Diff: MaximInterfaceCore/crc.cpp

Revision:

7:9cd16581b578

Child:

8:5ea891c7d1a1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MaximInterfaceCore/crc.cpp	Mon Jul 22 11:44:07 2019 -0500
@@ -0,0 +1,81 @@
+/*******************************************************************************
+* 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 "crc.hpp"
+
+namespace MaximInterfaceCore {
+
+uint_fast8_t calculateCrc8(uint_fast8_t crc, uint_fast8_t data) {
+  // See Application Note 27
+  crc = (crc ^ data) & 0xFF;
+  for (int i = 0; i < 8; ++i) {
+    if (crc & 1) {
+      crc = (crc >> 1) ^ 0x8C;
+    } else {
+      crc = (crc >> 1);
+    }
+  }
+  return crc;
+}
+
+uint_fast8_t calculateCrc8(uint_fast8_t crc, span<const uint_least8_t> data) {
+  for (span<const uint_least8_t>::index_type i = 0; i < data.size(); ++i) {
+    crc = calculateCrc8(crc, data[i]);
+  }
+  return crc;
+}
+
+uint_fast16_t calculateCrc16(uint_fast16_t crc, uint_fast8_t data) {
+  static const uint_least8_t oddparity[] = {0, 1, 1, 0, 1, 0, 0, 1,
+                                            1, 0, 0, 1, 0, 1, 1, 0};
+
+  uint_fast16_t data16 = (data ^ crc) & 0xFF;
+  crc = (crc >> 8) & 0xFF;
+  if (oddparity[data16 & 0xF] ^ oddparity[data16 >> 4]) {
+    crc ^= 0xC001u;
+  }
+  data16 <<= 6;
+  crc ^= data16;
+  data16 <<= 1;
+  crc ^= data16;
+  return crc;
+}
+
+uint_fast16_t calculateCrc16(uint_fast16_t crc,
+                             span<const uint_least8_t> data) {
+  for (span<const uint_least8_t>::index_type i = 0; i < data.size(); ++i) {
+    crc = calculateCrc16(crc, data[i]);
+  }
+  return crc;
+}
+
+} // namespace MaximInterfaceCore