static void UpdateIFR(SY6522_AY8910* pMB)
{
pMB->sy6522.IFR &= 0x7F;
if(pMB->sy6522.IFR & pMB->sy6522.IER & 0x7F)
pMB->sy6522.IFR |= 0x80;
// Now update the IRQ signal from all 6522s
// . OR-sum of all active TIMER1, TIMER2 & SPEECH sources (from all 6522s)
UINT bIRQ = 0;
for(UINT i=0; i<NUM_SY6522; i++)
bIRQ |= g_MB[i].sy6522.IFR & 0x80;
// NB. Mockingboard generates IRQ on both 6522s:
// . SSI263's IRQ (A/!R) is routed via the 2nd 6522 (at $Cx80) and must generate a 6502 IRQ (not NMI)
// . SC-01's IRQ (A/!R) is also routed via a (2nd?) 6522
// Phasor's SSI263 appears to be wired directly to the 6502's IRQ (ie. not via a 6522)
// . I assume Phasor's 6522s just generate 6502 IRQs (not NMIs)
if (bIRQ)
{
CpuIrqAssert(IS_6522);
}
else
{
CpuIrqDeassert(IS_6522);
}
}
static void UpdateIFR(SY6522_AY8910* pMB)
{
pMB->sy6522.IFR &= 0x7F;
if(pMB->sy6522.IFR & pMB->sy6522.IER & 0x7F)
pMB->sy6522.IFR |= 0x80;
// Now update the IRQ signal from all 6522s
// . OR-sum of all active TIMER1, TIMER2 & SPEECH sources (from all 6522s)
UINT bIRQ = 0;
for(UINT i=0; i<NUM_SY6522; i++)
bIRQ |= g_MB[i].sy6522.IFR & 0x80;
if (bIRQ)
if (pMB->nAY8910Number & 1)
CpuNmiAssert(IS_6522);
else
CpuIrqAssert(IS_6522);
else if (pMB->nAY8910Number & 1)
CpuNmiDeassert(IS_6522);
else
CpuIrqDeassert(IS_6522);
}
