mirror of https://gerrit.osmocom.org/osmo-tetra
74 lines
2.0 KiB
C
74 lines
2.0 KiB
C
/* (C) 2011 by Holger Hans Peter Freyther
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <stdio.h>
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#include "tetra_common.h"
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#include <lower_mac/crc_simple.h>
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int main(int argc, char **argv)
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{
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uint8_t input1[] = { 0x01 };
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uint16_t crc;
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crc = crc16_itut_bytes(0x0, input1, 8);
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printf("The CRC is now: %u/0x%x\n", crc, crc);
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crc = crc16_itut_bits(0x0, input1, 1);
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printf("The CRC is now: %d/0x%x\n", crc, crc);
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crc = crc16_itut_bytes(0xFFFF, input1, 8);
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printf("The CRC is now: %u/0x%x\n", crc, crc);
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crc = crc16_itut_bits(0xFFFF, input1, 1);
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printf("The CRC is now: %d/0x%x\n", crc, crc);
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/* actual CRC-CCIT usage */
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uint8_t input2[] = {
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0, 0, 0, 1, 0, 0, 0, 0,
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1, 0, 1, 1, 0, 0, 0, 0,
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1, 0, 1, 1, 1, 1, 1, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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1, 0, 0, 0, 0, 0, 1, 1,
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0, 0, 0, 0, 0, 1, 1, 1,
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1, 1, 0, 1, 0, 0, 1, 1,
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0, 0, 1, 1,
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/* checksum */
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1, 1, 0, 1, 1, 1, 1, 0,
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1, 1, 1, 1, 0, 0, 0, 1,
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/* tail bits */
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0, 0, 0, 0 };
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crc = ~crc16_itut_bits(0xffff, input2, 60);
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printf("The CRC is now: %d/0x%x\n", crc, crc);
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/* swap the bytes */
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crc = (crc << 8) | (crc >> 8);
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osmo_pbit2ubit(&input2[60], (uint8_t *)&crc, 16);
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crc = crc16_itut_bits(0xFFFF, input2, 60 + 16);
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printf("The CRC is now: %d/0x%x\n", crc, crc);
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if (crc == 0x1d0f)
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printf("Decoded successfully.\n");
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else
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printf("Failed to decode.\n");
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return 0;
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}
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