Goran Mahovlic / nRF51822_BLE_MIDI

Dependents:   BLE_MIDI

Fork of nRF51822 by Nordic Semiconductor

nordic/app_common/crc16.cpp@0:eff01767de02, 2014-03-26 (annotated)

Committer:
bogdanm
Date:
Wed Mar 26 14:38:17 2014 +0000
Revision:
0:eff01767de02
Child:
65:98215c4f3a25
Initial import of the nRF51822 code

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 0:eff01767de02 1 /* Copyright (c) 2013 Nordic Semiconductor. All Rights Reserved.
bogdanm 0:eff01767de02 2 *
bogdanm 0:eff01767de02 3 * The information contained herein is property of Nordic Semiconductor ASA.
bogdanm 0:eff01767de02 4 * Terms and conditions of usage are described in detail in NORDIC
bogdanm 0:eff01767de02 5 * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
bogdanm 0:eff01767de02 6 *
bogdanm 0:eff01767de02 7 * Licensees are granted free, non-transferable use of the information. NO
bogdanm 0:eff01767de02 8 * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
bogdanm 0:eff01767de02 9 * the file.
bogdanm 0:eff01767de02 10 *
bogdanm 0:eff01767de02 11 */
bogdanm 0:eff01767de02 12
bogdanm 0:eff01767de02 13 #include "crc16.h"
bogdanm 0:eff01767de02 14 #include <stdio.h>
bogdanm 0:eff01767de02 15
bogdanm 0:eff01767de02 16 uint16_t crc16_compute(const uint8_t * p_data, uint32_t size, const uint16_t * p_crc)
bogdanm 0:eff01767de02 17 {
bogdanm 0:eff01767de02 18 uint32_t i;
bogdanm 0:eff01767de02 19 uint16_t crc = (p_crc == NULL) ? 0xffff : *p_crc;
bogdanm 0:eff01767de02 20
bogdanm 0:eff01767de02 21 for (i = 0; i < size; i++)
bogdanm 0:eff01767de02 22 {
bogdanm 0:eff01767de02 23 crc = (unsigned char)(crc >> 8) | (crc << 8);
bogdanm 0:eff01767de02 24 crc ^= p_data[i];
bogdanm 0:eff01767de02 25 crc ^= (unsigned char)(crc & 0xff) >> 4;
bogdanm 0:eff01767de02 26 crc ^= (crc << 8) << 4;
bogdanm 0:eff01767de02 27 crc ^= ((crc & 0xff) << 4) << 1;
bogdanm 0:eff01767de02 28 }
bogdanm 0:eff01767de02 29
bogdanm 0:eff01767de02 30 return crc;
bogdanm 0:eff01767de02 31 }