nestopia/source/core/board/NstBoardCxRom.cpp
2012-09-02 13:13:55 -04:00

115 lines
2.5 KiB
C++

////////////////////////////////////////////////////////////////////////////////////////
//
// Nestopia - NES/Famicom emulator written in C++
//
// Copyright (C) 2003-2008 Martin Freij
//
// This file is part of Nestopia.
//
// Nestopia is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// Nestopia is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Nestopia; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
////////////////////////////////////////////////////////////////////////////////////////
#include "NstBoard.hpp"
#include "NstBoardCxRom.hpp"
namespace Nes
{
namespace Core
{
namespace Boards
{
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("s", on)
#endif
CnRom::Ce::Ce(const Context& c)
: mask(0x0), state(0x0)
{
if (c.chr.Pin(26) == L"CE")
{
mask |= 0x1;
state |= 0x1;
}
else if (c.chr.Pin(26) == L"/CE")
{
mask |= 0x1;
state |= 0x0;
}
if (c.chr.Pin(27) == L"CE")
{
mask |= 0x2;
state |= 0x2;
}
else if (c.chr.Pin(27) == L"/CE")
{
mask |= 0x2;
state |= 0x0;
}
}
CnRom::CnRom(const Context& c)
: Board(c), ce(c) {}
void CnRom::SubReset(bool)
{
if (ce.mask)
{
Map( 0x8000U, 0xFFFFU, &CnRom::Poke_8000 );
}
else if (board == Type::STD_CNROM)
{
Map( CHR_SWAP_8K_BC );
}
else
{
Map( 0x8000U, 0xFFFFU, CHR_SWAP_8K );
}
}
void CpRom::SubReset(const bool hard)
{
Map( CHR_SWAP_4K_1_BC );
if (hard)
chr.SwapBank<SIZE_4K,0x1000>(0);
}
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("", on)
#endif
NES_ACCESSOR(CnRom,ChrOpenBus)
{
return 0xFF;
}
NES_POKE_AD(CnRom,8000)
{
data = GetBusData(address,data);
ppu.Update();
chr.SwapBank<SIZE_8K,0x0000>( data & ~ce.mask );
if ((data & ce.mask) == ce.state)
chr.ResetAccessor();
else
chr.SetAccessor( this, &CnRom::Access_ChrOpenBus );
}
}
}
}