Modern floorplanning with abutment and fixed-outline constraints

Typical floorplanning problem concerns a series of objectives, such as area, wirelength and routability, etc., without any specific constraint in a free-outline style. Entering SOC era, however, modem floorplanning takes more care of providing extra options to place dedicated modules in the hierarchical designs, such as abutment, boundary and fixed-outline constraints, etc. It has been empirically shown that any of the modem constraints extremely restricts the solution space, that is, a large number of randomly generated floorplans might violate the constraint. This paper addresses modem floorplanning with abutment and fixed-outline constraints. In order to search the drastically limited solution space, we first investigate the feasible properties of a slicing floorplan with abutment constraint. The properties, coupled with an efficient evolutionary search algorithm, provide the way to produce floorplans with abutment constraint. We then extend the algorithm with minor modification to enable the abutment floorplans to be gradually fit into the desirable fixed outline. The methods are verified by using the MCNC and GSRC benchmarks, and the empirical results show that our methods can obtain promising solutions using short time.