# Accession Number:

## ADA136116

# Title:

## Simulation Tools for Digital LSI (Large Scale Integration) Design.

# Descriptive Note:

## Doctoral thesis,

# Corporate Author:

## MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR COMPUTER SCIENCE

# Personal Author(s):

# Report Date:

## 1983-09-01

# Pagination or Media Count:

## 160.0

# Abstract:

This thesis proposes a timing simulator RSIM based on a uniquely simple transistor model. RSIM allows a designer to determine both the functional and approximate timing characteristics of a MOS network with more accuracy than gate-level simulation, and using larger circuits than are accommodated by circuit analysis programs. In RSIM, transistors are modeled as resistors the logic states of a transistors terminal modes determine its effective resistance. Using this model, a MOS network is simulated as a network of resistors where each nodes value is determined by the resistance of its connections to various inputs. Transition times are determined from the RC time constant calculated for the node by examining the surrounding network R from the transistors, C from the interconnect and gate capacitance. The networks behavior as inputs are given values is calculated by an efficient event-driven algorithm. Two changes to the underlying model are also investigated 1 further simplifying the transistor model to an onoff switch which can be thought of as a degenerate resistor. Several approaches to switch-level simulation are developed, one particularly well-suited for implementation using parallel hardware and 2 modeling the behavior of a network of switches by a system of logic equations. Various compilation strategies are evaluated for producing code that implements the system of equations. Author

# Descriptors:

- *Computer aided design
- *Integrated circuits
- *Digital systems
- Circuit analysis
- *Electrical resistance
- *Simulation
- Resistors
- Networks
- Capacitance
- Switches
- Gates(Circuits)
- Transistors
- Parallel orientation
- Systems analysis
- Models
- Value
- Behavior
- Simulators
- Tools
- Nodes
- Equations
- Constants
- Time
- Accuracy
- Theses

# Subject Categories:

- Electrical and Electronic Equipment
- Computer Systems