Plowing: Interactive Stretching and Compaction in Magic

The Magic layout editor provides a new operation called plowing, for stretching and compacting Manhattan VLSI layouts. Plowing works directly on the mask-level representation of a layout, allowing portions of it to be rearranged while preserving connectivity and layout-rule correctness. The layout and connectivity rules are read from a file, so plowing is technology independent. Plowing is fast enough to be used interactively. This paper presents the plowing operation and the algorithm used to implement it.