From e54bd664a591615d1f9d61b0e167c467f635582c Mon Sep 17 00:00:00 2001
From: batt <batt@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Sun, 27 Sep 2009 09:16:45 +0000
Subject: [PATCH] Add CRC-CCITT algorithm.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@2972 38d2e660-2303-0410-9eaa-f027e97ec537
---
 bertos/algo/crc_ccitt.c | 84 +++++++++++++++++++++++++++++++++++++++++
 bertos/algo/crc_ccitt.h | 83 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 167 insertions(+)
 create mode 100644 bertos/algo/crc_ccitt.c
 create mode 100644 bertos/algo/crc_ccitt.h

diff --git a/bertos/algo/crc_ccitt.c b/bertos/algo/crc_ccitt.c
new file mode 100644
index 00000000..aed99147
--- /dev/null
+++ b/bertos/algo/crc_ccitt.c
@@ -0,0 +1,84 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2009 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief CRC-CCITT table and support routines
+ *
+ * \version $Id: crc.c 2770 2009-08-05 07:57:59Z  $
+ * \author Francesco Sacchi <batt@develer.com>
+ */
+
+#include "crc_ccitt.h"
+
+const uint16_t PROGMEM crc_ccitt_tab[256] = {
+	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78,
+};
+
+uint16_t crc_ccitt(uint16_t crc, const void *buffer, size_t len)
+{
+	const unsigned char *buf = (const unsigned char *)buffer;
+	while (len--)
+		crc = updcrc_ccitt(*buf++, crc);
+
+	return crc;
+}
+
diff --git a/bertos/algo/crc_ccitt.h b/bertos/algo/crc_ccitt.h
new file mode 100644
index 00000000..83f14548
--- /dev/null
+++ b/bertos/algo/crc_ccitt.h
@@ -0,0 +1,83 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2009 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief CCITT Cyclic Redundancy Check (CRC-CCITT).
+ *
+ * \note This algorithm is incompatible with the CRC16.
+ *
+ * \version $Id: crc.h 2771 2009-08-06 07:01:06Z lottaviano $
+ * \author Francesco Sacchi <batt@develer.com>
+ *
+ * $WIZ$ module_name = "crc-ccitt"
+ */
+
+#ifndef ALGO_CRC_CCITT_H
+#define ALGO_CRC_CCITT_H
+
+#include <cfg/compiler.h>
+#include <cpu/pgm.h>
+
+EXTERN_C_BEGIN
+
+/* CRC table */
+extern const uint16_t crc_ccitt_tab[256];
+
+/**
+ * \brief Compute the updated CRC-CCITT value for one octet (inline version)
+ */
+INLINE uint16_t updcrc_ccitt(uint8_t c, uint16_t oldcrc)
+{
+#if CPU_HARVARD
+	return (oldcrc >> 8) ^ pgm_read_uint16_t(crc_ccitt_tab[(oldcrc ^ c) & 0xff]);
+#else
+	return (oldcrc >> 8) ^ crc_ccitt_tab[(oldcrc ^ c) & 0xff];
+#endif
+}
+
+/** CRC-CCITT init value */
+#define CRC_CCITT_INIT_VAL ((uint16_t)0xFFFF)
+
+
+/**
+ * This function implements the CRC-CCITT calculation on a buffer.
+ *
+ * \param crc  Current CRC-CCITT value.
+ * \param buf  The buffer to perform CRC calculation on.
+ * \param len  The length of the Buffer.
+ *
+ * \return The updated CRC-CCITT value.
+ */
+extern uint16_t crc_ccitt(uint16_t crc, const void *buf, size_t len);
+
+EXTERN_C_END
+
+#endif /* ALGO_CRC_CCITT_H */
-- 
2.25.1