Merge pull request #9037 from The-OpenROAD-Project-staging/grt-estimate-resistance

grt: API to estimate path resistance between two pins

Author: maliberty

src/grt/README.md

@@ -359,6 +359,24 @@ read_global_route_segments file_name
 | ----- | ----- |
 | `file_name` | Path to global routing segments file. | 
 
+### Estimate Path Resistance Between Two Pins
+
+This command calculates the path resistance between two pins considering the 
+vias and wires connecting them. The two pins need to be connected by the same
+wire.
+
+```tcl
+estimate_path_resistance pin_name_1 pin_name_2 [-verbose]
+```
+
+#### Options
+
+| Switch Name | Description |
+| ----- | ----- |
+| `pin_name_1` | Pin name 1 (e.g., `_437_/Y`). | 
+| `pin_name_2` | Pin name 1 (e.g., `_438_/A`). |
+| `-verbose` | Print path details. |
+
 ## Example scripts
 
 Examples scripts demonstrating how to run FastRoute on a sample design of `gcd` as follows:

src/grt/include/grt/GlobalRouter.h

@@ -19,6 +19,7 @@
 #include "grt/RoutePt.h"
 #include "odb/db.h"
 #include "odb/dbBlockCallBackObj.h"
+#include "odb/dbObject.h"
 #include "odb/geom.h"
 #include "sta/Liberty.hh"
 
@@ -286,6 +287,19 @@ class GlobalRouter
   void createWLReportFile(const char* file_name, bool verbose);
   std::vector<PinGridLocation> getPinGridPositions(odb::dbNet* db_net);
 
+  // Report wire resistance
+  float getLayerResistance(int layer, int length, odb::dbNet* net);
+  float getViaResistance(int from_layer, int to_layer);
+  double dbuToMicrons(int dbu);
+  float estimatePathResistance(odb::dbObject* pin1,
+                               odb::dbObject* pin2,
+                               bool verbose = false);
+  float estimatePathResistance(odb::dbObject* pin1,
+                               odb::dbObject* pin2,
+                               odb::dbTechLayer* layer1,
+                               odb::dbTechLayer* layer2,
+                               bool verbose = false);
+
   bool findPinAccessPointPositions(
       const Pin& pin,
       std::map<int, std::vector<PointPair>>& ap_positions);