/*
* 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
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