diff --git a/bin/libppa.pl b/bin/libppa.pl
new file mode 100755
index 000000000..56b3702dd
--- /dev/null
+++ b/bin/libppa.pl
@@ -0,0 +1,246 @@
+#!/bin/perl -W
+
+###########################################
+## libppa.pl
+##
+## Written: David_Harris@hmc.edu 
+## Created: 28 January 2023
+##
+## Purpose: Extract PPA information from Liberty files
+##          presently characterizes Skywater 90 and TSMC28hpc+
+##
+## The user will need to change $libpath to point to the desired library in your local installation
+## and for TSMC change the $cellname to the actual name of the inverter.
+##
+## A component of the CORE-V-WALLY configurable RISC-V project.
+##
+## Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
+##
+## SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
+##
+## Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
+## except in compliance with the License, or, at your option, the Apache License version 2.0. You 
+## may obtain a copy of the License at
+##
+## https:##solderpad.org/licenses/SHL-2.1/
+##
+## Unless required by applicable law or agreed to in writing, any work distributed under the 
+## License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
+## either express or implied. See the License for the specific language governing permissions 
+## and limitations under the License.
+################################################################################################
+
+use strict;
+use warnings;
+
+# global variables for simplicity
+my @index1; my @index2;
+my @values;
+my @cr; my @cf; my @rt; my @ft;
+
+# cell and corners to analyze
+my $libpath; my $libbase; my $cellname; my @corners;
+
+# Sky90
+$libpath ="/opt/riscv/cad/lib/sky90/sky90_sc/V1.7.4/lib";
+$libbase = "scc9gena_";
+$cellname = "scc9gena_inv_1";
+@corners = ("tt_1.2v_25C", "tt_1.08v_25C", "tt_1.32v_25C", "tt_1.2v_-40C", "tt_1.2v_85C", "tt_1.2v_125C", "ss_1.2v_25C", "ss_1.08v_-40C", "ss_1.08v_25C", "ss_1.08v_125C", "ff_1.2v_25C", "ff_1.32v_-40C", "ff_1.32v_25C", "ff_1.32v_125C");
+printf("Library $libbase Cell $cellname\n");
+foreach my $corner (@corners) {
+    &analyzeCell($corner);
+}
+
+# TSMC
+$libpath = "/proj/models/tsmc28/libraries/28nmtsmc/tcbn28hpcplusbwp30p140_190a/TSMCHOME/digital/Front_End/timing_power_noise/NLDM/tcbn28hpcplusbwp30p140_180a";
+$libbase = "tcbn28hpcplusbwp30p140";
+$cellname = "INVD1..."; // replace this with the full name of the library cell
+@corners = ("tt0p9v25c", "tt0p8v25c", "tt1v25c", "tt0p9v85c", "ssg0p9vm40c", "ssg0p9v125c", "ssg0p81vm40c", "ssg0p81v125c", "ffg0p88vm40c", "ffg0p88v125c", "ffg0p99vm40c", "ffg0p99v125c");
+printf("\nLibrary $libbase Cell $cellname\n");
+foreach my $corner (@corners) {
+    &analyzeCell($corner);
+}
+
+#############
+# subroutines
+#############
+
+sub analyzeCell {
+    my $corner = shift;
+    my $fname = $libpath."/".$libbase.$corner.".lib";
+    open (FILE, $fname) || die("Can't read $fname");
+    my $incell = 0;
+    my $inleakage = 0;
+    my $inpin = 0;
+    my $incellrise = 0;
+    my $incellfall = 0;
+    my $inrisetrans = 0;
+    my $infalltrans = 0;
+    my $inindex = 0;
+    my $invalues = 0;
+    my $searchstring = "cell (".$cellname.")";
+    my $area; my $leakage; my $cap;
+     while (<FILE>) {
+	if (index($_, $searchstring) != -1) { $incell = 1;}
+	elsif ($incell) {
+	    if (/cell \(/) {
+		$incell = 0;
+		close(FILE);
+		last;
+	    }
+	    if (/area\s*:\s*(.*);/) { $area = $1; }
+	    if (/cell_leakage_power\s*:\s*(.*);/) { $leakage = $1; $inleakage = 2; }
+	    if ($inleakage == 0 && /leakage_power/) { $inleakage = 1; }
+	    if ($inleakage == 1 && /value\s*:\s*(.*);/) {
+		$leakage = $1;
+		$inleakage = 2;
+	    }
+	    if ($inpin == 0 && /pin/) { $inpin = 1; }
+	    if ($inpin == 1 && /\s+capacitance\s*:\s*(.*);/) {
+		$cap = $1;
+		$inpin = 2;
+	    }
+	    if ($inindex == 0 && /index_1/) { $inindex = 1; }
+	    if ($inindex == 1) {
+		if (/index_1\s*\(\"(.*)\"\);/) { @index1 = split(/, /, $1); }
+		if (/index_2\s*\(\"(.*)\"\);/) { @index2 = split(/, /, $1); $inindex = 2; }
+	    }
+	    if ($incellrise == 0 && /cell_rise/) { $incellrise = 1; $invalues = 0;}
+	    if ($incellfall == 0 && /cell_fall/) { $incellfall = 1; $invalues = 0; }
+	    if ($inrisetrans == 0 && /rise_trans/) { $inrisetrans = 1; $invalues = 0; }
+	    if ($infalltrans == 0 && /fall_trans/) { $infalltrans = 1; $invalues = 0; }
+	    if ($incellrise == 1 || $incellfall == 1 || $inrisetrans == 1 || $infalltrans == 1) {
+		if (/values/) { $invalues = 1; @values = (); }
+		elsif ($invalues == 1) {
+		    if (/\);/) {
+			$invalues = 2;
+			if ($incellrise == 1) { @cr = &parseVals(); $incellrise = 2; }
+			if ($incellfall == 1) { @cf = &parseVals(); $incellfall = 2; }
+			if ($inrisetrans == 1) { @rt = &parseVals(); $inrisetrans = 2; }
+			if ($infalltrans == 1) { @ft = &parseVals(); $infalltrans = 2; }
+		    }
+		    elsif (/\"(.*)\"/) { push(@values, $1); }
+		}
+	    }
+#	    print $_;
+	}
+    }
+    
+    my $delay = &computeDelay($cap);
+    my $cornerr = sprintf("%20s", $corner);
+    my $delayr = sprintf("%2.1f", $delay*1000);
+    my $leakager = sprintf("%3.1f", $leakage);
+    
+    print("$cornerr: Delay $delayr Leakage: $leakager capacitance: $cap\n");
+    #print("$cellname $corner: Area $area Leakage: $leakage capacitance: $cap delay $delay\n");
+    #print(" index1: @index1\n");
+    #print(" index2: @index2\n");
+    #print("Cell Rise\n"); printMatrix(\@cr);
+    #print("Cell Fall\n"); printMatrix(\@cf);
+    #print("Rise Trans\n"); printMatrix(\@rt);
+    #print("Fall Trans\n"); printMatrix(\@ft);
+}
+
+sub computeDelay {
+    # relies on cr, cf, rt, ft, index1, index2
+    # index1 for rows of matrix (different trans times, units of ns)
+    # index2 for cols of matrix (different load capacitances, units of pF)
+
+    # first, given true load, create a rise/fall delay and transition
+    # as a function of trans time, interpolated
+    my $cap = shift;
+    my $fo4cap = 4*$cap;
+    my @cri = &interp2(\@cr, $fo4cap);
+    my @cfi = &interp2(\@cf, $fo4cap);
+    my @rti = &interp2(\@rt, $fo4cap);
+    my @fti = &interp2(\@ft, $fo4cap);
+
+    # initially guess second smallest transition time
+    my $tt = $index1[1];
+    # assume falling input with this transition, compute rise delay & trans
+    my $cr0 = &interp1(\@cri, \@index1, $tt);
+    my $rt0 = &interp1(\@rti, \@index1, $tt);
+    # now assuming rising input with rt0, compute fall delay & trans
+    my $cf1 = &interp1(\@cfi, \@index1, $rt0);
+    my $ft1 = &interp1(\@fti, \@index1, $rt0);
+    # now assuming falling input with ft1, compute rise delay & trans
+    my $cr2 = &interp1(\@cri, \@index1, $ft1);
+    my $rt2 = &interp1(\@rti, \@index1, $ft1);
+    # now assuming rising input with rt2, compute fall delay & trans
+    my $cf3 = &interp1(\@cfi, \@index1, $rt2);
+    my $ft3 = &interp1(\@fti, \@index1, $rt2);
+
+    # delay is average of rising and falling
+    my $delay = ($cr2 + $cf3)/2;
+    return $delay;
+    
+#    print("tt $tt cr0 $cr0 rt0 $rt0\n");
+#    print("cf1 $cf1 ft1 $ft1 cr2 $cr2 rt2 $rt2 cf3 $cf3 ft3 $ft3 delay $delay\n");
+}
+
+sub interp2 {
+    my $matref = shift;
+    my @matrix = @$matref;
+    my $fo4cap = shift;
+    my @interp = ();
+    
+    my $i;
+    # interpolate row by row
+    for ($i=0; $i <= $#index1; $i++) {
+	my @row = @{$matrix[$i]};
+	#print ("Extracted row $i = @row\n");
+	$interp[$i] = &interp1(\@row, \@index2, $fo4cap);
+    }
+    return @interp;
+}
+
+sub interp1 {
+    my $vecref = shift;
+    my @vec = @$vecref;
+    my $indexref = shift;
+    my @index = @$indexref;
+    my $x = shift;
+
+    # find entry i containing the first index greater than x
+    my $i = 0;
+    while ($index[$i] < $x) {$i++}
+    my $start = $index[$i-1];
+    my $end = $index[$i];
+    my $fract = ($x-$start)/($end-$start);
+    my $interp = $vec[$i-1] + ($vec[$i] - $vec[$i-1])*$fract;
+
+#    print ("Interpolating $x as $interp from i $i start $start end $end based on index @index and vec @vec\n");
+
+    return $interp;
+}
+
+sub parseVals {
+    # relies on global variables @values, @index1, @index2
+    my @vals;
+    my $i; my $j;
+    for ($i=0; $i <= $#index1; $i++) {
+	my @row = split(/, /,$values[$i]);
+	for ($j = 0; $j <= $#index2; $j++) {
+	    $vals[$i][$j] = $row[$j];
+	}
+    }
+    return @vals;
+}
+
+sub printMatrix {
+    my $mat = shift;
+    my @matrix = @$mat;
+    my $i; my $j;
+    for ($i=0; $i <= $#index1; $i++) {
+	for ($j = 0; $j <= $#index2; $j++) {
+	    print($matrix[$i][$j]." ");
+	}
+	print("\n");
+    }
+}
+
+    
+    
+
+
+