Diff: Utilities/CRC8.cpp

Revision:

1:f60eafbf009a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Utilities/CRC8.cpp	Wed Apr 10 14:56:25 2019 +0300
@@ -0,0 +1,93 @@
+  /***************************************************************************
+* Copyright (C) 2017 Maxim Integrated Products, Inc., All Rights Reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a
+* copy of this software and associated documentation files (the "Software"),
+* to deal in the Software without restriction, including without limitation
+* the rights to use, copy, modify, merge, publish, distribute, sublicense,
+* and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included
+* in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+* OTHER DEALINGS IN THE SOFTWARE.
+*
+* Except as contained in this notice, the name of Maxim Integrated
+* Products, Inc. shall not be used except as stated in the Maxim Integrated
+* Products, Inc. Branding Policy.
+*
+* The mere transfer of this software does not imply any licenses
+* of trade secrets, proprietary technology, copyrights, patents,
+* trademarks, maskwork rights, or any other form of intellectual
+* property whatsoever. Maxim Integrated Products, Inc. retains all
+* ownership rights.
+****************************************************************************
+*/
+#include <stdint.h>
+
+/*
+ * CRC-8:
+ *
+ * Width:   8
+ * Poly:    0x07
+ * Init:    0x00
+ * RefIn:   False
+ * RefOut:  False
+ * XOROur:  0x00
+ * Check:   0xF4
+ */
+
+static const uint8_t CRC8_POLY = 0x07;
+static bool crc8_initialized = false;
+
+static uint8_t crc8_table[256];
+
+
+static void init_crc8()
+{
+    uint8_t msb = 1 << 7;
+    uint8_t bit;
+    uint8_t rem;
+    uint32_t byte = 0;
+
+    if (crc8_initialized)
+        return;
+
+    while (byte < 256) {
+        rem = byte;
+        for (bit = 0; bit < 8; bit++) {
+            if (rem & msb)
+                rem = (rem << 1) ^ CRC8_POLY;
+            else
+                rem <<= 1;
+        }
+
+        crc8_table[byte++] = rem;
+    }
+
+    crc8_initialized = true;
+}
+
+uint8_t crc8(uint8_t *data, uint32_t length)
+{
+    uint8_t crc = 0x00;
+    uint32_t msg_idx = 0;
+
+    if (length == 0xFFFFFFFF)
+        return 0;
+
+    init_crc8();
+
+    while (msg_idx < length) {
+        crc = crc8_table[crc ^ data[msg_idx++]];
+    }
+
+    return crc;
+}