Title :
Statistical estimation of combinational and sequential CMOS digital circuit activity considering uncertainty of gate delays
Author :
Chou, Tan-Li ; Roy, Kaushik
Author_Institution :
Sch. of Electr. & Comput. Eng., Purdue Univ., West Lafayette, IN, USA
Abstract :
While estimating glitches or spurious transitions is challenging due to signal correlations, the random behavior of logic gate delays makes the estimation problem even more difficult. In this paper, we present statistical estimation of signal activity at the internal and output nodes of combinational and sequential CMOS logic circuits considering uncertainty of gate delays. The methodology is based on the stochastic models of logic signals and the probabilistic behavior of gate delays due to process variations, interconnect parasitics, etc. We propose a statistical technique of estimating average-case activity, which is flexible in adopting different delay models and variations. Experimental results show that the uncertainty of gate delays makes a great impact on activity at individual nodes (more than 100%) and total power dissipation (can be overestimated up to 65%) as well
Keywords :
CMOS logic circuits; circuit analysis computing; combinational circuits; delays; digital simulation; logic CAD; probability; sequential circuits; statistical analysis; stochastic processes; combinational CMOS digital circuit activity; gate delay uncertainty; glitches; interconnect parasitics; logic gate delays; probabilistic behavior; process variations; sequential CMOS digital circuit activity; signal correlations; spurious transitions; statistical estimation; stochastic models; total power dissipation; CMOS logic circuits; Delay estimation; Integrated circuit interconnections; Logic gates; Power dissipation; Probabilistic logic; Semiconductor device modeling; Signal processing; Stochastic processes; Uncertainty;
Conference_Titel :
Design Automation Conference, 1997. Proceedings of the ASP-DAC '97 Asia and South Pacific
Conference_Location :
Chiba
Print_ISBN :
0-7803-3662-3
DOI :
10.1109/ASPDAC.1997.600066