Merge pull request #1122 from The-OpenROAD-Project-staging/max-cap-slew-margin

Add CAP_MARGIN & SLEW_MARGIN for overfixing in repair_design

Author: maliberty

docs/user/FlowVariables.md

@@ -154,6 +154,8 @@ Note:
 | `DPO_MAX_DISPLACEMENT`               | Specifies how far an instance can be moved when optimizing.                                                                                   |
 | `GPL_TIMING_DRIVEN`                  | Specifies whether the placer should use timing driven placement.                                                                              |
 | `GPL_ROUTABILITY_DRIVEN`             | Specifies whether the placer should use routability driven placement.                                                                         |
+| `CAP_MARGIN`                         | Specifies a capacitance margin when fixing max capacitance violations. This option allow you to overfix.                                      |
+| `SLEW_MARGIN`                        | Specifies a slew margin when fixing max slew violations. This option allow you to overfix.                                                    |
 
 
 ### Clock Tree Synthesis(CTS)

flow/scripts/resize.tcl

@@ -33,7 +33,17 @@ if {![info exists ::env(FOOTPRINT)]} {
 }
 
 puts "Perform buffer insertion..."
-repair_design
+set additional_args ""
+if { [info exists ::env(CAP_MARGIN)] && $::env(CAP_MARGIN) > 0.0} {
+  puts "Cap margin $::env(CAP_MARGIN)"
+  append additional_args " -cap_margin $::env(CAP_MARGIN)"
+}
+if { [info exists ::env(SLEW_MARGIN)] && $::env(SLEW_MARGIN) > 0.0} {
+  puts "Slew margin $::env(SLEW_MARGIN)"
+  append additional_args " -slew_margin $::env(SLEW_MARGIN)"
+}
+
+repair_design {*}$additional_args
 
 if { [info exists env(TIE_SEPARATION)] } {
   set tie_separation $env(TIE_SEPARATION)