nandsparescheme.c

NAND Flash Driver for ARM9. Compiler used IAR.

/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support 
 * ----------------------------------------------------------------------------
 * Copyright (c) 2008, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
 * ----------------------------------------------------------------------------
 */

//------------------------------------------------------------------------------
//         Headers
//------------------------------------------------------------------------------

#include "NandSpareScheme.h"
#include <utility/assert.h>

//------------------------------------------------------------------------------
//         Exported variables
//------------------------------------------------------------------------------
/// Spare area placement scheme for 256 byte pages.
const struct NandSpareScheme nandSpareScheme256 = {

    // Bad block marker is at position #5
    5,
    // 3 ecc bytes
    3,
    // Ecc bytes positions
    {0, 1, 2},
    // 4 extra bytes
    4,
    // Extra bytes positions
    {3, 4, 6, 7}
};

/// Spare area placement scheme for 512 byte pages.
const struct NandSpareScheme nandSpareScheme512 = {

    // Bad block marker is at position #5
    5,
    // 6 ecc bytes
    6,
    // Ecc bytes positions
    {0, 1, 2, 3, 6, 7},
    // 8 extra bytes
    8,
    // Extra bytes positions
    {8, 9, 10, 11, 12, 13, 14, 15}
};

/// Spare area placement scheme for 2048 byte pages.
const struct NandSpareScheme nandSpareScheme2048 = {

    // Bad block marker is at position #0
    0,
    // 24 ecc bytes
    24, 
    // Ecc bytes positions
    {40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,
     59, 60, 61, 62, 63},
    // 38 extra bytes
    38,
    // Extra bytes positions
    {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
     22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39}
};

//------------------------------------------------------------------------------
//         Exported functions
//------------------------------------------------------------------------------

//------------------------------------------------------------------------------
/// Reads the bad block marker inside a spare area buffer using the provided
/// scheme.
/// \param scheme  Pointer to a NandSpareScheme instance.
/// \param spare  Spare area buffer.
/// \param marker  Pointer to the variable to store the bad block marker.
//------------------------------------------------------------------------------
void NandSpareScheme_ReadBadBlockMarker(
    const struct NandSpareScheme *scheme,
    const unsigned char *spare,
    unsigned char *marker)
{
    *marker = spare[scheme->badBlockMarkerPosition];
}

//------------------------------------------------------------------------------
/// Modifies the bad block marker inside a spare area, using the given scheme.
/// \param scheme  Pointer to a NandSpareScheme instance.
/// \param spare  Spare area buffer.
/// \param marker  Bad block marker to write.
//------------------------------------------------------------------------------
void NandSpareScheme_WriteBadBlockMarker(
    const struct NandSpareScheme *scheme,
    unsigned char *spare,
    unsigned char marker)
{
    spare[scheme->badBlockMarkerPosition] = marker;
}

//------------------------------------------------------------------------------
/// Reads ECC information from a spare area using the provided scheme.
/// \param scheme  Pointer to a NandSpareScheme instance.
/// \param spare  Spare area buffer.
/// \param ecc  ECC buffer.
//------------------------------------------------------------------------------
void NandSpareScheme_ReadEcc(
    const struct NandSpareScheme *scheme,
    const unsigned char *spare,
    unsigned char *ecc)
{
    unsigned int i;
    for (i=0; i < scheme->numEccBytes; i++) {

        ecc[i] = spare[scheme->eccBytesPositions[i]];
    }
}

//------------------------------------------------------------------------------
/// Writes ECC information in a spare area, using a particular scheme.
/// \param scheme  Pointer to a NandSpareScheme instance.
/// \param spare  Spare area buffer.
/// \param ecc  ECC buffer.
//------------------------------------------------------------------------------
void NandSpareScheme_WriteEcc(
    const struct NandSpareScheme *scheme,
    unsigned char *spare,
    const unsigned char *ecc)
{
    unsigned int i;
    for (i=0; i < scheme->numEccBytes; i++) {

        spare[scheme->eccBytesPositions[i]] = ecc[i];
    } 
}

//------------------------------------------------------------------------------
/// Reads extra bytes of information from a spare area, using the provided
/// scheme.
/// \param scheme  Pointer to a NandSpareScheme instance.
/// \param spare  Spare area buffer.
/// \param extra  Extra bytes buffer.
/// \param size  Number of extra bytes to read.
/// \param offset  Index where to read the first extra byte.
//------------------------------------------------------------------------------
void NandSpareScheme_ReadExtra(
    const struct NandSpareScheme *scheme,
    const unsigned char *spare,
    void *extra,
    unsigned char size,
    unsigned char offset)
{
    ASSERT((size + offset) < scheme->numExtraBytes,
           "NandSpareScheme_ReadExtra: Too many bytes\n\r");

    unsigned int i;
    for (i=0; i < size; i++) {

        ((unsigned char *) extra)[i] = spare[scheme->extraBytesPositions[i+offset]];
    }
}

//------------------------------------------------------------------------------
/// Write extra bytes of information inside a spare area, using the provided
/// scheme.
/// \param scheme  Pointer to a NandSpareScheme instance.
/// \param spare  Spare area buffer.
/// \param extra  Extra bytes to write.
/// \param size  Number of extra bytes to write.
/// \param offset  Index where to write the first extra byte.
//------------------------------------------------------------------------------
void NandSpareScheme_WriteExtra(
    const struct NandSpareScheme *scheme,
    unsigned char *spare,
    const void *extra,
    unsigned char size,
    unsigned char offset)
{
    ASSERT((size + offset) < scheme->numExtraBytes,
           "NandSpareScheme_WriteExtra: Too many bytes\n\r");

    unsigned int i;
    for (i=0; i < size; i++) {

        spare[scheme->extraBytesPositions[i+offset]] = ((unsigned char *) extra)[i];
    }
}