Circuit Simulation for Mixed-Signal Analog/Digital Circuits

Premal Buch

EECS Department
University of California, Berkeley
Technical Report No. UCB/ERL M95/78
May 1995

http://www2.eecs.berkeley.edu/Pubs/TechRpts/1995/ERL-95-78.pdf

The increasing use of mixed signal circuits with analog and digital circuitry on the same chip have created a set of demands that traditional circuit simulators cannot meet very well. We present techniques to efficiently handle the simulation of mixed signal analog/digital circuits, and SYMPHONY, a fast mixed-signal simulator which embodies them.

SYMPHONY combines a fast simulator for digital circuits with a traditional nonlinear solver a la SPICE for the analog subcircuits. The digital simulator uses Stepwise Equivalence Conductance to model nonlinear device conductances and Piecewise Linear voltage waveforms. Device characteristics of bipolar elements in digital subcircuits are modeled by a Piecewise Linear approximation using the Extended Chebyshev Points, such that the worst case approximation error is minimized. Dynamic circuit partitioning is used to fully exploit the latency and multirate behavior of the circuit. The simulator is implemented in an event-driven framework with local and global clocks for even management. A set of benchmark results are presented on a suit of BiMOS circuits,

A transistor level power estimator which exploits algorithms for fast circuit simulation to compute the power dissipation of CMOS circuits is also presented. The proposed approach uses stepwise equivalent conductance and piecewise linear waveform approximation. The power estimator has been implemented in the SWEC framework. Experimental results indicate that SWEC can obtain a substantial speed-up over HSPICE (and handle circuits that HSPICE cannot) while maintaining an accuracy of within 5-7%. Benchmark results on a suite of industry circuits are presented.

BibTeX citation:

@techreport{Buch:M95/78,
    Author = {Buch, Premal},
    Title = {Circuit Simulation for Mixed-Signal Analog/Digital Circuits},
    Institution = {EECS Department, University of California, Berkeley},
    Year = {1995},
    Month = {May},
    URL = {http://www2.eecs.berkeley.edu/Pubs/TechRpts/1995/2869.html},
    Number = {UCB/ERL M95/78},
    Abstract = {The increasing use of mixed signal circuits with analog and digital
circuitry on the same chip have created a set of demands that
traditional circuit simulators cannot meet very well. We present
techniques to efficiently handle the simulation of mixed signal
analog/digital circuits, and SYMPHONY, a fast mixed-signal
simulator which embodies them.

SYMPHONY combines a fast simulator for digital circuits with
a traditional nonlinear solver a la SPICE for the analog
subcircuits. The digital simulator uses Stepwise Equivalence
Conductance to model nonlinear device conductances and Piecewise
Linear voltage waveforms. Device characteristics of bipolar
elements in digital subcircuits are modeled by a Piecewise Linear
approximation using the Extended Chebyshev Points, such that the
worst case approximation error is minimized.  Dynamic circuit
partitioning is used to fully exploit the latency and multirate
behavior of the circuit. The simulator is implemented in an
event-driven framework with local and global clocks for even
management. A set of benchmark results are presented on a suit of
BiMOS circuits,

A transistor level power estimator which exploits algorithms for fast
circuit simulation to compute the power dissipation of CMOS circuits
is also presented. The proposed approach uses stepwise equivalent
conductance and piecewise linear waveform approximation. The power
estimator has been implemented in the SWEC framework. Experimental
results indicate that SWEC can obtain a substantial speed-up over
HSPICE (and handle circuits that HSPICE cannot) while maintaining
an accuracy of within 5-7%. Benchmark results on a suite of industry
circuits are presented.}
}

EndNote citation:

%0 Report
%A Buch, Premal
%T Circuit Simulation for Mixed-Signal Analog/Digital Circuits
%I EECS Department, University of California, Berkeley
%D 1995
%@ UCB/ERL M95/78
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/1995/2869.html
%F Buch:M95/78