xio.c

Here an embedded System-on-Chip is build, in an Xilinx Spartan-3 FPGA with Microblaze as the process

/* $Id: xio.c,v 1.1 2007/05/15 08:32:58 mta Exp $ */
/******************************************************************************
*
*       XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
*       AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
*       SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
*       OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
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*       THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
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*       FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
*       WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
*       IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
*       REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
*       INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
*       FOR A PARTICULAR PURPOSE.
*
*       (c) Copyright 2007 Xilinx Inc.
*       All rights reserved.
*
******************************************************************************/
/*****************************************************************************/
/**
*
* @file xio.c
*
* Contains I/O functions for memory-mapped or non-memory-mapped I/O
* architectures.  These functions encapsulate generic CPU I/O requirements.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who  Date	 Changes
* ----- ---- -------- -------------------------------------------------------
* 1.00a rpm  11/07/03 Added InSwap/OutSwap routines for endian conversion
* 1.01a ecm  02/24/06 CR225908 corrected the extra curly braces in macros
*                     and bumped version to 1.01.a.
* 2.11a mta  03/21/07 Updated to new coding style.
*
* </pre>
*
* @note
*
* This file may contain architecture-dependent code.
*
******************************************************************************/

/***************************** Include Files *********************************/

#include "xio.h"
#include "xbasic_types.h"

/************************** Constant Definitions *****************************/


/**************************** Type Definitions *******************************/


/***************** Macros (Inline Functions) Definitions *********************/


/************************** Function Prototypes ******************************/


/*****************************************************************************/
/**
*
* Performs a 16-bit endian converion.
*
* @param	Source contains the value to be converted.
* @param	DestPtr contains a pointer to the location to put the
*		converted value.
*
* @return	None.
*
* @note		None.
*
******************************************************************************/
void XIo_EndianSwap16(u16 Source, u16 *DestPtr)
{
	*DestPtr = (u16) (((Source & 0xFF00) >> 8) | ((Source & 0x00FF) << 8));
}

/*****************************************************************************/
/**
*
* Performs a 32-bit endian converion.
*
* @param	Source contains the value to be converted.
* @param	DestPtr contains a pointer to the location to put the
*		converted value.
*
* @return	None.
*
* @note		None.
*
******************************************************************************/
void XIo_EndianSwap32(u32 Source, u32 *DestPtr)
{
	/* get each of the half words from the 32 bit word */

	u16 LoWord = (u16) (Source & 0x0000FFFF);
	u16 HiWord = (u16) ((Source & 0xFFFF0000) >> 16);

	/* byte swap each of the 16 bit half words */

	LoWord = (((LoWord & 0xFF00) >> 8) | ((LoWord & 0x00FF) << 8));
	HiWord = (((HiWord & 0xFF00) >> 8) | ((HiWord & 0x00FF) << 8));

	/* swap the half words before returning the value */

	*DestPtr = (u32) ((LoWord << 16) | HiWord);
}

/*****************************************************************************/
/**
*
* Performs an input operation for a 16-bit memory location by reading from the
* specified address and returning the byte-swapped value read from that
* address.
*
* @param	InAddress contains the address to perform the input
*		operation at.
*
* @return	The byte-swapped value read from the specified input address.
*
* @note		None.
*
******************************************************************************/
u16 XIo_InSwap16(XIo_Address InAddress)
{
	u16 InData;

	/* get the data then swap it */
	InData = XIo_In16(InAddress);

	return (u16) (((InData & 0xFF00) >> 8) | ((InData & 0x00FF) << 8));
}

/*****************************************************************************/
/**
*
* Performs an input operation for a 32-bit memory location by reading from the
* specified address and returning the byte-swapped value read from that
* address.
*
* @param	InAddress contains the address to perform the input
*		operation at.
*
* @return	The byte-swapped value read from the specified input address.
*
* @note		None.
*
******************************************************************************/
u32 XIo_InSwap32(XIo_Address InAddress)
{
	u32 InData;
	u32 SwapData;

	/* get the data then swap it */
	InData = XIo_In32(InAddress);
	XIo_EndianSwap32(InData, &SwapData);

	return SwapData;
}

/*****************************************************************************/
/**
*
* Performs an output operation for a 16-bit memory location by writing the
* specified value to the the specified address. The value is byte-swapped
* before being written.
*
* @param	OutAddress contains the address to perform the output
*		operation at.
* @param	Value contains the value to be output at the specified address.
*
* @return	None.
*
* @note		None.
*
******************************************************************************/
void XIo_OutSwap16(XIo_Address OutAddress, u16 Value)
{
	u16 OutData;

	/* swap the data then output it */
	OutData = (u16) (((Value & 0xFF00) >> 8) | ((Value & 0x00FF) << 8));

	XIo_Out16(OutAddress, OutData);
}

/*****************************************************************************/
/**
*
* Performs an output operation for a 32-bit memory location by writing the
* specified value to the the specified address. The value is byte-swapped
* before being written.
*
* @param	OutAddress contains the address at which the
*		output operation has to be done.
* @param	Value contains the value to be output at the specified address.
*
* @return	None.
*
* @note		None.
*
******************************************************************************/
void XIo_OutSwap32(XIo_Address OutAddress, u32 Value)
{
	u32 OutData;

	/* swap the data then output it */
	XIo_EndianSwap32(Value, &OutData);
	XIo_Out32(OutAddress, OutData);
}