CRC-ITU checksum function

[chowdotya]

If you have trouble with CRC-ITU checksum, you can use this PHP function:

Code: Select all

function crcx25($data) {
   $content = explode(' ',$data) ;
   $len = count($content) ;
   $n = 0 ;
   
   $crc = 0xFFFF;   
   while ($len > 0)
   {
      $crc ^= hexdec($content[$n]) ;
      for ($i=0; $i<8; $i++) {
         if ($crc & 1) $crc = ($crc >> 1) ^ 0x8408;
         else $crc >>= 1;
      }
      $n++ ;
      $len-- ;
   }
   
   return(~$crc);
}


Note:
1. example of $data format :

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$data = '05 30 45 85'

2. it will return decimal value.