/*******************************************************************************
* SDR Trunk
* Copyright (C) 2014 Dennis Sheirer
*
* 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, either version 3 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>
******************************************************************************/
package edac;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import bits.BinaryMessage;
/**
* P25 CRC check/correction methods
*/
public class CRCP25
{
private final static Logger mLog = LoggerFactory.getLogger( CRCP25.class );
/**
* CRC-CCITT 16-bit checksums for a message length of 80 bits plus 16
* additional checksums representing CRC checksum bit errors
*
* Generated by:
* CRCUtil.generate( 80, 16, 0x11021l, 0xFFFFl, true );
*/
public static final int[] CCITT_80_CHECKSUMS = new int[]
{
0x1BCB, 0x8DE5, 0xC6F2, 0x6B69, 0xB5B4, 0x52CA, 0x2175, 0x90BA, 0x404D,
0xA026, 0x5803, 0xAC01, 0xD600, 0x6310, 0x3998, 0x14DC, 0x27E, 0x92F,
0x8497, 0xC24B, 0xE125, 0xF092, 0x7059, 0xB82C, 0x5406, 0x2213, 0x9109,
0xC884, 0x6C52, 0x3E39, 0x9F1C, 0x479E, 0x2BDF, 0x95EF, 0xCAF7, 0xE57B,
0xF2BD, 0xF95E, 0x74BF, 0xBA5F, 0xDD2F, 0xEE97, 0xF74B, 0xFBA5, 0xFDD2,
0x76F9, 0xBB7C, 0x55AE, 0x22C7, 0x9163, 0xC8B1, 0xE458, 0x7A3C, 0x350E,
0x1297, 0x894B, 0xC4A5, 0xE252, 0x7939, 0xBC9C, 0x565E, 0x233F, 0x919F,
0xC8CF, 0xE467, 0xF233, 0xF919, 0xFC8C, 0x7656, 0x333B, 0x999D, 0xCCCE,
0x6E77, 0xB73B, 0xDB9D, 0xEDCE, 0x7EF7, 0xBF7B, 0xDFBD, 0xEFDE, 0x0001,
0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080, 0x0100, 0x0200,
0x0400, 0x0800, 0x1000, 0x2000, 0x4000, 0x8000
};
/**
* Confirmed Packet Data Unit CRC-9 checksums, generated by:
*
* long[] table = generate( 135, 9, 0x259l, 0x1FF, false, Parity.NONE );
*/
public static final int[] CRC9_CHECKSUMS = new int[]
{
0x1E7, 0x1F3, 0x1F9, 0x1FC, 0x0D2, 0x045, 0x122, 0x0BD, 0x15E, 0x083,
0x141, 0x1A0, 0x0FC, 0x052, 0x005, 0x102, 0x0AD, 0x156, 0x087, 0x143,
0x1A1, 0x1D0, 0x0C4, 0x04E, 0x00B, 0x105, 0x182, 0x0ED, 0x176, 0x097,
0x14B, 0x1A5, 0x1D2, 0x0C5, 0x162, 0x09D, 0x14E, 0x08B, 0x145, 0x1A2,
0x0FD, 0x17E, 0x093, 0x149, 0x1A4, 0x0FE, 0x053, 0x129, 0x194, 0x0E6,
0x05F, 0x12F, 0x197, 0x1CB, 0x1E5, 0x1F2, 0x0D5, 0x16A, 0x099, 0x14C,
0x08A, 0x069, 0x134, 0x0B6, 0x077, 0x13B, 0x19D, 0x1CE, 0x0CB, 0x165,
0x1B2, 0x0F5, 0x17A, 0x091, 0x148, 0x088, 0x068, 0x018, 0x020, 0x03C,
0x302, 0x035, 0x11A, 0x0A1, 0x150, 0x084, 0x06E, 0x01B, 0x10D, 0x186,
0x0EF, 0x177, 0x1BB, 0x1DD, 0x1EE, 0x0DB, 0x16D, 0x1B6, 0x0F7, 0x17B,
0x1BD, 0x1DE, 0x0C3, 0x161, 0x1B0, 0x0F4, 0x056, 0x007, 0x103, 0x181,
0x1C0, 0x0CC, 0x04A, 0x009, 0x104, 0x0AE, 0x07B, 0x13D, 0x19E, 0x0E3,
0x171, 0x1B8, 0x0F0, 0x054, 0x006, 0x02F, 0x117, 0x18B, 0x1C5, 0x1E2,
0x0DD, 0x16E, 0x09B, 0x14D, 0x1A6
};
/**
* CRC-32 checksums for PDU1 ( HEADER + 1 Block ) messages, generated by:
*
* CRCUtil.generate( 64, 32, 0x104C11DB7l, 0xFFFFFFFFl, true );
*/
public static final long[] PDU1_CHECKSUMS = new long[]
{
0x86FFAACCl, 0x411F5BBDl, 0xA08FADDEl, 0x52275834l, 0x2B7322C1l,
0x95B99160l, 0x48BC466Bl, 0xA45E2335l, 0xD22F119Al, 0x6B770616l,
0x37DB0DD0l, 0x198D0833l, 0x8CC68419l, 0xC663420Cl, 0x61512FDDl,
0xB0A897EEl, 0x5A34C52Cl, 0x2F7AEC4Dl, 0x97BD7626l, 0x49BE35C8l,
0x26BF943Fl, 0x935FCA1Fl, 0xC9AFE50Fl, 0xE4D7F287l, 0xF26BF943l,
0xF935FCA1l, 0xFC9AFE50l, 0x7C2DF1F3l, 0xBE16F8F9l, 0xDF0B7C7Cl,
0x6DE530E5l, 0xB6F29872l, 0x5919C2E2l, 0x2EEC6FAAl, 0x1516B90El,
0x08EBD25Cl, 0x061567F5l, 0x830AB3FAl, 0x43E5D726l, 0x23926548l,
0x13A9BC7Fl, 0x89D4DE3Fl, 0xC4EA6F1Fl, 0xE275378Fl, 0xF13A9BC7l,
0xF89D4DE3l, 0xFC4EA6F1l, 0xFE275378l, 0x7D732767l, 0xBEB993B3l,
0xDF5CC9D9l, 0xEFAE64ECl, 0x75B7BCADl, 0xBADBDE56l, 0x5F0D61F0l,
0x2DE63E23l, 0x96F31F11l, 0xCB798F88l, 0x67DC491Fl, 0xB3EE248Fl,
0xD9F71247l, 0xECFB8923l, 0xF67DC491l, 0xFB3EE248l, 0x00000001l,
0x00000002l, 0x00000004l, 0x00000008l, 0x00000010l, 0x00000020l,
0x00000040l, 0x00000080l, 0x00000100l, 0x00000200l, 0x00000400l,
0x00000800l, 0x00001000l, 0x00002000l, 0x00004000l, 0x00008000l,
0x00010000l, 0x00020000l, 0x00040000l, 0x00080000l, 0x00100000l,
0x00200000l, 0x00400000l, 0x00800000l, 0x01000000l, 0x02000000l,
0x04000000l, 0x08000000l, 0x10000000l, 0x20000000l, 0x40000000l,
0x80000000l
};
/**
* CRC-32 checksums for PDU2 ( HEADER + 2 Blocks ) messages, generated by:
*
* CRCUtil.generate( 160, 32, 0x104C11DB7l, 0xFFFFFFFFl, true );
*/
public static final long[] PDU2_CHECKSUMS = new long[]
{
0x9D231959l, 0xCE918CACl, 0x6528488Dl, 0xB2942446l, 0x5B2A9CF8l,
0x2FF5C0A7l, 0x97FAE053l, 0xCBFD7029l, 0xE5FEB814l, 0x709FD2D1l,
0xB84FE968l, 0x5E477A6Fl, 0xAF23BD37l, 0xD791DE9Bl, 0xEBC8EF4Dl,
0xF5E477A6l, 0x7892B508l, 0x3E29D45Fl, 0x9F14EA2Fl, 0xCF8A7517l,
0xE7C53A8Bl, 0xF3E29D45l, 0xF9F14EA2l, 0x7E98298Al, 0x3D2C9A1El,
0x1CF6C3D4l, 0x0C1BEF31l, 0x860DF798l, 0x41667517l, 0xA0B33A8Bl,
0xD0599D45l, 0xE82CCEA2l, 0x7676E98Al, 0x395BFA1El, 0x1ECD73D4l,
0x0D063731l, 0x86831B98l, 0x41210317l, 0xA090818Bl, 0xD04840C5l,
0xE8242062l, 0x76729EEAl, 0x3959C1AEl, 0x1ECC6E0Cl, 0x0D06B9DDl,
0x86835CEEl, 0x412120ACl, 0x22F01E8Dl, 0x91780F46l, 0x4ADC8978l,
0x270ECA67l, 0x93876533l, 0xC9C3B299l, 0xE4E1D94Cl, 0x7010627Dl,
0xB808313El, 0x5E649644l, 0x2D52C5F9l, 0x96A962FCl, 0x49343FA5l,
0xA49A1FD2l, 0x502D8132l, 0x2A764E42l, 0x175BA9FAl, 0x09CD5A26l,
0x068623C8l, 0x01239F3Fl, 0x8091CF9Fl, 0xC048E7CFl, 0xE02473E7l,
0xF01239F3l, 0xF8091CF9l, 0xFC048E7Cl, 0x7C62C9E5l, 0xBE3164F2l,
0x5D783CA2l, 0x2CDC908Al, 0x140EC69El, 0x0867ED94l, 0x06537811l,
0x8329BC08l, 0x43F450DFl, 0xA1FA286Fl, 0xD0FD1437l, 0xE87E8A1Bl,
0xF43F450Dl, 0xFA1FA286l, 0x7F6F5F98l, 0x3DD72117l, 0x9EEB908Bl,
0xCF75C845l, 0xE7BAE422l, 0x71BDFCCAl, 0x3ABE70BEl, 0x1F3FB684l,
0x0DFF5599l, 0x86FFAACCl, 0x411F5BBDl, 0xA08FADDEl, 0x52275834l,
0x2B7322C1l, 0x95B99160l, 0x48BC466Bl, 0xA45E2335l, 0xD22F119Al,
0x6B770616l, 0x37DB0DD0l, 0x198D0833l, 0x8CC68419l, 0xC663420Cl,
0x61512FDDl, 0xB0A897EEl, 0x5A34C52Cl, 0x2F7AEC4Dl, 0x97BD7626l,
0x49BE35C8l, 0x26BF943Fl, 0x935FCA1Fl, 0xC9AFE50Fl, 0xE4D7F287l,
0xF26BF943l, 0xF935FCA1l, 0xFC9AFE50l, 0x7C2DF1F3l, 0xBE16F8F9l,
0xDF0B7C7Cl, 0x6DE530E5l, 0xB6F29872l, 0x5919C2E2l, 0x2EEC6FAAl,
0x1516B90El, 0x08EBD25Cl, 0x061567F5l, 0x830AB3FAl, 0x43E5D726l,
0x23926548l, 0x13A9BC7Fl, 0x89D4DE3Fl, 0xC4EA6F1Fl, 0xE275378Fl,
0xF13A9BC7l, 0xF89D4DE3l, 0xFC4EA6F1l, 0xFE275378l, 0x7D732767l,
0xBEB993B3l, 0xDF5CC9D9l, 0xEFAE64ECl, 0x75B7BCADl, 0xBADBDE56l,
0x5F0D61F0l, 0x2DE63E23l, 0x96F31F11l, 0xCB798F88l, 0x67DC491Fl,
0xB3EE248Fl, 0xD9F71247l, 0xECFB8923l, 0xF67DC491l, 0xFB3EE248l,
0x00000001l, 0x00000002l, 0x00000004l, 0x00000008l, 0x00000010l,
0x00000020l, 0x00000040l, 0x00000080l, 0x00000100l, 0x00000200l,
0x00000400l, 0x00000800l, 0x00001000l, 0x00002000l, 0x00004000l,
0x00008000l, 0x00010000l, 0x00020000l, 0x00040000l, 0x00080000l,
0x00100000l, 0x00200000l, 0x00400000l, 0x00800000l, 0x01000000l,
0x02000000l, 0x04000000l, 0x08000000l, 0x10000000l, 0x20000000l,
0x40000000l, 0x80000000l
};
/**
* CRC-32 checksums for PDU3 ( HEADER + 3 Blocks ) messages, generated by:
*
* CRCUtil.generate( 256, 32, 0x104C11DB7l, 0xFFFFFFFFl, true );
*/
public static final long[] PDU3_CHECKSUMS = new long[]
{
0xAA5FA470l, 0x574F5CE3l, 0xABA7AE71l, 0xD5D3D738l, 0x68896547l,
0xB444B2A3l, 0xDA225951l, 0xED112CA8l, 0x74E8188Fl, 0xBA740C47l,
0xDD3A0623l, 0xEE9D0311l, 0xF74E8188l, 0x79C7CE1Fl, 0xBCE3E70Fl,
0xDE71F387l, 0xEF38F9C3l, 0xF79C7CE1l, 0xFBCE3E70l, 0x7F8791E3l,
0xBFC3C8F1l, 0xDFE1E478l, 0x6D907CE7l, 0xB6C83E73l, 0xDB641F39l,
0xEDB20F9Cl, 0x74B98915l, 0xBA5CC48Al, 0x5F4EEC9El, 0x2DC7F894l,
0x14837291l, 0x8A41B948l, 0x4740527Fl, 0xA3A0293Fl, 0xD1D0149Fl,
0xE8E80A4Fl, 0xF4740527l, 0xFA3A0293l, 0xFD1D0149l, 0xFE8E80A4l,
0x7D27CE89l, 0xBE93E744l, 0x5D297D79l, 0xAE94BEBCl, 0x552AD185l,
0xAA9568C2l, 0x572A3ABAl, 0x29F59386l, 0x169A4718l, 0x092DAD57l,
0x8496D6ABl, 0xC24B6B55l, 0xE125B5AAl, 0x72F2540El, 0x3B19A4DCl,
0x1FEC5CB5l, 0x8FF62E5Al, 0x459B99F6l, 0x20AD4220l, 0x12362FCBl,
0x891B17E5l, 0xC48D8BF2l, 0x60264B22l, 0x3273AB4Al, 0x1B595B7El,
0x0FCC2364l, 0x05869F69l, 0x82C34FB4l, 0x43012901l, 0xA1809480l,
0x52A0C49Bl, 0xA950624Dl, 0xD4A83126l, 0x68349648l, 0x367AC5FFl,
0x9B3D62FFl, 0xCD9EB17Fl, 0xE6CF58BFl, 0xF367AC5Fl, 0xF9B3D62Fl,
0xFCD9EB17l, 0xFE6CF58Bl, 0xFF367AC5l, 0xFF9B3D62l, 0x7DAD106Al,
0x3CB606EEl, 0x1C3B8DACl, 0x0C7D480Dl, 0x863EA406l, 0x417FDCD8l,
0x22DF60B7l, 0x916FB05Bl, 0xC8B7D82Dl, 0xE45BEC16l, 0x704D78D0l,
0x3A4632B3l, 0x9D231959l, 0xCE918CACl, 0x6528488Dl, 0xB2942446l,
0x5B2A9CF8l, 0x2FF5C0A7l, 0x97FAE053l, 0xCBFD7029l, 0xE5FEB814l,
0x709FD2D1l, 0xB84FE968l, 0x5E477A6Fl, 0xAF23BD37l, 0xD791DE9Bl,
0xEBC8EF4Dl, 0xF5E477A6l, 0x7892B508l, 0x3E29D45Fl, 0x9F14EA2Fl,
0xCF8A7517l, 0xE7C53A8Bl, 0xF3E29D45l, 0xF9F14EA2l, 0x7E98298Al,
0x3D2C9A1El, 0x1CF6C3D4l, 0x0C1BEF31l, 0x860DF798l, 0x41667517l,
0xA0B33A8Bl, 0xD0599D45l, 0xE82CCEA2l, 0x7676E98Al, 0x395BFA1El,
0x1ECD73D4l, 0x0D063731l, 0x86831B98l, 0x41210317l, 0xA090818Bl,
0xD04840C5l, 0xE8242062l, 0x76729EEAl, 0x3959C1AEl, 0x1ECC6E0Cl,
0x0D06B9DDl, 0x86835CEEl, 0x412120ACl, 0x22F01E8Dl, 0x91780F46l,
0x4ADC8978l, 0x270ECA67l, 0x93876533l, 0xC9C3B299l, 0xE4E1D94Cl,
0x7010627Dl, 0xB808313El, 0x5E649644l, 0x2D52C5F9l, 0x96A962FCl,
0x49343FA5l, 0xA49A1FD2l, 0x502D8132l, 0x2A764E42l, 0x175BA9FAl,
0x09CD5A26l, 0x068623C8l, 0x01239F3Fl, 0x8091CF9Fl, 0xC048E7CFl,
0xE02473E7l, 0xF01239F3l, 0xF8091CF9l, 0xFC048E7Cl, 0x7C62C9E5l,
0xBE3164F2l, 0x5D783CA2l, 0x2CDC908Al, 0x140EC69El, 0x0867ED94l,
0x06537811l, 0x8329BC08l, 0x43F450DFl, 0xA1FA286Fl, 0xD0FD1437l,
0xE87E8A1Bl, 0xF43F450Dl, 0xFA1FA286l, 0x7F6F5F98l, 0x3DD72117l,
0x9EEB908Bl, 0xCF75C845l, 0xE7BAE422l, 0x71BDFCCAl, 0x3ABE70BEl,
0x1F3FB684l, 0x0DFF5599l, 0x86FFAACCl, 0x411F5BBDl, 0xA08FADDEl,
0x52275834l, 0x2B7322C1l, 0x95B99160l, 0x48BC466Bl, 0xA45E2335l,
0xD22F119Al, 0x6B770616l, 0x37DB0DD0l, 0x198D0833l, 0x8CC68419l,
0xC663420Cl, 0x61512FDDl, 0xB0A897EEl, 0x5A34C52Cl, 0x2F7AEC4Dl,
0x97BD7626l, 0x49BE35C8l, 0x26BF943Fl, 0x935FCA1Fl, 0xC9AFE50Fl,
0xE4D7F287l, 0xF26BF943l, 0xF935FCA1l, 0xFC9AFE50l, 0x7C2DF1F3l,
0xBE16F8F9l, 0xDF0B7C7Cl, 0x6DE530E5l, 0xB6F29872l, 0x5919C2E2l,
0x2EEC6FAAl, 0x1516B90El, 0x08EBD25Cl, 0x061567F5l, 0x830AB3FAl,
0x43E5D726l, 0x23926548l, 0x13A9BC7Fl, 0x89D4DE3Fl, 0xC4EA6F1Fl,
0xE275378Fl, 0xF13A9BC7l, 0xF89D4DE3l, 0xFC4EA6F1l, 0xFE275378l,
0x7D732767l, 0xBEB993B3l, 0xDF5CC9D9l, 0xEFAE64ECl, 0x75B7BCADl,
0xBADBDE56l, 0x5F0D61F0l, 0x2DE63E23l, 0x96F31F11l, 0xCB798F88l,
0x67DC491Fl, 0xB3EE248Fl, 0xD9F71247l, 0xECFB8923l, 0xF67DC491l,
0xFB3EE248l, 0x00000001l, 0x00000002l, 0x00000004l, 0x00000008l,
0x00000010l, 0x00000020l, 0x00000040l, 0x00000080l, 0x00000100l,
0x00000200l, 0x00000400l, 0x00000800l, 0x00001000l, 0x00002000l,
0x00004000l, 0x00008000l, 0x00010000l, 0x00020000l, 0x00040000l,
0x00080000l, 0x00100000l, 0x00200000l, 0x00400000l, 0x00800000l,
0x01000000l, 0x02000000l, 0x04000000l, 0x08000000l, 0x10000000l,
0x20000000l, 0x40000000l, 0x80000000l
};
/**
* Performs error detection and single-bit error correction against the
* data blocks of a PDU1 message.
*/
public static BinaryMessage correctPDU1( BinaryMessage message )
{
return correctPDU( message, PDU1_CHECKSUMS, 224 );
}
/**
* Performs error detection and single-bit error correction against the
* data blocks of a PDU2 message.
*/
public static BinaryMessage correctPDU2( BinaryMessage message )
{
return correctPDU( message, PDU2_CHECKSUMS, 320 );
}
/**
* Performs error detection and single-bit error correction against the
* data blocks of a PDU3 message.
*/
public static BinaryMessage correctPDU3( BinaryMessage message )
{
return correctPDU( message, PDU3_CHECKSUMS, 416 );
}
public static BinaryMessage correctPDU( BinaryMessage message, long[] checksums, int crcStart )
{
long calculated = 0; //Starting value
int messageStart = 160;
/* Iterate the set bits and XOR running checksum with lookup value */
for (int i = message.nextSetBit( messageStart );
i >= messageStart && i < crcStart;
i = message.nextSetBit( i+1 ) )
{
calculated ^= checksums[ i - messageStart ];
}
long checksum = getLongChecksum( message, crcStart, 32 );
long error = calculated ^ checksum;
if( error == 0 || error == 0xFFFFFFFFl )
{
message.setCRC( CRC.PASSED );
return message;
}
else
{
int errorLocation = getBitError( error, checksums );
if( errorLocation >= 0 )
{
message.flip( errorLocation + messageStart );
message.setCRC( CRC.CORRECTED );
return message;
}
}
message.setCRC( CRC.FAILED_CRC );
return message;
}
/**
* Error detection and correction of single-bit errors for CCITT 16-bit
* CRC protected 80-bit messages.
*/
public static BinaryMessage correctCCITT80( BinaryMessage message,
int messageStart,
int crcStart )
{
int calculated = 0; //Starting value
/* Iterate the set bits and XOR running checksum with lookup value */
for (int i = message.nextSetBit( messageStart );
i >= messageStart && i < crcStart;
i = message.nextSetBit( i+1 ) )
{
calculated ^= CCITT_80_CHECKSUMS[ i - messageStart ];
}
int checksum = getIntChecksum( message, crcStart, 16 );
int residual = calculated ^ checksum;
if( residual == 0 || residual == 0xFFFF )
{
message.setCRC( CRC.PASSED );
return message;
}
else
{
int errorLocation = getBitError( residual, CCITT_80_CHECKSUMS );
if( errorLocation >= 0 )
{
message.flip( errorLocation + messageStart );
message.setCRC( CRC.CORRECTED );
return message;
}
}
message.setCRC( CRC.FAILED_CRC );
return message;
}
/**
* Error detection for CRC-9 protected Confirmed Packet Data blocks. These
* data blocks have a slightly complicated structure because the checksum
* is located between bits 7-15, within a 144 bit block. The checksums
* were generated assuming that the message is contiguous from 0 - 134 bits.
* No data correction is performed.
*/
public static CRC checkCRC9( BinaryMessage message, int messageStart )
{
int calculated = 0x0; //Initial fill of all ones
/* Iterate the set bits and XOR running checksum with lookup value */
for (int i = message.nextSetBit( messageStart );
i >= messageStart && i < messageStart + 144;
i = message.nextSetBit( i+1 ) )
{
/* message bits before the CRC */
if( i < ( messageStart + 7 ) )
{
calculated ^= CRC9_CHECKSUMS[ i - messageStart ];
}
/* message bits after the CRC */
else if( i > ( messageStart + 15 ) )
{
calculated ^= CRC9_CHECKSUMS[ i - messageStart - 9 ];
}
}
int checksum = message.getInt( messageStart + 7, messageStart + 15 );
int residual = calculated ^ checksum;
// mLog.debug( "CALC:" + calculated + " CHECK:" + checksum + " RESID:" + residual );
if( residual == 0 || residual == 0x1FF )
{
return CRC.PASSED;
}
return CRC.FAILED_CRC;
}
/**
* Performs Galois 24/12/7 error detection and correction against the 12
* encoded 24-bit message segments following the 64-bit NID in the message
*
* @return - true if all 12 segments of the message can be checked/corrected
*/
public static boolean correctGalois24( BinaryMessage tdulc )
{
boolean passes = true;
int x = 64;
while( x < tdulc.size() && passes )
{
tdulc = Golay24.checkAndCorrect( tdulc, x );
passes = tdulc.getCRC() == CRC.PASSED;
x += 24;
}
return passes;
}
/**
* Calculates the value of the message checksum as a long
*/
public static long getLongChecksum( BinaryMessage message,
int crcStart, int crcLength )
{
return message.getLong( crcStart, crcStart + crcLength - 1 );
}
/**
* Calculates the value of the message checksum as an integer
*/
public static int getIntChecksum( BinaryMessage message,
int crcStart, int crcLength )
{
return message.getInt( crcStart, crcStart + crcLength - 1 );
}
/**
* Identifies any single bit error position that matches the checksum error.
*/
public static int getBitError( long checksumError, long[] checksums )
{
for( int x = 0; x < checksums.length; x++ )
{
if( checksums[ x ] == checksumError )
{
return x;
}
}
return -1;
}
/**
* Identifies any single bit error position that matches the checksum error.
*/
public static int getBitError( int checksumError, int[] checksums )
{
for( int x = 0; x < checksums.length; x++ )
{
if( checksums[ x ] == checksumError )
{
return x;
}
}
return -1;
}
public static void main( String[] args )
{
String raw = "000000001000001100000001010001111011000100001010010001111100000000000101000000000000000001000000000000110000000000000001101010101010101010101010";
BinaryMessage message = BinaryMessage.load( raw );
mLog.debug( "MSG:" + message.toString() );
CRC results = checkCRC9( message, 0 );
mLog.debug( "COR:" + message.toString() );
mLog.debug( "Results: " + results.getDisplayText() );
}
}