new priority onehot module for better area/time

pipelined/src/generic/priorityonehot.sv

@@ -39,9 +39,11 @@ module priorityonehot #(parameter N = 8) (
   input  logic  [N-1:0] a,
   output logic  [N-1:0] y
 );
-  logic [N-1:0] nolower;
 
-  // create thermometer code mask
-  prioritythermometer #(N) maskgen(.a({a[N-2:0], 1'b0}), .y(nolower));
-  assign y = a & nolower;
+  genvar i;
+  assign y[0] = a[0];
+  for (i=1; i<N; i++) begin:poh
+    assign y[i] = a[i] & ~|a[i-1:0];
+  end
+
 endmodule

synthDC/Makefile

@@ -5,8 +5,8 @@ NAME := synth
 
 # defaults
 export DESIGN ?= wallypipelinedcore
-export FREQ ?= 3402
-export CONFIG ?= rv32e
+export FREQ ?= 3000
+export CONFIG ?= rv32gc
 # sky130 and sky90 presently supported
 export TECH ?= tsmc28
 # MAXCORES allows parallel compilation, which is faster but less CPU-efficient
@@ -14,7 +14,7 @@ export TECH ?= tsmc28
 export MAXCORES ?= 4
 # MAXOPT turns on flattening, boundary optimization, and retiming
 # The output netlist is hard to interpret, but significantly better PPA
-export MAXOPT ?= 0
+export MAXOPT ?= 1
 export DRIVE ?= FLOP
 
 time := $(shell date +%F-%H-%M)

synthDC/scripts/synth.tcl

@@ -102,7 +102,8 @@ set_critical_range [expr $my_period*0.05] $current_design
 
 # Partitioning - flatten or hierarchically synthesize
 if { $maxopt == 1 } {
-    ungroup -all -flatten -simple_names
+    ungroup -all -simple_names
+    # -flatten 
 }
 
 # Set input pins except clock