make -mask_size optional, default to using word_size if not specified

Signed-off-by: Thinh Nguyen <nguyenthinh19011@gmail.com>

Author: tnguy19

src/ram/src/ram.tcl

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright (c) 2024-2025, The OpenROAD Authors
 
-sta::define_cmd_args "generate_ram_netlist" {-mask_size bits
+sta::define_cmd_args "generate_ram_netlist" {[-mask_size bits]
                                              -word_size bits
                                              -num_words words
                                              [-column_mux_ratio ratio]
@@ -22,18 +22,18 @@ proc generate_ram_netlist { args } {
     set column_mux_ratio $keys(-column_mux_ratio)
   }
 
-  if { [info exists keys(-mask_size)] } {
-    set mask_size $keys(-mask_size)
-  } else {
-    utl::error RAM 1 "The -mask_size argument must be specified."
-  }
-
   if { [info exists keys(-word_size)] } {
     set word_size $keys(-word_size)
   } else {
     utl::error RAM 2 "The -word_size argument must be specified."
   }
 
+  if { [info exists keys(-mask_size)] } {
+    set mask_size $keys(-mask_size)
+  } else {
+    set mask_size $word_size
+  }
+
   if { $word_size % $mask_size != 0 } {
     utl::error RAM 26 "The -word_size ($word_size) must be divisible by -mask_size ($mask_size)."
   }
@@ -87,7 +87,7 @@ proc generate_ram_netlist { args } {
     $tristate_cell $inv_cell $read_ports $tapcell $max_tap_dist
 }
 
-sta::define_cmd_args "generate_ram" {-mask_size bits
+sta::define_cmd_args "generate_ram" {[-mask_size bits]
                                      -word_size bits
                                      -num_words words
                                      [-column_mux_ratio ratio]
@@ -122,10 +122,13 @@ proc generate_ram { args } {
   }
 
   set ram_netlist_args [list \
-    -mask_size $keys(-mask_size) \
     -word_size $keys(-word_size) \
     -num_words $keys(-num_words)]
 
+  if { [info exists keys(-mask_size)] } {
+    lappend ram_netlist_args -mask_size $keys(-mask_size)
+  }
+
   if { [info exists keys(-read_ports)] } {
     lappend ram_netlist_args -read_ports $keys(-read_ports)
   }