Nordic Semiconductor / nRF51822

Nordic stack and drivers for the mbed BLE API

Dependents:   BLE_ANCS_SDAPI BLE_temperature BLE_HeartRate writable_gatt ... more

TARGET_MCU_NRF51822/sdk/source/libraries/crc16/crc16.c@638:c90ae1400bf2, 2016-09-14 (annotated)

Committer:
Vincent Coubard
Date:
Wed Sep 14 14:39:43 2016 +0100
Revision:
638:c90ae1400bf2
Sync with bdab10dc0f90748b6989c8b577771bb403ca6bd8 from ARMmbed/mbed-os.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Vincent Coubard 638:c90ae1400bf2 1 /*
Vincent Coubard 638:c90ae1400bf2 2 * Copyright (c) Nordic Semiconductor ASA
Vincent Coubard 638:c90ae1400bf2 3 * All rights reserved.
Vincent Coubard 638:c90ae1400bf2 4 *
Vincent Coubard 638:c90ae1400bf2 5 * Redistribution and use in source and binary forms, with or without modification,
Vincent Coubard 638:c90ae1400bf2 6 * are permitted provided that the following conditions are met:
Vincent Coubard 638:c90ae1400bf2 7 *
Vincent Coubard 638:c90ae1400bf2 8 * 1. Redistributions of source code must retain the above copyright notice, this
Vincent Coubard 638:c90ae1400bf2 9 * list of conditions and the following disclaimer.
Vincent Coubard 638:c90ae1400bf2 10 *
Vincent Coubard 638:c90ae1400bf2 11 * 2. Redistributions in binary form must reproduce the above copyright notice, this
Vincent Coubard 638:c90ae1400bf2 12 * list of conditions and the following disclaimer in the documentation and/or
Vincent Coubard 638:c90ae1400bf2 13 * other materials provided with the distribution.
Vincent Coubard 638:c90ae1400bf2 14 *
Vincent Coubard 638:c90ae1400bf2 15 * 3. Neither the name of Nordic Semiconductor ASA nor the names of other
Vincent Coubard 638:c90ae1400bf2 16 * contributors to this software may be used to endorse or promote products
Vincent Coubard 638:c90ae1400bf2 17 * derived from this software without specific prior written permission.
Vincent Coubard 638:c90ae1400bf2 18 *
Vincent Coubard 638:c90ae1400bf2 19 *
Vincent Coubard 638:c90ae1400bf2 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
Vincent Coubard 638:c90ae1400bf2 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
Vincent Coubard 638:c90ae1400bf2 22 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
Vincent Coubard 638:c90ae1400bf2 23 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
Vincent Coubard 638:c90ae1400bf2 24 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
Vincent Coubard 638:c90ae1400bf2 25 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
Vincent Coubard 638:c90ae1400bf2 26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
Vincent Coubard 638:c90ae1400bf2 27 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
Vincent Coubard 638:c90ae1400bf2 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
Vincent Coubard 638:c90ae1400bf2 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Vincent Coubard 638:c90ae1400bf2 30 *
Vincent Coubard 638:c90ae1400bf2 31 */
Vincent Coubard 638:c90ae1400bf2 32
Vincent Coubard 638:c90ae1400bf2 33 #include "crc16.h"
Vincent Coubard 638:c90ae1400bf2 34 #include <stdio.h>
Vincent Coubard 638:c90ae1400bf2 35
Vincent Coubard 638:c90ae1400bf2 36 uint16_t crc16_compute(const uint8_t * p_data, uint32_t size, const uint16_t * p_crc)
Vincent Coubard 638:c90ae1400bf2 37 {
Vincent Coubard 638:c90ae1400bf2 38 uint32_t i;
Vincent Coubard 638:c90ae1400bf2 39 uint16_t crc = (p_crc == NULL) ? 0xffff : *p_crc;
Vincent Coubard 638:c90ae1400bf2 40
Vincent Coubard 638:c90ae1400bf2 41 for (i = 0; i < size; i++)
Vincent Coubard 638:c90ae1400bf2 42 {
Vincent Coubard 638:c90ae1400bf2 43 crc = (unsigned char)(crc >> 8) | (crc << 8);
Vincent Coubard 638:c90ae1400bf2 44 crc ^= p_data[i];
Vincent Coubard 638:c90ae1400bf2 45 crc ^= (unsigned char)(crc & 0xff) >> 4;
Vincent Coubard 638:c90ae1400bf2 46 crc ^= (crc << 8) << 4;
Vincent Coubard 638:c90ae1400bf2 47 crc ^= ((crc & 0xff) << 4) << 1;
Vincent Coubard 638:c90ae1400bf2 48 }
Vincent Coubard 638:c90ae1400bf2 49
Vincent Coubard 638:c90ae1400bf2 50 return crc;
Vincent Coubard 638:c90ae1400bf2 51 }