BizHawk/libmeteor/include/ameteor/dma.hpp

114 lines
2.3 KiB
C++

// Meteor - A Nintendo Gameboy Advance emulator
// Copyright (C) 2009-2011 Philippe Daouadi
//
// This program 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 3 of the License, or
// (at your option) any later version.
//
// This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
#ifndef __DMA_H__
#define __DMA_H__
#include <stdint.h>
#include <istream>
#include <ostream>
namespace AMeteor
{
class Dma
{
public :
enum Reason
{
Immediately = 0,
VBlank,
HBlank,
Special
};
Dma () :
m_graphic(false)
{ }
void Reset ();
bool GraphicDma () const
{
return false;
//return m_graphic;
}
void SetReload(uint8_t channum, uint16_t reload)
{
m_chans[channum].reload = reload;
}
void UpdateCnt (uint8_t channum);
void Check(uint8_t channum, uint8_t reason);
inline void CheckAll(uint8_t reason)
{
Check(0, reason);
Check(1, reason);
Check(2, reason);
Check(3, reason);
}
bool SaveState (std::ostream& stream);
bool LoadState (std::istream& stream);
private :
struct Channel
{
Channel () :
reload(0),
src(0),
dest(0),
count(0),
control(0)
{ }
uint16_t reload;
uint32_t src;
uint32_t dest;
uint16_t count;
union Control
{
Control(uint16_t v) :
w(v)
{ }
uint16_t w;
struct
{
unsigned int unused : 5;
unsigned int dest : 2;
unsigned int src : 2;
unsigned int repeat : 1;
unsigned int type : 1;
unsigned int drq : 1;
unsigned int start : 2;
unsigned int irq : 1;
unsigned int enable : 1;
} b;
} control;
};
Channel m_chans[4];
bool m_graphic;
void Process(uint8_t channel);
void Copy (uint32_t& src, uint32_t& dest, int8_t s_inc, int8_t d_inc,
uint32_t count, bool word);
};
}
#endif