yosys: remove unused PERIOD_PS variable

Author: phsauter

yosys/scripts/yosys_common.tcl

@@ -13,7 +13,6 @@
 set variables {
     sv_flist    { SV_FLIST    "../croc.flist" }
     top_design  { TOP_DESIGN  "croc_chip"     }
-    period_ps   { PERIOD_PS   10000           }
     out_dir     { OUT         out             }
     tmp_dir     { TMP         tmp             }
     rep_dir     { REPORTS     reports         }
@@ -48,6 +47,7 @@ proc processAbcScript {abc_script} {
     set src_dir [file join [file dirname [info script]] ../src]
     set abc_out_path $tmp_dir/[file tail $abc_script]
 
+    # substitute {STRING} placeholders with their value
     set raw [read -nonewline [open $abc_script r]]
     set abc_script_recaig [string map -nocase [list "{REC_AIG}" [subst "$src_dir/lazy_man_synth_library.aig"]] $raw]
     set abc_out [open $abc_out_path w]

yosys/scripts/yosys_synthesis.tcl

@@ -133,6 +133,7 @@ yosys tee -q -a ${rep_dir}/${top_design}_instances.rpt  select -list "t:tc_clk*$
 yosys dfflibmap {*}$tech_cells_args
 
 # then perform bit-level optimization and mapping on all combinational clouds in ABC
+# target period (per optimized block/module) in picoseconds
 set period_ps 10000
 # pre-process abc file (written to tmp directory)
 set abc_comb_script   [processAbcScript scripts/abc-opt.script]

yosys/yosys.mk

@@ -17,8 +17,6 @@ YOSYS_REPORTS	:= $(YOSYS_DIR)/reports
 
 # top level to be synthesized
 TOP_DESIGN		?= croc_chip
-# target period in picoseconds
-PERIOD_PS		?= 10000
 
 # file containing include dirs, defines and paths to all source files
 SV_FLIST    	:= $(realpath $(YOSYS_DIR)/..)/croc.flist
@@ -38,7 +36,6 @@ $(NETLIST) $(NETLIST_DEBUG):  $(SV_FLIST)
 	cd $(YOSYS_DIR) && \
 	SV_FLIST="$(SV_FLIST)" \
 	TOP_DESIGN="$(TOP_DESIGN)" \
-	PERIOD_PS="$(PERIOD_PS)" \
 	TMP="$(YOSYS_TMP)" \
 	OUT="$(YOSYS_OUT)" \
 	REPORTS="$(YOSYS_REPORTS)" \