nestopia/source/core/board/NstBoardBtlSmb2c.cpp
2012-09-02 13:13:55 -04:00

153 lines
3.6 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 "../NstTimer.hpp"
#include "NstBoard.hpp"
#include "NstBoardBtlSmb2c.hpp"
namespace Nes
{
namespace Core
{
namespace Boards
{
namespace Btl
{
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("s", on)
#endif
Smb2c::Smb2c(const Context& c)
:
Board (c),
prgLowerOffset (prg.Source().Size() - SIZE_8K - SIZE_4K - 0x5000),
irq (*c.cpu)
{}
void Smb2c::SubReset(const bool hard)
{
irq.Reset( hard, true );
if (hard)
prg.SwapBank<SIZE_32K,0x0000>(prg.Source().Size() >= SIZE_64K);
if (prg.Source().Size() >= SIZE_64K)
Map( 0x4022U, &Smb2c::Poke_4022 );
Map( 0x4122U, &Smb2c::Poke_4122 );
Map( 0x5000U, 0x7FFFU, &Smb2c::Peek_5000 );
}
void Smb2c::SubLoad(State::Loader& state,const dword baseChunk)
{
NST_VERIFY( baseChunk == (AsciiId<'B','2','C'>::V) );
if (baseChunk == AsciiId<'B','2','C'>::V)
{
while (const dword chunk = state.Begin())
{
if (chunk == AsciiId<'I','R','Q'>::V)
{
State::Loader::Data<3> data( state );
irq.unit.enabled = data[0] & 0x1;
irq.unit.count = data[1] | (data[2] << 8 & 0xF00);
}
state.End();
}
}
}
void Smb2c::SubSave(State::Saver& state) const
{
const byte data[3] =
{
irq.unit.enabled != 0,
irq.unit.count & 0xFF,
irq.unit.count >> 8
};
state.Begin( AsciiId<'B','2','C'>::V ).Begin( AsciiId<'I','R','Q'>::V ).Write( data ).End().End();
}
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("", on)
#endif
void Smb2c::Irq::Reset(const bool hard)
{
if (hard)
{
enabled = false;
count = 0;
}
}
bool Smb2c::Irq::Clock()
{
if (enabled)
{
count = (count + 1) & 0xFFF;
if (!count)
{
enabled = false;
return true;
}
}
return false;
}
NES_POKE_D(Smb2c,4022)
{
prg.SwapBank<SIZE_32K,0x0000>( data & 0x1 );
}
NES_POKE_D(Smb2c,4122)
{
irq.Update();
irq.ClearIRQ();
irq.unit.enabled = data & 0x3;
irq.unit.count = 0;
}
NES_PEEK_A(Smb2c,5000)
{
return *prg.Source().Mem( address + prgLowerOffset );
}
void Smb2c::Sync(Event event,Input::Controllers* controllers)
{
if (event == EVENT_END_FRAME)
irq.VSync();
Board::Sync( event, controllers );
}
}
}
}
}