| 1 | //----------------------------------------------------------------------------- |
| 2 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, |
| 3 | // at your option, any later version. See the LICENSE.txt file for the text of |
| 4 | // the license. |
| 5 | //----------------------------------------------------------------------------- |
| 6 | // CRC16 |
| 7 | //----------------------------------------------------------------------------- |
| 8 | |
| 9 | #include "crc16.h" |
| 10 | |
| 11 | unsigned short update_crc16( unsigned short crc, unsigned char c ) |
| 12 | { |
| 13 | unsigned short i, v, tcrc = 0; |
| 14 | |
| 15 | v = (crc ^ c) & 0xff; |
| 16 | for (i = 0; i < 8; i++) { |
| 17 | tcrc = ( (tcrc ^ v) & 1 ) ? ( tcrc >> 1 ) ^ 0x8408 : tcrc >> 1; |
| 18 | v >>= 1; |
| 19 | } |
| 20 | |
| 21 | return ((crc >> 8) ^ tcrc)&0xffff; |
| 22 | } |