Adds script to replaces some fillers with decaps

GcdUnit/design/cadence-innovus-signoff/configure.yml

@@ -61,6 +61,7 @@ commands:
 
 parameters:
   order:
+    - fill-decap.tcl
     - main.tcl
     - generate-results.tcl
     - reporting.tcl

GcdUnit/design/cadence-innovus-signoff/scripts/fill-decap.tcl

+# 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
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