grt: minor fixes on readme

Signed-off-by: Eder Monteiro <[email protected]>

Author: eder-matheus

src/grt/README.md

@@ -43,7 +43,7 @@ global_route
 | `-congestion_report_iter_step` | Set the number of iterations to report. The default value is `0`, and the allowed values are integers `[0, MAX_INT]`. |
 | `-grid_origin` | Set the (x, y) origin of the routing grid in DBU. For example, `-grid_origin {1 1}` corresponds to the die (0, 0) + 1 DBU in each x--, y- direction. |
 | `-critical_nets_percentage` | Set the percentage of nets with the worst slack value that are considered timing critical, having preference over other nets during congestion iterations (e.g. `-critical_nets_percentage 30`). The default value is `0`, and the allowed values are integers `[0, MAX_INT]`. |
-| `-skip_large_fanout_nets` | Skips routing for nets with a fanout higher than the specified limit. Nets exceeding this pin count threshold will be ignored by the global router. The default value is `-1`, and the allowed values are integers `[0, MAX_INT]`. |
+| `-skip_large_fanout_nets` | Skips routing for nets with a fanout higher than the specified limit. Nets above this pin count threshold are ignored by the global router and will not have routing guides, meaning they will also be skipped during detailed routing. This option is useful in debugging or estimation flows where high-fanout nets (such as pre-CTS clock nets) can be ignored. The default value is 0, indicating no fanout limit. The default value is `0`, meaning no limit for net fanout. The allowed values are integers `[0, MAX_INT]`. |
 | `-allow_congestion` | Allow global routing results to be generated with remaining congestion. The default is false. |
 | `-verbose` | This flag enables the full reporting of the global routing. |
 | `-start_incremental` | This flag initializes the GRT listener to get the net modified. The default is false. |

src/grt/include/grt/GlobalRouter.h

@@ -499,7 +499,7 @@ class GlobalRouter
   int total_diodes_count_;
   bool is_congested_{false};
   bool use_cugr_{false};
-  int skip_large_fanout_{-1};
+  int skip_large_fanout_{0};
 
   // Region adjustment variables
   std::vector<RegionAdjustment> region_adjustments_;