static public CRCInfo GetCRCInfo(CRCType type)
{
CRCInfo param = null;
switch (type)
{
case CRCType.CRC16_IBM:
param = new CRCInfo(0x8005, 0x0000, true, true, 0x0000);
break;
case CRCType.CRC16_MAXIM:
param = new CRCInfo(0x8005, 0x0000, true, true, 0xFFFF);
break;
case CRCType.CRC16_USB:
param = new CRCInfo(0x8005, 0xFFFF, true, true, 0xFFFF);
break;
case CRCType.CRC16_MODBUS:
param = new CRCInfo(0x8005, 0xFFFF, true, true, 0x0000);
break;
case CRCType.CRC16_CCITT:
param = new CRCInfo(0x1021, 0x0000, true, true, 0x0000);
break;
case CRCType.CRC16_CCITT_FALSE:
param = new CRCInfo(0x1021, 0xFFFF, false, false, 0x0000);
break;
case CRCType.CRC16_X25:
param = new CRCInfo(0x1021, 0xFFFF, true, true, 0xFFFF);
break;
case CRCType.CRC16_XMODEM:
param = new CRCInfo(0x1021, 0x0000, false, false, 0x0000);
break;
case CRCType.CRC16_DNP:
param = new CRCInfo(0x3D65, 0x0000, true, true, 0xFFFF);
break;
case CRCType.CRC32:
param = new CRCInfo(0x04C11DB7, 0xFFFFFFFF, true, true, 0xFFFFFFFF);
break;
case CRCType.CRC32_MPEG2:
param = new CRCInfo(0x04C11DB7, 0xFFFFFFFF, false, false, 0x00000000);
break;
}
return(param);
}
static public UInt16 GetCRC16(CRCInfo param, byte[] data)
{
UInt16 crc = (UInt16)param.Init;
UInt16 Poly = 0;
UInt16 XorOut = (UInt16)param.XorOut;
if (param.RefIn)
{
for (int i = 0; i < 16; i++)
{
Poly <<= 1;
if ((param.Poly & (1u << i)) != 0)
{
Poly |= 0x01;
}
}
}
else
{
Poly = (UInt16)param.Poly;
}
foreach (byte b in data)
{
UInt16 bValue;
if (param.RefOut)
{
bValue = Convert.ToUInt16(b);
}
else
{
bValue = Convert.ToUInt16((UInt16)b << 8);
}
crc = Convert.ToUInt16(crc ^ bValue);
for (int i = 0; i < 8; i++)
{
if (param.RefOut)
{
if ((crc & 0x01) != 0)
{
crc >>= 1;
crc ^= Poly;
}
else
{
crc >>= 1;
}
}
else
{
if ((crc & 0x8000) != 0)
{
crc <<= 1;
crc ^= Poly;
}
else
{
crc <<= 1;
}
}
}
}
return(Convert.ToUInt16(crc ^ XorOut));
}
