beetle-pce-fast-libretro/mednafen/psx/sio.cpp
2013-09-08 13:41:01 +02:00

107 lines
1.9 KiB
C++

/* Mednafen - Multi-system Emulator
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "psx.h"
#include "sio.h"
namespace MDFN_IEN_PSX
{
// Dummy implementation.
static uint16 Status;
static uint16 Mode;
static uint16 Control;
static uint16 BaudRate;
static uint32 DataBuffer;
void SIO_Power(void)
{
Status = 0;
Mode = 0;
Control = 0;
BaudRate = 0;
DataBuffer = 0;
}
uint32 SIO_Read(pscpu_timestamp_t timestamp, uint32 A)
{
uint32 ret = 0;
switch(A & 0xE)
{
default:
PSX_WARNING("[SIO] Unknown read: 0x%08x -- %d\n", A, timestamp);
break;
case 0x0:
//case 0x2:
ret = DataBuffer >> ((A & 2) * 8);
break;
case 0x4:
ret = Status;
break;
case 0x8:
ret = Mode;
break;
case 0xA:
ret = Control;
break;
case 0xE:
ret = BaudRate;
break;
}
return(ret >> ((A & 1) * 8));
}
void SIO_Write(pscpu_timestamp_t timestamp, uint32 A, uint32 V)
{
V <<= (A & 1) * 8;
switch(A & 0xE)
{
default:
PSX_WARNING("[SIO] Unknown write: 0x%08x 0x%08x -- %d\n", A, V, timestamp);
break;
case 0x0:
//case 0x2:
V <<= (A & 2) * 8;
DataBuffer = V;
break;
case 0x8:
Mode = V;
break;
case 0xA:
Control = V;
break;
case 0xE:
BaudRate = V;
break;
}
}
}