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Diffstat (limited to 'thirdparty/nRF5_SDK_15.0.0_a53641a/components/ant/ant_fs/crc.c')
-rw-r--r-- | thirdparty/nRF5_SDK_15.0.0_a53641a/components/ant/ant_fs/crc.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/thirdparty/nRF5_SDK_15.0.0_a53641a/components/ant/ant_fs/crc.c b/thirdparty/nRF5_SDK_15.0.0_a53641a/components/ant/ant_fs/crc.c new file mode 100644 index 0000000..ee26d88 --- /dev/null +++ b/thirdparty/nRF5_SDK_15.0.0_a53641a/components/ant/ant_fs/crc.c @@ -0,0 +1,98 @@ +/** + * This software is subject to the ANT+ Shared Source License + * www.thisisant.com/swlicenses + * Copyright (c) Dynastream Innovations, Inc. 2012 + * 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 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 Dynastream nor the names of its + * contributors may be used to endorse or promote products + * derived from this software without specific prior + * written permission. + * + * The following actions are prohibited: + * 1) Redistribution of source code containing the ANT+ Network + * Key. The ANT+ Network Key is available to ANT+ Adopters. + * Please refer to http://thisisant.com to become an ANT+ + * Adopter and access the key. + * + * 2) Reverse engineering, decompilation, and/or disassembly of + * software provided in binary form under this license. + * + * 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 HEREBY + * 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; DAMAGE TO ANY DEVICE, 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. SOME STATES DO NOT ALLOW + * THE EXCLUSION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE + * ABOVE LIMITATIONS MAY NOT APPLY TO YOU. + * + */ +#include "crc.h" +#include "compiler_abstraction.h" + + +/**@brief Function for updating the current CRC-16 value for a single byte input. + * + * @param[in] current_crc The current calculated CRC-16 value. + * @param[in] byte The input data byte for the computation. + * + * @return The updated CRC-16 value, based on the input supplied. + */ +static __INLINE uint16_t crc16_get(uint16_t current_crc, uint8_t byte) +{ + static const uint16_t crc16_table[16] = + { + 0x0000, 0xCC01, 0xD801, 0x1400, 0xF001, 0x3C00, 0x2800, 0xE401, + 0xA001, 0x6C00, 0x7800, 0xB401, 0x5000, 0x9C01, 0x8801, 0x4400 + }; + + uint16_t temp; + + // Compute checksum of lower four bits of a byte. + temp = crc16_table[current_crc & 0xF]; + current_crc = (current_crc >> 4u) & 0x0FFFu; + current_crc = current_crc ^ temp ^ crc16_table[byte & 0xF]; + + // Now compute checksum of upper four bits of a byte. + temp = crc16_table[current_crc & 0xF]; + current_crc = (current_crc >> 4u) & 0x0FFFu; + current_crc = current_crc ^ temp ^ crc16_table[(byte >> 4u) & 0xF]; + + return current_crc; +} + + +uint16_t crc_crc16_update(uint16_t current_crc, const volatile void * p_data, uint32_t size) +{ + uint8_t * p_block = (uint8_t *)p_data; + + while (size != 0) + { + current_crc = crc16_get(current_crc, *p_block); + p_block++; + size--; + } + + return current_crc; +} |