$line = 'Width = 32 <uart0_rx_data : 16\'h0000> Descr - "This is Register1 comment" f_name    bit_pos  RESERVED    31:8  RXDATA        5:0   </uart0_rx_data>';
if($line =~ m/^Width(\s*)\=(\s*)(\d*)/) # to match Width
{
  print "something";
}
elsif ($line =~ m/^Descr[\s]*-[\s]*[\w]+$/) # to match Descr
{
  print "noone";
}
else
{
  printf "Garbage found: \"%s\" \n",$line;
}