sub trace_sig_down_hier {

  my $vdb=shift;
  my $module=shift;
  my $signal=shift;
  my $instance=shift;
  my $level=shift;

  print "DEBUG: $module:$module:$signal:$instance:$level\n";
  my($imod,$iname,$port,$l,@connections);


  SIG:foreach my $sig (sort &rvp::get_modules_signals($vdb,$module)) {
	next SIG if ($sig ne $signal);
	
	for (($imod,$iname,$port,$l) = 
	     &rvp::get_first_signal_port_con($vdb,$module,$sig );
	     $imod;
	     ($imod,$iname,$port,$l) = 
	     &rvp::get_next_signal_port_con($vdb)) {
	  print "DC:$imod,$iname,$port,\n";
	  if(&rvp::module_exists($vdb,$module)) {
		my $full_path =  $instance . "/" . $iname;
		$level++;
		my @sub_conns = &trace_sig_down_hier($vdb,$imod,$port,$full_path,$level);
		push @connections,@sub_conns;
	  }
	  my $sig_path;
	  if ($instance) {
		$sig_path = $instance . "/" . $port;
	  }else{
		$sig_path = $module . "/" . $port;
	  }
	  push @connections, $sig_path;
	  #print "SUB : $sig_path\n";
	}
  }

  return @connections;
}