Initial commit

owCRC16.cs

@@ -0,0 +1,61 @@
+using System;
+
+namespace OneWireAPI
+{
+    internal class owCRC16
+    {
+        #region CRC lookup table
+
+        private static short[] m_aOddParity = { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 };
+
+        #endregion
+
+        #region Methods
+
+        public static int Calculate(byte[] nData, int iStart, int iEnd)
+        {
+            return Calculate(nData, iStart, iEnd, 0);
+        }
+
+        public static int Calculate(byte nData, int iInitialValue)
+        {
+            byte[] aData = new byte[1];
+
+            aData[0] = nData;
+
+            return Calculate(aData, 0, 0, iInitialValue);
+        }
+
+        public static int Calculate(byte[] nData, int iStart, int iEnd, int iInitialValue)
+        {
+            int iIndex;								// Loop index
+            int iCurrentCRC = iInitialValue;	// Current CRC accumulator
+
+            // Loop over all bytes in the input array
+            for (iIndex = iStart; iIndex <= iEnd; iIndex++)
+            {
+                // Get the current element of data
+                int iBuffer = nData[iIndex];
+
+                // Calculate the current CRC for this position
+                iBuffer = (iBuffer ^ (iCurrentCRC & 0xFF)) & 0xFF;
+
+                iCurrentCRC >>= 8;
+
+                if ((m_aOddParity[iBuffer & 0xF] ^ m_aOddParity[iBuffer >> 4]) != 0)
+                    iCurrentCRC ^= 0xC001;
+
+                iBuffer <<= 6;
+                iCurrentCRC ^= iBuffer;
+
+                iBuffer <<= 1;
+                iCurrentCRC ^= iBuffer;
+            }
+
+            // Return the final CRC value
+            return iCurrentCRC;
+        }
+
+        #endregion
+    }
+}