Mouse code for the MacroRat
Diff: mbed-dev/targets/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/crc16/crc16.c
- Revision:
- 18:6a4db94011d3
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed-dev/targets/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/crc16/crc16.c Sun May 14 23:18:57 2017 +0000 @@ -0,0 +1,58 @@ +/* + * Copyright (c) 2013 Nordic Semiconductor ASA + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this list + * of conditions and the following disclaimer. + * + * 2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA + * integrated circuit in a product or a software update for such product, must reproduce + * the above copyright notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be + * used to endorse or promote products derived from this software without specific prior + * written permission. + * + * 4. This software, with or without modification, must only be used with a + * Nordic Semiconductor ASA integrated circuit. + * + * 5. Any software provided in binary or object form under this license must not be reverse + * engineered, decompiled, modified and/or disassembled. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + + +#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; +}