Macro/Custom Cell Chip-Planning, Placement, and Global Routing
This chapter presents the algorithms and the implementation of a new macro/custom cell placement and global routing package. This package, named TimberWolfMC, makes extensive use of the simulated annealing algorithm presented in Chapter 2. TimberWolfMC is applicable to circuits containing cells of any rectilinear shape. Furthermore, the cells may have fixed geometry including pin locations (macro cells) or the cells may have an estimated area with a specified aspect ratio range, and with pins that need to be placed (custom cells). The pins for a custom cell may be specified in several possible ways: (1) a pin may be given a particular fixed location, (2) a pin may be assigned to a particular edge or edges of a cell, (3) a pin may belong to a group of pins which may be assigned to a particular edge or edges of a cell, or (4) a pin may belong to a group of pins which is assigned a particular sequential ordering as well as a particular edge or edges of a cell. The placement of a single pin, a group of pins, or a sequence of pins may be specified as being restricted to either one cell edge, two cell edges, or any of the edges.
KeywordsSimulated Annealing Core Area Simulated Annealing Algorithm Cell Placement Cell Edge
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