public static bool Validate(byte[] buffer)
{
// Get hardware calculated 4 bit CRC from buffer
var crc = buffer[C7SerialCrcOffset + 1] & 0x0f;
// Re-calculate CRC based on data in buffer
var remainder = 0;
for (var bufferIndex = 0; bufferIndex < MemorySize; bufferIndex++)
{
// Get data byte in 16 bit form
var data = (int)buffer[bufferIndex];
// Mask byte containing CRC (from the CRC check itself)
// Note the whole byte is masked not just the 4 CRC bits,
// i.e. 4 bits of serial are excluded too
if (bufferIndex == C7SerialCrcOffset + 1)
data &= 0xff00;
// XOR data
remainder ^= data;
// XOR bits
for (var bits = 8; bits > 0; bits--)
{
if ((remainder & 0x8000) != 0)
remainder = (remainder << 1) ^ 0x3000;
else
remainder = remainder << 1;
}
}
// Final shift down to 4 bits produces CRC result
var crcCheck = 0x000f & (remainder >> 12);
// Return successful when CRC matches hardware
return crc == crcCheck;
}
