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author | Jordan K. Hubbard <jkh@FreeBSD.org> | 1995-01-03 09:12:58 +0000 |
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committer | Jordan K. Hubbard <jkh@FreeBSD.org> | 1995-01-03 09:12:58 +0000 |
commit | 24951e980cbe94cde7da06a4c437c51afbf9803e (patch) | |
tree | 7ba311b1e0896e77c9b59f9e1626739d59693f45 /cad/acs/pkg-descr | |
parent | Mahjongg (diff) |
acs (Al's Circuit Simulator) from Thomas Gellekum <thomas@ghpc8.ihf.rwth-aachen.de>
Submitted by: thomas
Notes
Notes:
svn path=/head/; revision=672
Diffstat (limited to 'cad/acs/pkg-descr')
-rw-r--r-- | cad/acs/pkg-descr | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/cad/acs/pkg-descr b/cad/acs/pkg-descr new file mode 100644 index 000000000000..efc0bfdaf161 --- /dev/null +++ b/cad/acs/pkg-descr @@ -0,0 +1,48 @@ +ACS is a general purpose circuit simulator. It performs nonlinear +dc and transient analyses, fourier analysis, and ac analysis +linearized at an operating point. It is fully interactive and +command driven. It can also be run in batch mode or as a server. +The output is produced as it simulates. Spice compatible models +for the MOSFET (level 1 and 2) and diode are included in this +release. + +Since it is fully interactive, it is possible to make changes and +re-simulate quickly. The interactive design makes it well suited +to the typical iterative design process used it optimizing a circuit +design. It is also well suited to undergraduate teaching where +Spice in batch mode can be quite intimidating. This version, while +still officially in beta test, should be stable enough for basic +undergraduate teaching and courses in MOS design, but not for +bipolar design. + +In batch mode it is mostly Spice compatible, so it is often possible +to use the same file for both ACS and Spice. + +The analog simulation is based on traditional nodal analysis with +iteration by Newton's method and LU decomposition. An event queue +and incremental matrix update speed up the solution for large +circuits. + +It also has digital devices for mixed signal simulation. The +digital devices may be implemented as either analog subcircuits or +as true digital models. The simulator will automatically determine +which to use. Networks of digital devices are simulated as digital, +with no conversions to analog between gates. This results in +digital circuits being simulated faster than on a typical analog +simulator, even with behavioral models. The digital mode is +experimental and needs work. There will be substantial improvements +in future releases. + +ACS also has a simple behavioral modeling language that allows +simple behavioral descriptions of most components including capacitors +and inductors. Unfortunately, it is not well documented. + +ACS uses an object oriented approach to modeling. Complex models +like MOSFETS are made of simpler ones like resistors, capacitors, +diodes, and any other models that may already exist. The model +designer does not need to worry about details like convergence +checking, bypass checking, integration, or how the new device plugs +into the solution matrix because these are already taken care of +by the basic models. This results in a dramatic improvement in +the time it takes a researcher or model designer to install a new +model, compared to Spice. |