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Sigh: Another Z80 interrupt related bug fix. Avoid a loop when an INT occurs, but interrupts are disabled.

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon 2019-09-08 16:28:19 +01:00
parent 0e8813cdf3
commit 3e12ba6200
1 changed files with 30 additions and 25 deletions
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55
Z80/src/Z80.cpp
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@ -59,24 +59,21 @@ void EightBit::Z80::handleNMI() {
void EightBit::Z80::handleINT() {
IntelProcessor::handleINT();
raiseHALT();
if (IFF1()) {
di();
switch (IM()) {
case 0: // i8080 equivalent
execute(BUS().DATA());
break;
case 1:
restart(7 << 3);
tick(13);
break;
case 2:
call(MEMPTR() = register16_t(BUS().DATA(), IV()));
tick(19);
break;
default:
UNREACHABLE;
}
di();
switch (IM()) {
case 0: // i8080 equivalent
execute(BUS().DATA());
break;
case 1:
restart(7 << 3);
tick(13);
break;
case 2:
call(MEMPTR() = register16_t(BUS().DATA(), IV()));
tick(19);
break;
default:
UNREACHABLE;
}
}
@ -662,17 +659,25 @@ int EightBit::Z80::step() {
if (LIKELY(powered())) {
m_displaced = m_prefixCB = m_prefixDD = m_prefixED = m_prefixFD = false;
lowerM1();
if (UNLIKELY(lowered(RESET()))) {
bool handled = false;
if (lowered(RESET())) {
handleRESET();
} else if (UNLIKELY(lowered(NMI()))) {
handled = true;
} else if (lowered(NMI())) {
handleNMI();
} else if (UNLIKELY(lowered(INT()))) {
handleINT();
} else if (UNLIKELY(lowered(HALT()))) {
handled = true;
} else if (lowered(INT())) {
raiseHALT();
if (IFF1()) {
handleINT();
handled = true;
}
} else if (lowered(HALT())) {
execute(0); // NOP
} else {
execute(fetchByte());
handled = true;
}
if (!handled)
execute(fetchByte());
}
ExecutedInstruction.fire(*this);
return cycles();