Volume 15, Issue 4 (December 2019)
Abstract
Accurate delay calculation of circuit gates is very important in timing analysis of digital circuits. Waveform shapes on the input ports of logic gates should be considered, in the characterization phase of delay calculation, to obtain accurate gate delay values. Glitches and their temporal effect on circuit gate delays should be taken into account for this purpose. However, the explosive number of combinations of waveform shapes, which can be applied to the input ports of logic gates, causes existing lookup-based methods to have huge space requirements. In this article, instead of considering all possible combinations of waveform shapes in the characterization phase of delay calculation process, the least number of combinations, which are dominant in determining the waveform shape of gate output, is presented. Multivariate Polynomial Regression (MPR) method is used to further reduce the required memory space. Exploration of the possible MPR analyses is performed to find the best regression case with proper memory space reduction and precision. Attained results show a 1.013E6 times reduction in storage space required for storing parameters utilized in extraction of output waveform characteristics in comparison to a state of the artwork, accompanied by acceptable precision.

Area Reduction of Combinational Circuits Considering Path Sensitization
S. Abolmaali,
Volume 17, Issue 3 (September 2021)
Abstract
Area reduction of a circuit is a promising solution for decreasing the power consumption and the chip cost. Timing constraints should be preserved after a delay increase of resized circuit gates to guarantee proper circuit operation. Sensitization of paths should also be considered in timing analysis of circuit to prevent pessimistic resizing of circuit gates. In this work, a greedy area reduction algorithm is proposed which is path-based and benefits well from viability analysis as the sensitization method. A proper metric based on viability conditions is presented to guide the algorithm towards selecting useful circuit nodes to be resized with acceptable performance and area reduction results. Instead of using gate slacks in resizing the candidate gates, all circuit gates are down-sized first and then the sizes of circuit gates that violate the circuit timing constraint are increased. This approach leads to considerable improvement in the complexity and performance of the proposed method. Results show that area improvement of about 88% is achievable. Comparison to a pessimistic method also reveals that on average 14.2% growth in area improvement is obtained by the presented method.

Static Timing Analysis for Critical Path Identification in Ternary Logic Circuits
S. Abolmaali,
Volume 18, Issue 2 (June 2022)
Abstract
In this article, a critical path identification method is proposed for ternary logic circuits. The considered structure for the ternary circuits is based on 2:1 multiplexers. Sensitization conditions for the employed ternary multiplexers are introduced. Moreover, static timing analysis and dynamic programming are utilized in the identification of true and false paths of the circuit for obtaining more realistic results in a reasonable time. An event-driven simulation engine is also developed for confirming the sensitization state of the identified paths. Some ternary arithmetic logic circuits are designed to depict the effectiveness of the proposed identification method. Simulation results show the correctness and efficiency of the proposed method.

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© 2022 by the authors. Licensee IUST, Tehran, Iran. This is an open access journal distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license.