Diff: nRF51822/nordic/app_common/crc16.cpp

Revision:

0:76dfa9657d9d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nRF51822/nordic/app_common/crc16.cpp	Wed Nov 12 02:40:34 2014 +0000
@@ -0,0 +1,31 @@
+/* Copyright (c) 2013 Nordic Semiconductor. All Rights Reserved.
+ *
+ * The information contained herein is property of Nordic Semiconductor ASA.
+ * Terms and conditions of usage are described in detail in NORDIC
+ * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
+ *
+ * Licensees are granted free, non-transferable use of the information. NO
+ * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
+ * the file.
+ *
+ */
+
+#include "crc16.h"
+#include <stdio.h>
+
+uint16_t crc16_compute(const uint8_t * p_data, uint32_t size, const uint16_t * p_crc)
+{
+    uint32_t i;
+    uint16_t crc = (p_crc == NULL) ? 0xffff : *p_crc;
+
+    for (i = 0; i < size; i++)
+    {
+        crc  = (unsigned char)(crc >> 8) | (crc << 8);
+        crc ^= p_data[i];
+        crc ^= (unsigned char)(crc & 0xff) >> 4;
+        crc ^= (crc << 8) << 4;
+        crc ^= ((crc & 0xff) << 4) << 1;
+    }
+
+    return crc;
+}