181 lines
6.7 KiB
C++
Executable File
181 lines
6.7 KiB
C++
Executable File
/*===========================================================================
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FILE:
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CRC.cpp
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DESCRIPTION:
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16-bit LSB CRC computation/verification
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PUBLIC CLASSES AND METHODS:
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SetCRC()
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CheckCRC()
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CalculateCRC()
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Copyright (c) 2011, Code Aurora Forum. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of Code Aurora Forum nor
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the names of its contributors may be used to endorse or promote
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products derived from this software without specific prior written
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permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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===========================================================================*/
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//-----------------------------------------------------------------------------
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// Include Files
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//-----------------------------------------------------------------------------
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#include "StdAfx.h"
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#include "CRC.h"
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//---------------------------------------------------------------------------
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// Definitions
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//---------------------------------------------------------------------------
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// CRC intermediates
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static USHORT CRCTable[CRC_TABLE_SIZE] =
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{
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0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
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0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
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0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
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0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
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0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
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0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
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0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
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0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
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0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
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0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
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0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
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0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
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0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
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0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
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0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
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0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
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0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
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0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
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0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
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0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
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0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
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0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
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0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
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0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
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0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
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0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
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0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
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0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
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0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
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0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
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0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
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0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
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};
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/*=========================================================================*/
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// Free Methods
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/*=========================================================================*/
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/*===========================================================================
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METHOD:
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SetCRC (Free Method)
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DESCRIPTION:
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Calculate and append a 16-bit CRC to given data
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PARAMETERS:
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pData [ I ] - The data buffer
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dataLen [ I ] - The length of the above buffer
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RETURN VALUE:
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None
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===========================================================================*/
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void SetCRC(
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PBYTE pData,
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ULONG dataLen )
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{
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// Calculate CRC
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USHORT CRC = CalculateCRC( pData, dataLen * 8 );
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// Add CRC to data
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pData[dataLen] = (BYTE)(CRC & 0x00ff);
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pData[dataLen + 1] = (BYTE)(CRC >> 8);
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}
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/*===========================================================================
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METHOD:
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CheckCRC (Free Method)
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DESCRIPTION:
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Check the CRC validity of the given data
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PARAMETERS:
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pData [ I ] - The data buffer
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dataLen [ I ] - The length of the above buffer
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RETURN VALUE:
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bool:
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true - CRC checks out OK
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false - CRC doesn't cut the mustard
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===========================================================================*/
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bool CheckCRC(
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const BYTE * pData,
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ULONG dataLen )
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{
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// There must be data
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ASSERT( pData != 0 );
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ASSERT( dataLen > 0 );
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// Calculate CRC
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USHORT CRC = CalculateCRC( pData, dataLen * 8 );
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return (CRC == CRC_16_L_OK ? true : false);
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}
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/*===========================================================================
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METHOD:
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CalculateCRC (Free Method)
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DESCRIPTION:
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Calculate a 16-bit CRC value
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PARAMETERS:
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pBuf [ I ] - The data buffer
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bitLen [ I ] - The length of the above buffer (in bits)
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RETURN VALUE:
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USHORT: The 16-bit calculated CRC
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===========================================================================*/
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USHORT CalculateCRC(
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const BYTE * pBuf,
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ULONG bitLen )
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{
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// Remainders are not allowed
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ASSERT( bitLen % 8 == 0 );
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// There must be a buffer
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ASSERT( pBuf != 0 );
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USHORT CRC;
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for (CRC = CRC_16_L_SEED; bitLen >= 8; bitLen -= 8, pBuf++)
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{
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CRC = CRCTable[(CRC ^ *pBuf) & 0x00ff] ^ (CRC >> 8);
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}
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return ~CRC;
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}
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