Maxim Integrated / MaximInterface

Device interface library for multiple platforms including Mbed.

Dependents:   DeepCover Embedded Security in IoT MaximInterface MAXREFDES155#

Maxim Interface is a library framework focused on providing flexible and expressive hardware interfaces. Both communication interfaces such as I2C and 1-Wire and device interfaces such as DS18B20 are supported. Modern C++ concepts are used extensively while keeping compatibility with C++98/C++03 and requiring no external dependencies. The embedded-friendly design does not depend on exceptions or RTTI.

The full version of the project is hosted on GitLab: https://gitlab.com/iabenz/MaximInterface

MaximInterfaceCore/Crc.cpp@9:fa054cc51fdb, 2019-09-27 (annotated)

Committer:
IanBenzMaxim
Date:
Fri Sep 27 16:19:38 2019 -0500
Revision:
9:fa054cc51fdb
Parent:
MaximInterfaceCore/crc.cpp@8:5ea891c7d1a1
Child:
10:947d3f44e0a0
Fixed file capitalization.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
IanBenzMaxim 7:9cd16581b578 1 /*******************************************************************************
IanBenzMaxim 8:5ea891c7d1a1 2 * Copyright (C) Maxim Integrated Products, Inc., All Rights Reserved.
IanBenzMaxim 7:9cd16581b578 3 *
IanBenzMaxim 7:9cd16581b578 4 * Permission is hereby granted, free of charge, to any person obtaining a
IanBenzMaxim 7:9cd16581b578 5 * copy of this software and associated documentation files (the "Software"),
IanBenzMaxim 7:9cd16581b578 6 * to deal in the Software without restriction, including without limitation
IanBenzMaxim 7:9cd16581b578 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
IanBenzMaxim 7:9cd16581b578 8 * and/or sell copies of the Software, and to permit persons to whom the
IanBenzMaxim 7:9cd16581b578 9 * Software is furnished to do so, subject to the following conditions:
IanBenzMaxim 7:9cd16581b578 10 *
IanBenzMaxim 7:9cd16581b578 11 * The above copyright notice and this permission notice shall be included
IanBenzMaxim 7:9cd16581b578 12 * in all copies or substantial portions of the Software.
IanBenzMaxim 7:9cd16581b578 13 *
IanBenzMaxim 7:9cd16581b578 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
IanBenzMaxim 7:9cd16581b578 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
IanBenzMaxim 7:9cd16581b578 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IanBenzMaxim 7:9cd16581b578 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
IanBenzMaxim 7:9cd16581b578 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
IanBenzMaxim 7:9cd16581b578 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
IanBenzMaxim 7:9cd16581b578 20 * OTHER DEALINGS IN THE SOFTWARE.
IanBenzMaxim 7:9cd16581b578 21 *
IanBenzMaxim 7:9cd16581b578 22 * Except as contained in this notice, the name of Maxim Integrated
IanBenzMaxim 7:9cd16581b578 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
IanBenzMaxim 7:9cd16581b578 24 * Products, Inc. Branding Policy.
IanBenzMaxim 7:9cd16581b578 25 *
IanBenzMaxim 7:9cd16581b578 26 * The mere transfer of this software does not imply any licenses
IanBenzMaxim 7:9cd16581b578 27 * of trade secrets, proprietary technology, copyrights, patents,
IanBenzMaxim 7:9cd16581b578 28 * trademarks, maskwork rights, or any other form of intellectual
IanBenzMaxim 7:9cd16581b578 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
IanBenzMaxim 7:9cd16581b578 30 * ownership rights.
IanBenzMaxim 7:9cd16581b578 31 *******************************************************************************/
IanBenzMaxim 7:9cd16581b578 32
IanBenzMaxim 8:5ea891c7d1a1 33 #include "Crc.hpp"
IanBenzMaxim 7:9cd16581b578 34
IanBenzMaxim 7:9cd16581b578 35 namespace MaximInterfaceCore {
IanBenzMaxim 7:9cd16581b578 36
IanBenzMaxim 7:9cd16581b578 37 uint_fast8_t calculateCrc8(uint_fast8_t crc, uint_fast8_t data) {
IanBenzMaxim 7:9cd16581b578 38 // See Application Note 27
IanBenzMaxim 7:9cd16581b578 39 crc = (crc ^ data) & 0xFF;
IanBenzMaxim 7:9cd16581b578 40 for (int i = 0; i < 8; ++i) {
IanBenzMaxim 7:9cd16581b578 41 if (crc & 1) {
IanBenzMaxim 7:9cd16581b578 42 crc = (crc >> 1) ^ 0x8C;
IanBenzMaxim 7:9cd16581b578 43 } else {
IanBenzMaxim 7:9cd16581b578 44 crc = (crc >> 1);
IanBenzMaxim 7:9cd16581b578 45 }
IanBenzMaxim 7:9cd16581b578 46 }
IanBenzMaxim 7:9cd16581b578 47 return crc;
IanBenzMaxim 7:9cd16581b578 48 }
IanBenzMaxim 7:9cd16581b578 49
IanBenzMaxim 7:9cd16581b578 50 uint_fast8_t calculateCrc8(uint_fast8_t crc, span<const uint_least8_t> data) {
IanBenzMaxim 7:9cd16581b578 51 for (span<const uint_least8_t>::index_type i = 0; i < data.size(); ++i) {
IanBenzMaxim 7:9cd16581b578 52 crc = calculateCrc8(crc, data[i]);
IanBenzMaxim 7:9cd16581b578 53 }
IanBenzMaxim 7:9cd16581b578 54 return crc;
IanBenzMaxim 7:9cd16581b578 55 }
IanBenzMaxim 7:9cd16581b578 56
IanBenzMaxim 7:9cd16581b578 57 uint_fast16_t calculateCrc16(uint_fast16_t crc, uint_fast8_t data) {
IanBenzMaxim 7:9cd16581b578 58 static const uint_least8_t oddparity[] = {0, 1, 1, 0, 1, 0, 0, 1,
IanBenzMaxim 7:9cd16581b578 59 1, 0, 0, 1, 0, 1, 1, 0};
IanBenzMaxim 7:9cd16581b578 60
IanBenzMaxim 7:9cd16581b578 61 uint_fast16_t data16 = (data ^ crc) & 0xFF;
IanBenzMaxim 7:9cd16581b578 62 crc = (crc >> 8) & 0xFF;
IanBenzMaxim 7:9cd16581b578 63 if (oddparity[data16 & 0xF] ^ oddparity[data16 >> 4]) {
IanBenzMaxim 7:9cd16581b578 64 crc ^= 0xC001u;
IanBenzMaxim 7:9cd16581b578 65 }
IanBenzMaxim 7:9cd16581b578 66 data16 <<= 6;
IanBenzMaxim 7:9cd16581b578 67 crc ^= data16;
IanBenzMaxim 7:9cd16581b578 68 data16 <<= 1;
IanBenzMaxim 7:9cd16581b578 69 crc ^= data16;
IanBenzMaxim 7:9cd16581b578 70 return crc;
IanBenzMaxim 7:9cd16581b578 71 }
IanBenzMaxim 7:9cd16581b578 72
IanBenzMaxim 7:9cd16581b578 73 uint_fast16_t calculateCrc16(uint_fast16_t crc,
IanBenzMaxim 7:9cd16581b578 74 span<const uint_least8_t> data) {
IanBenzMaxim 7:9cd16581b578 75 for (span<const uint_least8_t>::index_type i = 0; i < data.size(); ++i) {
IanBenzMaxim 7:9cd16581b578 76 crc = calculateCrc16(crc, data[i]);
IanBenzMaxim 7:9cd16581b578 77 }
IanBenzMaxim 7:9cd16581b578 78 return crc;
IanBenzMaxim 7:9cd16581b578 79 }
IanBenzMaxim 7:9cd16581b578 80
IanBenzMaxim 7:9cd16581b578 81 } // namespace MaximInterfaceCore