Fremont, Calif.--Sept. 25, 1997--Avanti Corp. (Fremont) introduced a new transmission line element (W-element) and simulation support for transmission lines within the latest release of Star-Hspice, 1997.2. The new W-element offers advanced modeling for transmission lines and Star-Hspice offers simulation support. The unique ability of W-element to accurately model frequency dependent loss in the time domain is crucial for simulation of high-speed designs, communication networks, instrumentation cables, and for modeling of silicon slow-wave effect in deep-submicron interconnects.
Benchmarks indicate that the method is 600 times faster than the Spice convolution model and thousands of times faster than the U-element.
Switching speeds of high-speed circuits and the dominance of interconnect parasitics causes a significant need for transient analysis of transmission lines. Accounting for these effects requires an accurate and efficient multi-conductor lossy frequency-dependent transmission line element and supporting algorithms for analysis. Inaccurate analysis can result in non-functional ICs or boards, unnecessary redesign spins, under-performing silicon due to conservative estimation, and consequently missed time to market windows.
The newly added transmission line analysis is based on a novel, efficient simulation method. Both AC and DC analysis employ exact analytical solutions. Transient analysis is based on open-loop transmission line characterization, frequency-domain difference approximation, and indirect numerical integration. This enables accurate modeling of the frequency-dependent loss in the time domain. The technique does not introduce internal nodes or current variables, and avoids computationally expensive convolution. The simulation performance is almost equivalent to the speed of simulating a single resistor.
The W-element takes frequency-dependent RLGC (resistance, inductance, conductance, and capacitance) matrices as input, like those produced by field solvers. There are no restrictions on the matrix structure or number of coupled conductors. 128- or 256-conductor busses can be simulated without neglecting any coupling between the conductors. The W-element requires no manual adjustments, and produces accurate results with large time steps. The accuracy and efficiency of W-element do not depend on the line length, amount of loss, coupling, or frequency. This allows users to efficiently simulate hundred- or thousand-meter-long communication cables.
The W-element and supporting algorithms are available now within the 1997.2 release of Star-Hspice. Existing Star-Hspice users with maintenance will receive the W-element capability as part of their normal product updates.
Fax: (510) 413-8080
Return to Headlines