From b055a0b6d0f972fa5de952dcc8405d346d90a12d Mon Sep 17 00:00:00 2001 From: Max Date: Fri, 22 Dec 2017 18:23:49 -0500 Subject: [PATCH] dstar CRC --- .../lib/CCITTChecksumReverse.cpp | 93 +++++++++++++++++++ .../lib/CCITTChecksumReverse.h | 39 ++++++++ 2 files changed, 132 insertions(+) create mode 100644 op25/gr-op25_repeater/lib/CCITTChecksumReverse.cpp create mode 100644 op25/gr-op25_repeater/lib/CCITTChecksumReverse.h diff --git a/op25/gr-op25_repeater/lib/CCITTChecksumReverse.cpp b/op25/gr-op25_repeater/lib/CCITTChecksumReverse.cpp new file mode 100644 index 0000000..0b5b0fb --- /dev/null +++ b/op25/gr-op25_repeater/lib/CCITTChecksumReverse.cpp @@ -0,0 +1,93 @@ +/* + * Copyright (C) 2009,2011,2014 by Jonathan Naylor, G4KLX + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include + +#include "CCITTChecksumReverse.h" + +static const unsigned short ccittTab[] = { + 0x0000,0x1189,0x2312,0x329b,0x4624,0x57ad,0x6536,0x74bf, + 0x8c48,0x9dc1,0xaf5a,0xbed3,0xca6c,0xdbe5,0xe97e,0xf8f7, + 0x1081,0x0108,0x3393,0x221a,0x56a5,0x472c,0x75b7,0x643e, + 0x9cc9,0x8d40,0xbfdb,0xae52,0xdaed,0xcb64,0xf9ff,0xe876, + 0x2102,0x308b,0x0210,0x1399,0x6726,0x76af,0x4434,0x55bd, + 0xad4a,0xbcc3,0x8e58,0x9fd1,0xeb6e,0xfae7,0xc87c,0xd9f5, + 0x3183,0x200a,0x1291,0x0318,0x77a7,0x662e,0x54b5,0x453c, + 0xbdcb,0xac42,0x9ed9,0x8f50,0xfbef,0xea66,0xd8fd,0xc974, + 0x4204,0x538d,0x6116,0x709f,0x0420,0x15a9,0x2732,0x36bb, + 0xce4c,0xdfc5,0xed5e,0xfcd7,0x8868,0x99e1,0xab7a,0xbaf3, + 0x5285,0x430c,0x7197,0x601e,0x14a1,0x0528,0x37b3,0x263a, + 0xdecd,0xcf44,0xfddf,0xec56,0x98e9,0x8960,0xbbfb,0xaa72, + 0x6306,0x728f,0x4014,0x519d,0x2522,0x34ab,0x0630,0x17b9, + 0xef4e,0xfec7,0xcc5c,0xddd5,0xa96a,0xb8e3,0x8a78,0x9bf1, + 0x7387,0x620e,0x5095,0x411c,0x35a3,0x242a,0x16b1,0x0738, + 0xffcf,0xee46,0xdcdd,0xcd54,0xb9eb,0xa862,0x9af9,0x8b70, + 0x8408,0x9581,0xa71a,0xb693,0xc22c,0xd3a5,0xe13e,0xf0b7, + 0x0840,0x19c9,0x2b52,0x3adb,0x4e64,0x5fed,0x6d76,0x7cff, + 0x9489,0x8500,0xb79b,0xa612,0xd2ad,0xc324,0xf1bf,0xe036, + 0x18c1,0x0948,0x3bd3,0x2a5a,0x5ee5,0x4f6c,0x7df7,0x6c7e, + 0xa50a,0xb483,0x8618,0x9791,0xe32e,0xf2a7,0xc03c,0xd1b5, + 0x2942,0x38cb,0x0a50,0x1bd9,0x6f66,0x7eef,0x4c74,0x5dfd, + 0xb58b,0xa402,0x9699,0x8710,0xf3af,0xe226,0xd0bd,0xc134, + 0x39c3,0x284a,0x1ad1,0x0b58,0x7fe7,0x6e6e,0x5cf5,0x4d7c, + 0xc60c,0xd785,0xe51e,0xf497,0x8028,0x91a1,0xa33a,0xb2b3, + 0x4a44,0x5bcd,0x6956,0x78df,0x0c60,0x1de9,0x2f72,0x3efb, + 0xd68d,0xc704,0xf59f,0xe416,0x90a9,0x8120,0xb3bb,0xa232, + 0x5ac5,0x4b4c,0x79d7,0x685e,0x1ce1,0x0d68,0x3ff3,0x2e7a, + 0xe70e,0xf687,0xc41c,0xd595,0xa12a,0xb0a3,0x8238,0x93b1, + 0x6b46,0x7acf,0x4854,0x59dd,0x2d62,0x3ceb,0x0e70,0x1ff9, + 0xf78f,0xe606,0xd49d,0xc514,0xb1ab,0xa022,0x92b9,0x8330, + 0x7bc7,0x6a4e,0x58d5,0x495c,0x3de3,0x2c6a,0x1ef1,0x0f78}; + +CCCITTChecksumReverse::CCCITTChecksumReverse() : +m_crc16(0xFFFFU) +{ +} + +CCCITTChecksumReverse::~CCCITTChecksumReverse() +{ +} + +void CCCITTChecksumReverse::update(const unsigned char* data, unsigned int length) +{ + assert(data != NULL); + + for (unsigned int i = 0U; i < length; i++) + m_crc16 = ((uint16_t)(m_crc8[1U])) ^ ccittTab[m_crc8[0U] ^ data[i]]; +} + +void CCCITTChecksumReverse::result(unsigned char* data) +{ + assert(data != NULL); + + m_crc16 = ~m_crc16; + + data[0U] = m_crc8[0U]; + data[1U] = m_crc8[1U]; +} + +bool CCCITTChecksumReverse::check(const unsigned char* data) +{ + assert(data != NULL); + + unsigned char sum[2U]; + result(sum); + + return sum[0U] == data[0U] && sum[1U] == data[1U]; +} + +void CCCITTChecksumReverse::reset() +{ + m_crc16 = 0xFFFFU; +} diff --git a/op25/gr-op25_repeater/lib/CCITTChecksumReverse.h b/op25/gr-op25_repeater/lib/CCITTChecksumReverse.h new file mode 100644 index 0000000..e60f93c --- /dev/null +++ b/op25/gr-op25_repeater/lib/CCITTChecksumReverse.h @@ -0,0 +1,39 @@ +/* + * Copyright (C) 2009,2011,2014 by Jonathan Naylor, G4KLX + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef CCITTChecksumReverse_H +#define CCITTChecksumReverse_H + +#include + +class CCCITTChecksumReverse { +public: + CCCITTChecksumReverse(); + ~CCCITTChecksumReverse(); + + void update(const unsigned char* data, unsigned int length); + + void result(unsigned char* data); + + bool check(const unsigned char* data); + + void reset(); + +private: + union { + uint16_t m_crc16; + uint8_t m_crc8[2U]; + }; +}; + +#endif