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cpu/cpu - Handle halt mode

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madmaurice 2023-08-29 23:30:31 +02:00
parent 077f834c28
commit 5cabe03d25
2 changed files with 12 additions and 1 deletions
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9
cpu/cpu.cpp
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@ -56,6 +56,9 @@ void Cpu::step()
{ {
if(!handleInterrupts()) // if no isr has been called, decode an instruction if(!handleInterrupts()) // if no isr has been called, decode an instruction
{ {
if (halted)
processed_mcycles += 4;
else
executeInstruction(); executeInstruction();
} }
} }
@ -77,6 +80,8 @@ void Cpu::reset()
state.IME = IME_OFF; state.IME = IME_OFF;
state.IE = 0; state.IE = 0;
state.IF = 0; state.IF = 0;
halted = false;
} }
u8 Cpu::readPC8() u8 Cpu::readPC8()
@ -225,6 +230,10 @@ bool Cpu::handleInterrupts()
// servicable interrupts (assuming IME is on) // servicable interrupts (assuming IME is on)
u8 si = state.IE & state.IF & INT_MASK; u8 si = state.IE & state.IF & INT_MASK;
// Once there's an interrupt we exit halt mode
if (si)
halted = false;
if (state.IME == IME_SCHEDULED) if (state.IME == IME_SCHEDULED)
state.IME = IME_ON; state.IME = IME_ON;
else if (state.IME == IME_ON && si != 0) else if (state.IME == IME_ON && si != 0)

2
cpu/cpu.h
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@ -91,6 +91,8 @@ struct Cpu_state {
u8 IE; u8 IE;
u8 IF; u8 IF;
bool halted;
void setAF(u16 v); void setAF(u16 v);
u16 getAF(); u16 getAF();