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CPU: Enabling 8-bit indexes must truncate the value of X/Y

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This commit is contained in:
Sour 2019-02-20 19:53:45 -05:00
parent 37b501122f
commit 011caf951c
1 changed files with 5 additions and 1 deletions
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6
Core/Cpu.Instructions.cpp
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@ -267,6 +267,11 @@ void Cpu::REP()
void Cpu::SEP() void Cpu::SEP()
{ {
SetFlags((uint8_t)_operand); SetFlags((uint8_t)_operand);
if(CheckFlag(ProcFlags::IndexMode8)) {
//Truncate X/Y when 8-bit indexes are enabled
_state.Y &= 0xFF;
_state.X &= 0xFF;
}
} }
/****************************** /******************************
@ -967,7 +972,6 @@ void Cpu::XCE()
if(_state.EmulationMode) { if(_state.EmulationMode) {
SetFlags(ProcFlags::IndexMode8 | ProcFlags::MemoryMode8); SetFlags(ProcFlags::IndexMode8 | ProcFlags::MemoryMode8);
//_state.A &= 0xFF;
_state.Y &= 0xFF; _state.Y &= 0xFF;
_state.X &= 0xFF; _state.X &= 0xFF;
_state.SP = 0x100 | (_state.SP & 0xFF); _state.SP = 0x100 | (_state.SP & 0xFF);