Supermodel/Src/CPU/PowerPC/ppc603.c
Matthew Daniels e93c5d710f PowerPC IRQ line deassertion; DMA only fires interrupts when required
PowerPC no longer clears its own IRQ line; it is now cleared by the IRQ controller when there are no more pending interrupts. Not all games clear DMA interrupts so it was necessary to tweak the 53C810 SCSI controller and the Real3D DMA interface to only fire interrupts if a certain register is correctly set. 53C810 has the documented DIEN (DMA Interrupt Enable) register; Real3D DMA seems to use the low bit of the dmaConfig register.

Also I removed the net IRQ as no games seem to actually use it.
2021-11-28 01:11:11 +00:00

363 lines
8.6 KiB
C

/**
** Supermodel
** A Sega Model 3 Arcade Emulator.
** Copyright 2011 Bart Trzynadlowski, Nik Henson
**
** This file is part of Supermodel.
**
** Supermodel 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.
**
** Supermodel 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 Supermodel. If not, see <http://www.gnu.org/licenses/>.
**/
/*
* ppc603.c
*
* PowerPC 603e functions. Included from ppc.cpp; do not compile separately.
*/
void ppc603_exception(int exception)
{
#ifdef SUPERMODEL_DEBUGGER
if (PPCDebug != NULL)
PPCDebug->CPUException(exception);
#endif
switch( exception )
{
case EXCEPTION_IRQ: /* External Interrupt */
if( ppc_get_msr() & MSR_EE ) {
UINT32 msr = ppc_get_msr();
SRR0 = ppc.npc;
SRR1 = msr & 0xff73;
msr &= ~(MSR_POW | MSR_EE | MSR_PR | MSR_FP | MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1 | MSR_IR | MSR_DR | MSR_RI);
if( msr & MSR_ILE )
msr |= MSR_LE;
else
msr &= ~MSR_LE;
ppc_set_msr(msr);
if( msr & MSR_IP )
ppc.npc = 0xfff00000 | 0x0500;
else
ppc.npc = 0x00000000 | 0x0500;
ppc_change_pc(ppc.npc);
}
break;
case EXCEPTION_DECREMENTER: /* Decrementer overflow exception */
if( ppc_get_msr() & MSR_EE ) {
UINT32 msr = ppc_get_msr();
SRR0 = ppc.npc;
SRR1 = msr & 0xff73;
msr &= ~(MSR_POW | MSR_EE | MSR_PR | MSR_FP | MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1 | MSR_IR | MSR_DR | MSR_RI);
if( msr & MSR_ILE )
msr |= MSR_LE;
else
msr &= ~MSR_LE;
ppc_set_msr(msr);
if( msr & MSR_IP )
ppc.npc = 0xfff00000 | 0x0900;
else
ppc.npc = 0x00000000 | 0x0900;
ppc.interrupt_pending &= ~0x2;
ppc_change_pc(ppc.npc);
}
break;
case EXCEPTION_TRAP: /* Program exception / Trap */
{
UINT32 msr = ppc_get_msr();
SRR0 = ppc.pc;
SRR1 = (msr & 0xff73) | 0x20000; /* 0x20000 = TRAP bit */
msr &= ~(MSR_POW | MSR_EE | MSR_PR | MSR_FP | MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1 | MSR_IR | MSR_DR | MSR_RI);
if( msr & MSR_ILE )
msr |= MSR_LE;
else
msr &= ~MSR_LE;
ppc_set_msr(msr);
if( msr & MSR_IP )
ppc.npc = 0xfff00000 | 0x0700;
else
ppc.npc = 0x00000000 | 0x0700;
ppc_change_pc(ppc.npc);
}
break;
case EXCEPTION_SYSTEM_CALL: /* System call */
{
UINT32 msr = ppc_get_msr();
SRR0 = ppc.npc;
SRR1 = (msr & 0xff73);
msr &= ~(MSR_POW | MSR_EE | MSR_PR | MSR_FP | MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1 | MSR_IR | MSR_DR | MSR_RI);
if( msr & MSR_ILE )
msr |= MSR_LE;
else
msr &= ~MSR_LE;
ppc_set_msr(msr);
if( msr & MSR_IP )
ppc.npc = 0xfff00000 | 0x0c00;
else
ppc.npc = 0x00000000 | 0x0c00;
ppc_change_pc(ppc.npc);
}
break;
case EXCEPTION_SMI:
if( ppc_get_msr() & MSR_EE ) {
UINT32 msr = ppc_get_msr();
SRR0 = ppc.npc;
SRR1 = msr & 0xff73;
msr &= ~(MSR_POW | MSR_EE | MSR_PR | MSR_FP | MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1 | MSR_IR | MSR_DR | MSR_RI);
if( msr & MSR_ILE )
msr |= MSR_LE;
else
msr &= ~MSR_LE;
ppc_set_msr(msr);
if( msr & MSR_IP )
ppc.npc = 0xfff00000 | 0x1400;
else
ppc.npc = 0x00000000 | 0x1400;
ppc.interrupt_pending &= ~0x4;
ppc_change_pc(ppc.npc);
}
break;
case EXCEPTION_DSI:
{
UINT32 msr = ppc_get_msr();
SRR0 = ppc.npc;
SRR1 = msr & 0xff73;
msr &= ~(MSR_POW | MSR_EE | MSR_PR | MSR_FP | MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1 | MSR_IR | MSR_DR | MSR_RI);
if( msr & MSR_ILE )
msr |= MSR_LE;
else
msr &= ~MSR_LE;
ppc_set_msr(msr);
if( msr & MSR_IP )
ppc.npc = 0xfff00000 | 0x0300;
else
ppc.npc = 0x00000000 | 0x0300;
ppc.interrupt_pending &= ~0x4;
ppc_change_pc(ppc.npc);
}
break;
case EXCEPTION_ISI:
{
UINT32 msr = ppc_get_msr();
SRR0 = ppc.npc;
SRR1 = msr & 0xff73;
msr &= ~(MSR_POW | MSR_EE | MSR_PR | MSR_FP | MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1 | MSR_IR | MSR_DR | MSR_RI);
if( msr & MSR_ILE )
msr |= MSR_LE;
else
msr &= ~MSR_LE;
ppc_set_msr(msr);
if( msr & MSR_IP )
ppc.npc = 0xfff00000 | 0x0400;
else
ppc.npc = 0x00000000 | 0x0400;
ppc.interrupt_pending &= ~0x4;
ppc_change_pc(ppc.npc);
}
break;
default:
ErrorLog("PowerPC triggered an unknown exception. Emulation halted until reset.");
DebugLog("PowerPC triggered an unknown exception (%d).\n", exception);
ppc.fatalError = true;
break;
}
}
static void ppc603_set_smi_line(int state)
{
if( state ) {
ppc.interrupt_pending |= 0x4;
}
}
static void ppc603_check_interrupts(void)
{
if (MSR & MSR_EE)
{
if (ppc.interrupt_pending != 0)
{
if (ppc.interrupt_pending & 0x1)
{
ppc603_exception(EXCEPTION_IRQ);
}
else if (ppc.interrupt_pending & 0x2)
{
ppc603_exception(EXCEPTION_DECREMENTER);
}
else if (ppc.interrupt_pending & 0x4)
{
ppc603_exception(EXCEPTION_SMI);
}
}
}
}
void ppc_reset(void)
{
ppc.fatalError = false; // reset the fatal error flag
ppc.pc = ppc.npc = 0xfff00100;
ppc_set_msr(0x40);
ppc_change_pc(ppc.pc);
ppc.hid0 = 1;
ppc.interrupt_pending = 0;
ppc.tb = 0;
ppc.timer_frac = 0;
DEC = 0xffffffff;
ppc.total_cycles = 0;
ppc.cur_cycles = 0;
ppc.icount = 0;
}
int ppc_execute(int cycles)
{
UINT32 opcode;
ppc.cur_cycles = cycles;
ppc.icount = cycles;
ppc.tb_base_icount = cycles + ppc.timer_frac;
ppc.dec_base_icount = cycles + ppc.timer_frac;
// Check if decrementer exception occurs during execution (exception occurs after decrementer
// has passed through zero)
if ((UINT32)(ppc.dec_base_icount / ppc.timer_ratio) > DEC)
ppc.dec_trigger_cycle = ppc.dec_base_icount - ((1 + DEC) * ppc.timer_ratio);
else
ppc.dec_trigger_cycle = 0x7fffffff;
ppc_change_pc(ppc.npc);
/*{
char string1[200];
char string2[200];
opcode = BSWAP32(*ppc.op);
DisassemblePowerPC(opcode, ppc.npc, string1, string2, true);
printf("%08X: %s %s\n", ppc.npc, string1, string2);
}*/
ppc603_check_interrupts();
#ifdef SUPERMODEL_DEBUGGER
if (PPCDebug != NULL)
PPCDebug->CPUActive();
#endif // SUPERMODEL_DEBUGGER
while( ppc.icount > 0 && !ppc.fatalError)
{
ppc.pc = ppc.npc;
// Debug breakpoints
/*
if (ppc.pc == 0x9d40)
{
printf("%X R3=%08X R4=%08X\n", ppc.pc, REG(3), REG(4));
}
*/
opcode = *ppc.op++; // Supermodel byte reverses each aligned word (converting them to little endian) so they can be fetched directly
ppc.npc = ppc.pc + 4;
#ifdef SUPERMODEL_DEBUGGER
if (PPCDebug != NULL)
{
while (PPCDebug->CPUExecute(ppc.pc, opcode, (PPCDebug->instrCount > 0 ? 1 : 0)))
opcode = *ppc.op++;
}
#endif // SUPERMODEL_DEBUGGER
switch(opcode >> 26)
{
case 19: optable19[(opcode >> 1) & 0x3ff](opcode); break;
case 31: optable31[(opcode >> 1) & 0x3ff](opcode); break;
case 59: optable59[(opcode >> 1) & 0x3ff](opcode); break;
case 63: optable63[(opcode >> 1) & 0x3ff](opcode); break;
default: optable[opcode >> 26](opcode); break;
}
ppc.icount--;
if (ppc.icount == ppc.dec_trigger_cycle)
{
ppc.interrupt_pending |= 0x2;
ppc603_check_interrupts();
}
//ppc603_check_interrupts();
}
#ifdef SUPERMODEL_DEBUGGER
if (PPCDebug != NULL)
PPCDebug->CPUInactive();
#endif // SUPERMODEL_DEBUGGER
// Update timebase and decrementer. Both are updated at same rate as specified by timer_ratio.
ppc.timer_frac = ((ppc.tb_base_icount - ppc.icount) % ppc.timer_ratio);
ppc.tb += ((ppc.tb_base_icount - ppc.icount) / ppc.timer_ratio);
DEC -= ((ppc.dec_base_icount - ppc.icount) / ppc.timer_ratio);
/*
{
char string1[200];
char string2[200];
opcode = BSWAP32(*ppc.op);
DisassemblePowerPC(opcode, ppc.npc, string1, string2, true);
printf("%08X: %s %s\n", ppc.npc, string1, string2);
}
*/
int executed = cycles - ppc.icount;
ppc.total_cycles += executed;
ppc.cur_cycles = 0;
ppc.icount = 0;
ppc.tb_base_icount = 0;
ppc.dec_base_icount = 0;
return executed;
}