Layer assignment for printed circuit boards and integrated circuits
Article Abstract:
Layer assignment is the problem of assigning layers to the interconnect wires on printed circuit boards and integrated circuits. Two classes of algorithms for assigning layers are constrained layer assignment and unconstrained, also called topological, layer assignment. Constrained layer assignment techniques are characterized by the objective of assigning specific wires to specific layers. Routing of interconnections is given. Unconstrained layer assignment is characterized by the physical routing of both interconnections and the wire layer assignment. While most of the algorithms are presented in two layer processes, multilayer assignment algorithms have also been developed. The algorithms apply to both printed circuit board routing and integrated circuit interconnection routing, but some are directed primarily at very large scale integration chips. There is a great body of literature on layer assignment, and algorithms presented build upon earlier techniques.
Publication Name: Proceedings of the IEEE
Subject: Electronics
ISSN: 0018-9219
Year: 1992
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Software maintenance: the need for standardization
Article Abstract:
A model for the standardization of software maintenance is developed which addresses: metrics, maintenance model, change documentation, software communications processes, and a development methodology that supports maintenance. The ease of change of software often causes maintenance problems, with over 40 percent of the cost of an application involving maintenance operations (enhancement, extension, debugging). Consequently, a standard model of software maintenance would facilitate the management of software change for improved effectiveness and reduced costs. Each of the components of the model are described. A state diagram development methodology provides a case study of the value of software maintenance standards.
Publication Name: Proceedings of the IEEE
Subject: Electronics
ISSN: 0018-9219
Year: 1989
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