ASTAP (Advanced Statistical Analysis Program) was a general purpose analog electronic circuit

simulator A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the ...

developed primarily for in-house use by IBM from 1973 on. It was a powerful program used for simulation of integrated circuit designs, and their analysis with statistical variations of the manufacturing process. In combination with the built-in

Monte Carlo method Monte Carlo methods, or Monte Carlo experiments, are a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be deter ...

capabilities it allowed prediction of the performance of electronic circuits under a wide range of material parameters and temperatures. ASTAP was designed to run on IBM

Mainframe computer A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterpris ...

s. Its

algorithm In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing ...

s were developed by IBM

electrical engineer Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the ...

s, especially

Robert Brayton The ESPRESSO logic minimizer is a computer program using heuristic and specific algorithms for efficiently reducing the complexity of digital logic gate circuits. ESPRESSO-I was originally developed at IBM by Robert K. Brayton et al. in 1982. an ...

Gary Hachtel Gary may refer to: *Gary (given name), a common masculine given name, including a list of people and fictional characters with the name *Gary, Indiana, the largest city named Gary Places ;Iran *Gary, Iran, Sistan and Baluchestan Province ;Unit ...

, and

Fred Gustavson Fred may refer to: People * Fred (name), including a list of people and characters with the name Mononym * Fred (cartoonist) (1931–2013), pen name of Fred Othon Aristidès, French * Fred (footballer, born 1949) (1949–2022), Frederico Rodr ...

. Unlike

SPICE A spice is a seed, fruit, root, bark, or other plant substance primarily used for flavoring or coloring food. Spices are distinguished from herbs, which are the leaves, flowers, or stems of plants used for flavoring or as a garnish. Spices a ...

, which used

Modified nodal analysis In electrical engineering, modified nodal analysis or MNA is an extension of nodal analysis which not only determines the circuit's node voltages (as in classical nodal analysis), but also ''some'' branch currents. Modified nodal analysis was deve ...

(MNA) to form the system of circuit equations, ASTAP instead used ''sparse tableau approach'' (STA) to construct and solve a

sparse matrix In numerical analysis and scientific computing, a sparse matrix or sparse array is a matrix in which most of the elements are zero. There is no strict definition regarding the proportion of zero-value elements for a matrix to qualify as sparse b ...

. The sparse tableau formulation produced very large, very sparse matrices which required special techniques to solve efficiently, even at that time. The advantage of STA for statistical analysis is that, as originally outlined, a subsequent analysis of a circuit with randomly varied parameters only required changing entries in the matrix.

References

Simulation programming languages Electronic circuit simulators {{simulation-software-stub