nestopia/source/core/board/NstBoardSunsoft3.cpp
2012-09-02 13:13:55 -04:00

149 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 "NstBoard.hpp"
#include "NstBoardSunsoft3.hpp"
namespace Nes
{
namespace Core
{
namespace Boards
{
namespace Sunsoft
{
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("s", on)
#endif
S3::S3(const Context& c)
:
Board (c),
irq (*c.cpu)
{}
void S3::Irq::Reset(const bool hard)
{
if (hard)
{
enabled = false;
count = 0;
toggle = 0;
}
}
void S3::SubReset(const bool hard)
{
irq.Reset( hard, true );
Map( 0x8800U, 0x8FFFU, CHR_SWAP_2K_0 );
Map( 0x9800U, 0x9FFFU, CHR_SWAP_2K_1 );
Map( 0xA800U, 0xAFFFU, CHR_SWAP_2K_2 );
Map( 0xB800U, 0xBFFFU, CHR_SWAP_2K_3 );
Map( 0xC000U, 0xCFFFU, &S3::Poke_C000 );
Map( 0xD800U, 0xDFFFU, &S3::Poke_D800 );
Map( 0xE800U, 0xEFFFU, NMT_SWAP_VH01 );
Map( 0xF800U, 0xFFFFU, PRG_SWAP_16K_0 );
}
void S3::SubLoad(State::Loader& state,const dword baseChunk)
{
NST_VERIFY( baseChunk == (AsciiId<'S','3'>::V) );
if (baseChunk == AsciiId<'S','3'>::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.toggle = data[0] >> 1 & 0x1;
irq.unit.count = data[1] | data[2] << 8;
}
state.End();
}
}
}
void S3::SubSave(State::Saver& state) const
{
const byte data[3] =
{
(irq.unit.enabled ? 0x1U : 0x0U) | (irq.unit.toggle ? 0x2U : 0x0U),
irq.unit.count & 0xFF,
irq.unit.count >> 8
};
state.Begin( AsciiId<'S','3'>::V ).Begin( AsciiId<'I','R','Q'>::V ).Write( data ).End().End();
}
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("", on)
#endif
NES_POKE_D(S3,C000)
{
irq.Update();
if (irq.unit.toggle ^= 1)
irq.unit.count = (irq.unit.count & 0x00FF) | data << 8;
else
irq.unit.count = (irq.unit.count & 0xFF00) | data << 0;
}
NES_POKE_D(S3,D800)
{
irq.Update();
irq.unit.toggle = 0;
irq.unit.enabled = data & 0x10;
irq.ClearIRQ();
}
bool S3::Irq::Clock()
{
if (enabled && count && !--count)
{
enabled = false;
count = 0xFFFF;
return true;
}
return false;
}
void S3::Sync(Event event,Input::Controllers* controllers)
{
if (event == EVENT_END_FRAME)
irq.VSync();
Board::Sync( event, controllers );
}
}
}
}
}