Diff: mbutils.h

Revision:

0:0453a0a7e500

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbutils.h	Thu Apr 15 12:10:34 2010 +0000
@@ -0,0 +1,108 @@
+/* 
+ * FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
+ * Copyright (c) 2006 Christian Walter <wolti@sil.at>
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ *
+ * File: $Id: mbutils.h,v 1.5 2006/12/07 22:10:34 wolti Exp $
+ */
+
+#ifndef _MB_UTILS_H
+#define _MB_UTILS_H
+
+#ifdef __cplusplus
+PR_BEGIN_EXTERN_C
+#endif
+/*! \defgroup modbus_utils Utilities
+ *
+ * This module contains some utility functions which can be used by
+ * the application. It includes some special functions for working with
+ * bitfields backed by a character array buffer.
+ *
+ */
+/*! \addtogroup modbus_utils
+ *  @{
+ */
+/*! \brief Function to set bits in a byte buffer.
+ *
+ * This function allows the efficient use of an array to implement bitfields.
+ * The array used for storing the bits must always be a multiple of two
+ * bytes. Up to eight bits can be set or cleared in one operation.
+ *
+ * \param ucByteBuf A buffer where the bit values are stored. Must be a
+ *   multiple of 2 bytes. No length checking is performed and if
+ *   usBitOffset / 8 is greater than the size of the buffer memory contents
+ *   is overwritten.
+ * \param usBitOffset The starting address of the bits to set. The first
+ *   bit has the offset 0.
+ * \param ucNBits Number of bits to modify. The value must always be smaller
+ *   than 8.
+ * \param ucValues Thew new values for the bits. The value for the first bit
+ *   starting at <code>usBitOffset</code> is the LSB of the value
+ *   <code>ucValues</code>
+ *
+ * \code
+ * ucBits[2] = {0, 0};
+ *
+ * // Set bit 4 to 1 (read: set 1 bit starting at bit offset 4 to value 1)
+ * xMBUtilSetBits( ucBits, 4, 1, 1 );
+ *
+ * // Set bit 7 to 1 and bit 8 to 0.
+ * xMBUtilSetBits( ucBits, 7, 2, 0x01 );
+ *
+ * // Set bits 8 - 11 to 0x05 and bits 12 - 15 to 0x0A;
+ * xMBUtilSetBits( ucBits, 8, 8, 0x5A);
+ * \endcode
+ */
+void            xMBUtilSetBits( UCHAR * ucByteBuf, USHORT usBitOffset,
+                                UCHAR ucNBits, UCHAR ucValues );
+
+/*! \brief Function to read bits in a byte buffer.
+ *
+ * This function is used to extract up bit values from an array. Up to eight
+ * bit values can be extracted in one step.
+ *
+ * \param ucByteBuf A buffer where the bit values are stored.
+ * \param usBitOffset The starting address of the bits to set. The first
+ *   bit has the offset 0.
+ * \param ucNBits Number of bits to modify. The value must always be smaller
+ *   than 8.
+ *
+ * \code
+ * UCHAR ucBits[2] = {0, 0};
+ * UCHAR ucResult;
+ *
+ * // Extract the bits 3 - 10.
+ * ucResult = xMBUtilGetBits( ucBits, 3, 8 );
+ * \endcode
+ */
+UCHAR           xMBUtilGetBits( UCHAR * ucByteBuf, USHORT usBitOffset,
+                                UCHAR ucNBits );
+
+/*! @} */
+
+#ifdef __cplusplus
+PR_END_EXTERN_C
+#endif
+#endif