37 lines
1.2 KiB
C
37 lines
1.2 KiB
C
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/****************************************************************************/
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/* CRC32 stuff taken and adapted from lib_crc version 1.16 : */
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/* Library : lib_crc */
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/* File : lib_crc.c */
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/* Author : Lammert Bies 1999-2008 */
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/* E-mail : info@lammertbies.nl */
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/****************************************************************************/
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/* the ATxmega series NVM CRC compatible polynom */
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/* on ATxmega you can do this much faster in hardware */
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#define P_32 0xEDB88320L
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#define D_32 0xFFFFFFFFL
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uint32_t crc_tab32_value(uint8_t address) {
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uint32_t result;
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uint8_t j;
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result = (uint32_t)address & 0xffL;
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for (j=0; j<8; j++) {
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if (result & 0x00000001L) result = (result >> 1) ^ P_32;
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else result = result >> 1;
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}
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return result;
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}
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uint32_t update_crc_32(uint32_t crc, uint8_t c) {
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uint32_t tmp, long_c;
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long_c = (uint32_t)c & 0xffL;
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tmp = crc ^ long_c;
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crc = (crc >> 8) ^ crc_tab32_value(tmp & 0xffL);
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return crc;
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}
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