floorplan: mutually exclusive floorplan methods, pick one

Signed-off-by: Øyvind Harboe <[email protected]>

Author: oharboe

docs/user/FlowVariables.md

@@ -274,6 +274,8 @@ configuration file.
 | `MACRO_HALO_X`         | Set macro halo for x-direction. Only available for ASAP7 PDK. |
 | `MACRO_HALO_Y`         | Set macro halo for y-direction. Only available for ASAP7 PDK. |
 
+The various methods to specify the die and core area(`FLOORPLAN_DEF`, `FOOTPRINT`, `DIE_AREA`, `CORE_AREA` and `CORE_UTILIZATION`) are mutually exclusive. If two methods are specified, floorplan.tcl will exit with an error requiring that a single method is used.
+
 #### Placement
 
 

flow/scripts/floorplan.tcl

@@ -55,7 +55,7 @@ set use_core_utilization [env_var_exists_and_non_empty CORE_UTILIZATION]
 
 set methods_defined [expr {$use_floorplan_def + $use_footprint + $use_die_and_core_area + $use_core_utilization}]
 if {$methods_defined > 1} {
-    puts "ERROR: More than one floorplan initialization method specified"
+    puts "ERROR: Floorplan initialization methods are mutually exclusive, pick one."
     exit 1
 }