Fplan layout

1. block Area estimation

block Area estimation formula ：
Size = stand cell area /0.65 + macro area /0.82

0.65 and 0.82 It's just an experience , According to the actual situation and the metal layer used in the design 、 Dynamic adjustment of process characteristics , However, the utilization ratio of modules can only achieve an average of 65% about . Because we have to consider that maybe some... Will be inserted in the optimization process buffer, If the preset is too high , Maybe later cell density It will be too high to prevent wiring difficulties , Too low is a waste of space , And yes macro Generally speaking, the utilization rate can be as high as 82% about , Because only in macro Mark around 2um Left and right hard blockage.
Area Utilization Generally in 50%~75% Between , This parameter can be determined according to the performance parameters of the specific design .

 ## ICC2：
 ## area
set stdcell_areas 0
set cells [get_cells -q