Initial commit of OpenSPARC T2 architecture model.

[OpenSPARC-T2-SAM] / sam-t2 / sam / cpus / vonk / bl / lib / ecc / src / BL_HammingEcc.cc

// ========== Copyright Header Begin ==========================================
// 
// OpenSPARC T2 Processor File: BL_HammingEcc.cc
// Copyright (c) 2006 Sun Microsystems, Inc.  All Rights Reserved.
// DO NOT ALTER OR REMOVE COPYRIGHT NOTICES.
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// The above named program is free software; you can redistribute it and/or
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// ========== Copyright Header End ============================================
/************************************************************************
**  
**  Copyright (C) 2006, Sun Microsystems, Inc.
**
**  Sun considers its source code as an unpublished, proprietary
**  trade secret and it is available only under strict license provisions.
**  This copyright notice is placed here only to protect Sun in the event 
**  the source is deemed a published work. Disassembly, decompilation,
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*************************************************************************/
#include "BL_HammingEcc.h"
#include "BL_Hamming_22_6_Synd.h"
#include "BL_Hamming_32_7_Synd.h"
#include "BL_Hamming_64_8_Synd.h"

using namespace std;

uint64_t BL_HammingEcc::hamming_22_6_ecc_masks[] = 
{
   0xa65cb7,    // check bit 5
   0xfff800,    // check bit 4
   0xfc07f0,    // check bit 3
   0xc3c78e,    // check bit 2
   0x33366d,    // check bit 1
   0xaaad5b,    // check bit 0
};

uint64_t BL_HammingEcc::hamming_32_7_ecc_masks[] = 
{
   0x2da65cb7,    // check bit 6
   0xfc000000,    // check bit 5
   0x03fff800,    // check bit 4
   0x03fc07f0,    // check bit 3
   0xe3c3c78e,    // check bit 2
   0x9b33366d,    // check bit 1
   0x56aaad5b,    // check bit 0
};

uint64_t BL_HammingEcc::hamming_64_8_ecc_masks[] = 
{
    0x972cd2d32da65cb7,  // c7
    0xfe00000000000000,  // c6
    0x01fffffffc000000,  // c5
    0x01fffe0003fff800,  // c4
    0x01fe01fe03fc07f0,  // c3
    0xf1e1e1e1e3c3c78e,  // c2
    0xcd9999999b33366d,  // c1
    0xab55555556aaad5b,  // c0
};

#define HAMMING_22_6_ECC_MASKS (sizeof(hamming_22_6_ecc_masks)/sizeof(hamming_22_6_ecc_masks[0]))

#define HAMMING_32_7_ECC_MASKS (sizeof(hamming_32_7_ecc_masks)/sizeof(hamming_32_7_ecc_masks[0]))

#define HAMMING_64_8_ECC_MASKS (sizeof(hamming_64_8_ecc_masks)/sizeof(hamming_64_8_ecc_masks[0]))

BL_EccBits BL_HammingEcc::calc_check_bits(BL_HammingEccTypes type, uint64_t data)
{
  if (type == BL_Hamming_22_6)
  {
    return calc_checks(HAMMING_22_6_ECC_MASKS,hamming_22_6_ecc_masks,data);
  }
  else if (type == BL_Hamming_32_7)
  {
    return calc_checks(HAMMING_32_7_ECC_MASKS,hamming_32_7_ecc_masks,data);
  }
  else if (type == BL_Hamming_64_8)
  {
    return calc_checks(HAMMING_64_8_ECC_MASKS,hamming_64_8_ecc_masks,data);
  }
}

// This method generates an 22/6 hamming syndrome and returns the
// value Syndrome is the result of XOR'ing the calculated ecc value
// and stored ecc value
BL_Hamming_22_6_Synd BL_HammingEcc::get_hamming_22_6_synd(uint32_t data,
			       uint32_t stored_ecc_val)
{
  uint32_t calc_ecc_val =
    BL_HammingEcc::calc_check_bits(BL_Hamming_22_6, data).get();
  uint32_t syndrome = calc_ecc_val ^ stored_ecc_val;
  syndrome = BL_BaseSynd::maskedSyndrome(syndrome, data, stored_ecc_val, 5);
  return BL_Hamming_22_6_Synd(syndrome);
}

// This method generates a 32/7 syndrome and returns the value
// Syndrome is the result of XOR'ing the calculated ecc value and
// stored ecc value
BL_Hamming_32_7_Synd BL_HammingEcc::get_hamming_32_7_synd(uint32_t data,
			       uint32_t stored_ecc_val)
{
  uint32_t calc_ecc_val =
    BL_HammingEcc::calc_check_bits(BL_Hamming_32_7, data).get();
  uint32_t syndrome = calc_ecc_val ^ stored_ecc_val;
  syndrome = BL_BaseSynd::maskedSyndrome(syndrome, data, stored_ecc_val, 6);
  return BL_Hamming_32_7_Synd(syndrome);
}

// This method generates an 64/8 syndrome and returns the value
// Syndrome is the result of XOR'ing the calculated ecc value and
// stored ecc value
BL_Hamming_64_8_Synd BL_HammingEcc::get_hamming_64_8_synd(uint64_t data, 
                               uint64_t stored_ecc_val)
{
  uint64_t calc_ecc_val =
    BL_HammingEcc::calc_check_bits(BL_Hamming_64_8, data).get();
  uint64_t syndrome = calc_ecc_val ^ stored_ecc_val;
  syndrome = BL_BaseSynd::maskedSyndrome(syndrome, data, stored_ecc_val, 7);
  return BL_Hamming_64_8_Synd(syndrome);
}