add CTS_DELAY_BUFFER_DERATE_PCT

Signed-off-by: Kareem Farid <kareefardi@users.noreply.github.com>
efabless · Dec 15, 2024 · 54c27be · 54c27be
1 parent f7ac225
commit 54c27be
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Showing 4 changed files with 19 additions and 7 deletions.
diff --git a/.Changelog-dev.md b/.Changelog-dev.md
diff --git a/Changelog.md b/Changelog.md
@@ -14,6 +14,15 @@
 ## Documentation
 -->
 
+# Dev
+
+## Steps
+
+* `OpenROAD.CTS`
+  * Added flags `CTS_OBSTRUCTION_AWARE` and `CTS_BALANCE_LEVELS`
+  * Added `CTS_SINK_BUFFER_MAX_CAP_DERATE_PCT`
+  * Added `CTS_DELAY_BUFFER_DERATE_PCT`
+
 # 2.2.9
 
 ## Steps

diff --git a/openlane/scripts/openroad/cts.tcl b/openlane/scripts/openroad/cts.tcl
@@ -59,6 +59,9 @@ if { [info exists ::env(CTS_OBSTRUCTION_AWARE)] && $::env(CTS_OBSTRUCTION_AWARE)
 if { [info exists ::env(CTS_SINK_BUFFER_MAX_CAP_DERATE_PCT)] } {
     lappend arg_list -sink_buffer_max_cap_derate [expr $::env(CTS_SINK_BUFFER_MAX_CAP_DERATE_PCT) / 100.0]
 }
+if { [info exists ::env(CTS_DELAY_BUFFER_DERATE_PCT)] } {
+    lappend arg_list -delay_buffer_derate [expr $::env(CTS_DELAY_BUFFER_DERATE_PCT) / 100]
+}
 if { [info exists ::env(CTS_BALANCE_LEVELS)] && $::env(CTS_BALANCE_LEVELS) } {
     lappend arg_list -balance_levels
 }

diff --git a/openlane/steps/openroad.py b/openlane/steps/openroad.py
@@ -2025,6 +2025,13 @@ class CTS(ResizerStep):
                 + "The value of 100 means no derating of max cap limit",
                 units="%",
             ),
+            Variable(
+                "CTS_DELAY_BUFFER_DERATE_PCT",
+                Optional[Decimal],
+                "This option balances latencies between macro cells and registers by inserting delay buffers"
+                + "The value of 100 means all needed delay buffers are inserted",
+                units="%",
+            ),
             Variable(
                 "CTS_OBSTRUCTION_AWARE",
                 Optional[bool],