# Replace some fillers with decaps to meet density requirements # Set the desired core VDD/VSS decap value for the entire design set core_decap_value_pF 1000 # Capacitance were values obtained in simulation from RC -3dB corner (commands expect fF) set decap_cells [list sky130_fd_sc_hd__decap_12 \ sky130_fd_sc_hd__decap_8 \ sky130_fd_sc_hd__decap_6 \ sky130_fd_sc_hd__decap_4 \ sky130_fd_sc_hd__decap_3 \ ] # these values may not be correct for sky130, but it is okay set decap_values_fF [list 531.681 255.288 128.376 56.747 11.216] # Populate decap candidates foreach capname $decap_cells capvalue $decap_values_fF { addDeCapCellCandidates $capname $capvalue } # Add decap in between filler (requires earlier call to setFillerMode) deleteFiller addDeCap -totCap [expr $core_decap_value_pF * 1000] -cells $decap_cells -prefix DECAP addFiller