use strict;
use warnings;
use 5.012;
use Data::Dumper;

my $s1 = '45 20 00 00 00 03 00';
my $s2 = '40 20 00 00 00 00 00';

while ((my @a = $s1 =~ /(\d{2})/g) && (my @b = $s2 =~ /(\d{2})/g)){
    say "found $a[0] and $b[0] !!!";
    say Dumper(\@a, \@b);
}