Fine Control of Local Whitespace in Placement

Table 1

Real location of whitespace in mPL6 [23] placements of selected ISPD 2006 contest benchmarks [12]. Local whitespace targets are the same as from the ISPD 2006 placement contest. Density violations are measured as the percentage of total cell area that violates density constraints. Using Capo 10.5 in ECO-system mode [13] in combination with our whitespace allocation techniques, we are able to significantly reduce the density violations of the mPL6 placements.

Benchmark	Local WS target	HPWL (e6)		Density violation
		Before	After	Before	After
newblue1	20%	66.61	74.37	1.039%	0.065%
newblue2	10%	199.05	223.87	3.701%	0.964%
newblue3	20%	283.40	297.97	2.813%	0.126%
newblue4	50%	293.22	304.99	7.238%	4.105%