Diff: lib/ble/src/crc16.c

Revision:

0:6ba9b94b8997

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/ble/src/crc16.c	Thu Feb 09 06:08:17 2017 +0000
@@ -0,0 +1,54 @@
+/* Copyright (c) Nordic Semiconductor ASA
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this
+ * list of conditions and the following disclaimer in the documentation and/or
+ * other materials provided with the distribution.
+ *
+ * 3. Neither the name of Nordic Semiconductor ASA nor the names of other
+ * contributors to this software may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * 4. This software must only be used in a processor manufactured by Nordic
+ * Semiconductor ASA, or in a processor manufactured by a third party that
+ * is used in combination with a processor manufactured by Nordic Semiconductor.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#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;
+}
+