A Diagnostic System Using Boolean Reasoning
Abstract
The goal of this thesis is to design and implement a computer aided diagnostic system for combinational circuits, a type of circuit used in the design of all computers. The diagnostic system is to accept a description of the circuit, supervise an adaptive input-output experiment on a potentially faulty implementation of the circuit, and return the locations of all faults in the circuit. The description of the circuit which will be input to this system can be in one of two forms: Boolean equations, or statements in the VHSIC Hardware Description Language (VHDL). Based on the circuit structure, a fault model is developed which can be used to mathematically model the state of faults in the circuit. The circuit description is processed to derive a single Boolean characteristic equation; information gained from testing is used to update this equation. The characteristic equation is manipulated to generate test vectors which are used as inputs to the actual circuit being diagnosed. After a given test vector has been input to the circuit, the output is observed. The state of the circuit output is then input to the diagnostic system which uses it to derive new knowledge about the actual circuit. Such tests are conducted repetively until the diagnostic system determines that further information cannot be derived from testing. At this point, the diagnostic system determines the nature and location of faults in the actual circuit as well as the function actually performed by the circuit.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1988
- Accession Number
- ADA202764
Entities
People
- James J. Kainec
Organizations
- Air Force Institute of Technology