protected virtual byte[] Encapsulate(byte[] frame)
{
var result = new List <byte>();
foreach (var value in frame)
{
switch (value)
{
case END:
result.Add(ESC);
result.Add(ESC_END);
break;
case ESC:
result.Add(ESC);
result.Add(ESC_ESC);
break;
default:
result.Add(value);
break;
}
}
var engine = new CRCEngine(CRCType.CRC32CCITTPolynomial);
var crc = engine.CalculateCrc32(result, 0);
result.AddRange(new byte[] { (byte)(crc & 0xFF), (byte)((crc >> 8) & 0xFF), (byte)((crc >> 16) & 0xFF), (byte)((crc >> 24) & 0xFF) });
result.Add(END);
return(result.ToArray());
}
public EFR32_GPCRC()
{
gpcrc = new CRCEngine(DefaultPolynomial);
var registerMap = new Dictionary <long, DoubleWordRegister>
{
{ (long)Registers.Control, new DoubleWordRegister(this)
.WithFlag(0, changeCallback: (_, enable) => { isEnabled = enable; }, name: "EN")
.WithReservedBits(1, 3)
.WithFlag(4, changeCallback: (_, polySel) =>
{
if (polySel)
{
this.Log(LogLevel.Warning, "16-bit polynomial is not supported");
}
}, name: "POLYSEL")
.WithReservedBits(5, 3)
.WithTaggedFlag("BYTEMODE", 8)
.WithTag("BITEREVERSE", 9, 1)
.WithTaggedFlag("BYTEREVERSE", 10)
.WithReservedBits(11, 2)
.WithTaggedFlag("AUTOINIT", 13)
.WithReservedBits(14, 18) },
{ (long)Registers.Command, new DoubleWordRegister(this)
.WithFlag(0, FieldMode.Write, changeCallback: (_, value) => { if (value)
{
UpdateInitVal();
}
}, name: "INIT")
.WithReservedBits(1, 31) },
{ (long)Registers.Init, new DoubleWordRegister(this)
.WithValueField(0, 32, out initDataField, name: "INIT") },
{ (long)Registers.InputData, new DoubleWordRegister(this)
.WithValueField(0, 32, FieldMode.Write, writeCallback: (_, value) =>
{
crc.Value = gpcrc.CalculateCrc32(BitConverter.GetBytes(value), crc.Value);
}, name: "INPUTDATA") },
{ (long)Registers.Data, new DoubleWordRegister(this)
.WithValueField(0, 32, out crc, FieldMode.Read, name: "DATA") },
};
registers = new DoubleWordRegisterCollection(this, registerMap);
}
public static byte[] CalculateCRC(IEnumerable <byte> bytes, uint crcInitialValue = 0x0, CRCType crcPolynomial = CRCType.CRC16CCITTPolynomial)
{
uint crc = crcInitialValue;
CRCEngine crcEngine = new CRCEngine(crcPolynomial);
var crcLength = crcPolynomial.GetLength();
// Byte little endian order
switch (crcLength)
{
case 2:
crc = crcEngine.CalculateCrc16(bytes, (ushort)crc);
return(new[] { (byte)crc, (byte)(crc >> 8) });
case 4:
crc = crcEngine.CalculateCrc32(bytes, crc);
return(new[] { (byte)crc, (byte)(crc >> 8), (byte)(crc >> 16), (byte)(crc >> 24) });
default:
Logger.Log(LogLevel.Error, "Cannot calculate CRC of invalid length {0}", crcLength);
return(new byte[crcLength]);
}
}
