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6502: All non-writes are affected by RDY.

This commit is contained in:
Anthony Konzel 2016-03-09 20:12:49 -06:00
parent bd7e10af6b
commit aa83c33c58
1 changed files with 85 additions and 65 deletions
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150
BizHawk.Emulation.Cores/CPUs/MOS 6502X/Execute.cs
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@ -534,7 +534,7 @@ namespace BizHawk.Emulation.Cores.Components.M6502
void FetchDummy()
{
DummyReadMemory(PC);
DummyReadMemory(PC);
}
public void Execute(int cycles)
@ -1152,45 +1152,59 @@ namespace BizHawk.Emulation.Cores.Components.M6502
}
void RelBranch_Stage3()
{
FetchDummy();
alu_temp = (byte)PC + (int)(sbyte)opcode2;
PC &= 0xFF00;
PC |= (ushort)((alu_temp & 0xFF));
if (alu_temp.Bit(8))
{
//we need to carry the add, and then we'll be ready to fetch the next instruction
opcode = VOP_RelativeStuff2;
mi = -1;
}
else
{
//to pass cpu_interrupts_v2/5-branch_delays_irq we need to handle a quirk here
//if we decide to interrupt in the next cycle, this condition will cause it to get deferred by one instruction
if (!interrupt_pending)
branch_irq_hack = true;
}
}
rdy_freeze = !RDY;
if (RDY)
{
FetchDummy();
alu_temp = (byte)PC + (int)(sbyte)opcode2;
PC &= 0xFF00;
PC |= (ushort)((alu_temp & 0xFF));
if (alu_temp.Bit(8))
{
//we need to carry the add, and then we'll be ready to fetch the next instruction
opcode = VOP_RelativeStuff2;
mi = -1;
}
else
{
//to pass cpu_interrupts_v2/5-branch_delays_irq we need to handle a quirk here
//if we decide to interrupt in the next cycle, this condition will cause it to get deferred by one instruction
if (!interrupt_pending)
branch_irq_hack = true;
}
}
}
void RelBranch_Stage4()
{
FetchDummy();
if (alu_temp.Bit(31))
PC = (ushort)(PC - 0x100);
else PC = (ushort)(PC + 0x100);
}
rdy_freeze = !RDY;
if (RDY)
{
FetchDummy();
if (alu_temp.Bit(31))
PC = (ushort)(PC - 0x100);
else PC = (ushort)(PC + 0x100);
}
}
void NOP()
{
}
void DecS()
rdy_freeze = !RDY;
}
void DecS()
{
S--;
}
rdy_freeze = !RDY;
if (RDY)
{
S--;
}
}
void IncS()
{
S++;
}
rdy_freeze = !RDY;
if (RDY)
{
S++;
}
}
void JSR()
{
rdy_freeze = !RDY;
@ -2041,35 +2055,50 @@ namespace BizHawk.Emulation.Cores.Components.M6502
}
void Imp_ASL_A()
{
FetchDummy();
FlagC = (A & 0x80) != 0;
A = (byte)(A << 1);
NZ_A();
}
rdy_freeze = !RDY;
if (RDY)
{
FetchDummy();
FlagC = (A & 0x80) != 0;
A = (byte)(A << 1);
NZ_A();
}
}
void Imp_ROL_A()
{
FetchDummy();
temp8 = A;
A = (byte)((A << 1) | (P & 1));
FlagC = (temp8 & 0x80) != 0;
NZ_A();
}
rdy_freeze = !RDY;
if (RDY)
{
FetchDummy();
temp8 = A;
A = (byte)((A << 1) | (P & 1));
FlagC = (temp8 & 0x80) != 0;
NZ_A();
}
}
void Imp_ROR_A()
{
FetchDummy();
temp8 = A;
A = (byte)((A >> 1) | ((P & 1) << 7));
FlagC = (temp8 & 1) != 0;
NZ_A();
}
rdy_freeze = !RDY;
if (RDY)
{
FetchDummy();
temp8 = A;
A = (byte)((A >> 1) | ((P & 1) << 7));
FlagC = (temp8 & 1) != 0;
NZ_A();
}
}
void Imp_LSR_A()
{
FetchDummy();
FlagC = (A & 1) != 0;
A = (byte)(A >> 1);
NZ_A();
}
rdy_freeze = !RDY;
if (RDY)
{
FetchDummy();
FlagC = (A & 1) != 0;
A = (byte)(A >> 1);
NZ_A();
}
}
void JMP_abs()
{
rdy_freeze = !RDY;
@ -2082,8 +2111,6 @@ namespace BizHawk.Emulation.Cores.Components.M6502
void IncPC()
{
PC++;
}
void ZP_RMW_Stage3()
{
@ -2097,21 +2124,18 @@ namespace BizHawk.Emulation.Cores.Components.M6502
void ZP_RMW_Stage5()
{
WriteMemory(opcode2, (byte)alu_temp);
}
void ZP_RMW_INC()
{
WriteMemory(opcode2, (byte)alu_temp);
alu_temp = (byte)((alu_temp + 1) & 0xFF);
P = (byte)((P & 0x7D) | TableNZ[alu_temp]);
}
void ZP_RMW_DEC()
{
WriteMemory(opcode2, (byte)alu_temp);
alu_temp = (byte)((alu_temp - 1) & 0xFF);
P = (byte)((P & 0x7D) | TableNZ[alu_temp]);
}
void ZP_RMW_ASL()
{
@ -2120,7 +2144,6 @@ namespace BizHawk.Emulation.Cores.Components.M6502
FlagC = (value8 & 0x80) != 0;
alu_temp = value8 = (byte)(value8 << 1);
P = (byte)((P & 0x7D) | TableNZ[value8]);
}
void ZP_RMW_SRE()
{
@ -2163,7 +2186,6 @@ namespace BizHawk.Emulation.Cores.Components.M6502
alu_temp = value8 = (byte)((value8 >> 1) | ((P & 1) << 7));
FlagC = (temp8 & 1) != 0;
P = (byte)((P & 0x7D) | TableNZ[value8]);
}
void ZP_RMW_ROL()
{
@ -2172,7 +2194,6 @@ namespace BizHawk.Emulation.Cores.Components.M6502
alu_temp = value8 = (byte)((value8 << 1) | (P & 1));
FlagC = (temp8 & 0x80) != 0;
P = (byte)((P & 0x7D) | TableNZ[value8]);
}
void ZP_RMW_SLO()
{
@ -2198,7 +2219,6 @@ namespace BizHawk.Emulation.Cores.Components.M6502
FlagC = (temp8 & 0x80) != 0;
A &= value8;
NZ_A();
}
void AbsIdx_Stage3_Y()
{