docs: vpr: add description of --write_timing_summary and --write_block_usage

Signed-off-by: Pawel Czarnecki <[email protected]>

Author: lpawelcz

doc/src/vpr/command_line_usage.rst

@@ -626,6 +626,12 @@ For people not working on CAD, you can probably leave all the options to their d
 
     **Default:** ``2``
 
+.. option:: --write_block_usage <file>
+
+    Writes out the block usage summary in machine readable format
+    (JSON or XML, format is selected based on the extension of <file>)
+    to file under path <file>.
+
 .. _placer_options:
 
 Placer Options
@@ -1035,6 +1041,17 @@ VPR uses a negotiated congestion algorithm (based on Pathfinder) to perform rout
 
     **Default:** ``off``
 
+.. option:: --write_timing_summary <file>
+
+    Writes out the final timing summary in machine readable format
+    (JSON or XML, format is selected based on the extension of <file>)
+    to file under path <file>. The summary consists of parameters:
+
+    * `cpd` - Final critical path delay (least slack) [ns]
+    * `fmax` - Maximal frequency of the implemented circuit [MHz]
+    * `swns` - setup Worst Negative Slack (sWNS) [ns]
+    * `stns` - Setup Total Negative Slack (sTNS) [ns]
+
 .. _timing_driven_router_options:
 
 Timing-Driven Router Options