Implementation of 1-Wire with added Alarm Search Functionality
Dependents: Max32630_One_Wire_Interface
Utilities/crc.cpp@142:85b71cfd617e, 2019-08-13 (annotated)
- Committer:
- mfruge
- Date:
- Tue Aug 13 14:42:37 2019 +0000
- Revision:
- 142:85b71cfd617e
- Parent:
- 139:f0e0a7976846
Added functions to ROMCommands to add Alarm Search functionality
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
j3 | 104:3f48daed532b | 1 | /******************************************************************//** |
j3 | 104:3f48daed532b | 2 | * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved. |
j3 | 104:3f48daed532b | 3 | * |
j3 | 104:3f48daed532b | 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
j3 | 104:3f48daed532b | 5 | * copy of this software and associated documentation files (the "Software"), |
j3 | 104:3f48daed532b | 6 | * to deal in the Software without restriction, including without limitation |
j3 | 104:3f48daed532b | 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
j3 | 104:3f48daed532b | 8 | * and/or sell copies of the Software, and to permit persons to whom the |
j3 | 104:3f48daed532b | 9 | * Software is furnished to do so, subject to the following conditions: |
j3 | 104:3f48daed532b | 10 | * |
j3 | 104:3f48daed532b | 11 | * The above copyright notice and this permission notice shall be included |
j3 | 104:3f48daed532b | 12 | * in all copies or substantial portions of the Software. |
j3 | 104:3f48daed532b | 13 | * |
j3 | 104:3f48daed532b | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
j3 | 104:3f48daed532b | 15 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
j3 | 104:3f48daed532b | 16 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
j3 | 104:3f48daed532b | 17 | * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES |
j3 | 104:3f48daed532b | 18 | * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
j3 | 104:3f48daed532b | 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
j3 | 104:3f48daed532b | 20 | * OTHER DEALINGS IN THE SOFTWARE. |
j3 | 104:3f48daed532b | 21 | * |
j3 | 104:3f48daed532b | 22 | * Except as contained in this notice, the name of Maxim Integrated |
j3 | 104:3f48daed532b | 23 | * Products, Inc. shall not be used except as stated in the Maxim Integrated |
j3 | 104:3f48daed532b | 24 | * Products, Inc. Branding Policy. |
j3 | 104:3f48daed532b | 25 | * |
j3 | 104:3f48daed532b | 26 | * The mere transfer of this software does not imply any licenses |
j3 | 104:3f48daed532b | 27 | * of trade secrets, proprietary technology, copyrights, patents, |
j3 | 104:3f48daed532b | 28 | * trademarks, maskwork rights, or any other form of intellectual |
j3 | 104:3f48daed532b | 29 | * property whatsoever. Maxim Integrated Products, Inc. retains all |
j3 | 104:3f48daed532b | 30 | * ownership rights. |
j3 | 104:3f48daed532b | 31 | **********************************************************************/ |
j3 | 104:3f48daed532b | 32 | |
j3 | 104:3f48daed532b | 33 | #include "Utilities/crc.h" |
IanBenzMaxim | 78:0cbbac7f2016 | 34 | |
IanBenzMaxim | 90:c233d1c265ff | 35 | namespace OneWire |
j3 | 80:83b0d879cc32 | 36 | { |
IanBenzMaxim | 90:c233d1c265ff | 37 | namespace crc |
j3 | 80:83b0d879cc32 | 38 | { |
IanBenzMaxim | 90:c233d1c265ff | 39 | uint8_t calculateCrc8(uint8_t crc8, uint8_t data) |
j3 | 80:83b0d879cc32 | 40 | { |
IanBenzMaxim | 90:c233d1c265ff | 41 | // See Application Note 27 |
IanBenzMaxim | 90:c233d1c265ff | 42 | crc8 = crc8 ^ data; |
IanBenzMaxim | 90:c233d1c265ff | 43 | for (int i = 0; i < 8; i++) |
IanBenzMaxim | 90:c233d1c265ff | 44 | { |
IanBenzMaxim | 90:c233d1c265ff | 45 | if (crc8 & 1) |
IanBenzMaxim | 90:c233d1c265ff | 46 | { |
IanBenzMaxim | 90:c233d1c265ff | 47 | crc8 = (crc8 >> 1) ^ 0x8c; |
IanBenzMaxim | 90:c233d1c265ff | 48 | } |
IanBenzMaxim | 90:c233d1c265ff | 49 | else |
IanBenzMaxim | 90:c233d1c265ff | 50 | { |
IanBenzMaxim | 90:c233d1c265ff | 51 | crc8 = (crc8 >> 1); |
IanBenzMaxim | 90:c233d1c265ff | 52 | } |
IanBenzMaxim | 90:c233d1c265ff | 53 | } |
IanBenzMaxim | 90:c233d1c265ff | 54 | |
IanBenzMaxim | 90:c233d1c265ff | 55 | return crc8; |
IanBenzMaxim | 90:c233d1c265ff | 56 | } |
IanBenzMaxim | 90:c233d1c265ff | 57 | |
IanBenzMaxim | 90:c233d1c265ff | 58 | uint8_t calculateCrc8(const uint8_t * data, size_t dataLen, uint8_t crc) |
IanBenzMaxim | 90:c233d1c265ff | 59 | { |
IanBenzMaxim | 90:c233d1c265ff | 60 | for (size_t i = 0; i < dataLen; i++) |
IanBenzMaxim | 90:c233d1c265ff | 61 | { |
IanBenzMaxim | 90:c233d1c265ff | 62 | crc = calculateCrc8(crc, data[i]); |
IanBenzMaxim | 90:c233d1c265ff | 63 | } |
IanBenzMaxim | 90:c233d1c265ff | 64 | return crc; |
j3 | 80:83b0d879cc32 | 65 | } |
IanBenzMaxim | 90:c233d1c265ff | 66 | |
IanBenzMaxim | 90:c233d1c265ff | 67 | uint16_t calculateCrc16(uint16_t crc16, uint16_t data) |
j3 | 80:83b0d879cc32 | 68 | { |
IanBenzMaxim | 90:c233d1c265ff | 69 | const uint16_t oddparity[] = { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 }; |
IanBenzMaxim | 90:c233d1c265ff | 70 | |
IanBenzMaxim | 90:c233d1c265ff | 71 | data = (data ^ (crc16 & 0xff)) & 0xff; |
IanBenzMaxim | 90:c233d1c265ff | 72 | crc16 >>= 8; |
IanBenzMaxim | 90:c233d1c265ff | 73 | |
IanBenzMaxim | 90:c233d1c265ff | 74 | if (oddparity[data & 0xf] ^ oddparity[data >> 4]) |
IanBenzMaxim | 90:c233d1c265ff | 75 | { |
IanBenzMaxim | 90:c233d1c265ff | 76 | crc16 ^= 0xc001; |
IanBenzMaxim | 90:c233d1c265ff | 77 | } |
IanBenzMaxim | 90:c233d1c265ff | 78 | |
IanBenzMaxim | 90:c233d1c265ff | 79 | data <<= 6; |
IanBenzMaxim | 90:c233d1c265ff | 80 | crc16 ^= data; |
IanBenzMaxim | 90:c233d1c265ff | 81 | data <<= 1; |
IanBenzMaxim | 90:c233d1c265ff | 82 | crc16 ^= data; |
IanBenzMaxim | 90:c233d1c265ff | 83 | |
IanBenzMaxim | 90:c233d1c265ff | 84 | return crc16; |
IanBenzMaxim | 90:c233d1c265ff | 85 | } |
IanBenzMaxim | 90:c233d1c265ff | 86 | |
j3 | 139:f0e0a7976846 | 87 | uint16_t calculateCrc16(const uint8_t * data, size_t dataLen, uint16_t crc) |
IanBenzMaxim | 90:c233d1c265ff | 88 | { |
j3 | 139:f0e0a7976846 | 89 | for (size_t i = 0; i < dataLen; i++) |
IanBenzMaxim | 90:c233d1c265ff | 90 | { |
IanBenzMaxim | 90:c233d1c265ff | 91 | crc = calculateCrc16(crc, data[i]); |
IanBenzMaxim | 90:c233d1c265ff | 92 | } |
IanBenzMaxim | 90:c233d1c265ff | 93 | return crc; |
j3 | 80:83b0d879cc32 | 94 | } |
j3 | 80:83b0d879cc32 | 95 | } |
j3 | 80:83b0d879cc32 | 96 | } |