simmel-bootloader/nRF5_SDK_11.0.0_89a8197/components/libraries/crc16/crc16.c
2018-02-07 23:32:49 +07:00

32 lines
917 B
C

/* 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 <stdlib.h>
uint16_t crc16_compute(uint8_t const * p_data, uint32_t size, uint16_t const * p_crc)
{
uint16_t crc = (p_crc == NULL) ? 0xFFFF : *p_crc;
for (uint32_t i = 0; i < size; i++)
{
crc = (uint8_t)(crc >> 8) | (crc << 8);
crc ^= p_data[i];
crc ^= (uint8_t)(crc & 0xFF) >> 4;
crc ^= (crc << 8) << 4;
crc ^= ((crc & 0xFF) << 4) << 1;
}
return crc;
}