beetle-psx-libretro/mednafen/psx/irq.cpp
2015-07-24 15:59:40 +02:00

158 lines
3.0 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"
static uint16_t Asserted;
static uint16_t Mask;
static uint16_t Status;
#define Recalc() CPU->AssertIRQ(0, (bool)(Status & Mask))
void IRQ_Power(void)
{
Asserted = 0;
Status = 0;
Mask = 0;
Recalc();
}
int IRQ_StateAction(void *data, int load, int data_only)
{
SFORMAT StateRegs[] =
{
SFVAR(Asserted),
SFVAR(Mask),
SFVAR(Status),
SFEND
};
int ret = MDFNSS_StateAction(data, load, data_only, StateRegs, "IRQ");
if(load)
{
Recalc();
}
return(ret);
}
void IRQ_Assert(int which, bool status)
{
uint32_t old_Asserted = Asserted;
//PSX_WARNING("[IRQ] Assert: %d %d", which, status);
//if(which == IRQ_SPU && status && (Asserted & (1 << which)))
// MDFN_DispMessage("SPU IRQ glitch??");
Asserted &= ~(1 << which);
if(status)
{
Asserted |= 1 << which;
//Status |= 1 << which;
Status |= (old_Asserted ^ Asserted) & Asserted;
}
Recalc();
}
void IRQ_Write(uint32_t A, uint32_t V)
{
// FIXME if we ever have "accurate" bus emulation
V <<= (A & 3) * 8;
//printf("[IRQ] Write: 0x%08x 0x%08x --- PAD TEMP\n", A, V);
if(A & 4)
Mask = V;
else
{
Status &= V;
//Status |= Asserted;
}
Recalc();
}
uint32_t IRQ_Read(uint32_t A)
{
uint32_t ret = Status;
if(A & 4)
ret = Mask;
// FIXME: Might want to move this out to psx.cpp eventually.
ret |= 0x1F800000;
ret >>= (A & 3) * 8;
//printf("[IRQ] Read: 0x%08x 0x%08x --- PAD TEMP\n", A, ret);
return(ret);
}
void IRQ_Reset(void)
{
Asserted = 0;
Status = 0;
Mask = 0;
Recalc();
}
uint32_t IRQ_GetRegister(unsigned int which, char *special, const uint32_t special_len)
{
switch(which)
{
case IRQ_GSREG_ASSERTED:
return Asserted;
case IRQ_GSREG_STATUS:
return Status;
case IRQ_GSREG_MASK:
return Mask;
}
return 0;
}
void IRQ_SetRegister(unsigned int which, uint32_t value)
{
switch(which)
{
case IRQ_GSREG_ASSERTED:
Asserted = value;
break;
case IRQ_GSREG_STATUS:
Status = value;
break;
case IRQ_GSREG_MASK:
Mask = value;
break;
default:
return;
}
Recalc();
}