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Diff: nordic/app_common/crc16.cpp
- Revision:
- 0:eff01767de02
- Child:
- 65:98215c4f3a25
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/nordic/app_common/crc16.cpp Wed Mar 26 14:38:17 2014 +0000 @@ -0,0 +1,31 @@ +/* Copyright (c) 2013 Nordic Semiconductor. All Rights Reserved. + * + * The information contained herein is property of Nordic Semiconductor ASA. + * Terms and conditions of usage are described in detail in NORDIC + * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT. + * + * Licensees are granted free, non-transferable use of the information. NO + * WARRANTY of ANY KIND is provided. This heading must NOT be removed from + * the file. + * + */ + +#include "crc16.h" +#include <stdio.h> + +uint16_t crc16_compute(const uint8_t * p_data, uint32_t size, const uint16_t * p_crc) +{ + uint32_t i; + uint16_t crc = (p_crc == NULL) ? 0xffff : *p_crc; + + for (i = 0; i < size; i++) + { + crc = (unsigned char)(crc >> 8) | (crc << 8); + crc ^= p_data[i]; + crc ^= (unsigned char)(crc & 0xff) >> 4; + crc ^= (crc << 8) << 4; + crc ^= ((crc & 0xff) << 4) << 1; + } + + return crc; +}