public void TestStepNonMaskableInterrupt(bool initialIFF1, bool initialIFF2)
{
var initialState = new CPUConfig()
{
InterruptsEnabled = initialIFF1,
InterruptsEnabledPreviousValue = initialIFF2,
Registers = new CPURegisters()
{
PC = 0x1234,
SP = 0x3FFF,
},
};
var cpu = new CPU(initialState);
var cycles = cpu.StepNonMaskableInterrupt();
Assert.Equal(17, cycles);
// We should've jumped to 0x0066.
Assert.Equal(0x0066, cpu.Registers.PC);
// Interrupts should be disabled (IFF1).
Assert.False(cpu.InterruptsEnabled);
// The previous value of IFF1 should have been preserved in IFF2.
Assert.Equal(initialIFF1, cpu.InterruptsEnabledPreviousValue);
// Ensure the previous program counter value was pushed onto the stack.
Assert.Equal(0x3FFD, cpu.Registers.SP);
Assert.Equal(0x12, cpu.Memory.Read(0x3FFE));
Assert.Equal(0x34, cpu.Memory.Read(0x3FFD));
}
public void Test_LD_MRR_N_ToMemory()
{
var rom = AssembleSource($@"
org 00h
LD (HL), 42h
HALT
");
var registers = new CPURegisters();
registers[Register.H] = 0x22;
registers[Register.L] = 0x33;
var initialState = new CPUConfig()
{
Registers = registers,
};
var state = Execute(rom, initialState);
Assert.Equal(0x42, state.Memory[0x2233]);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 10, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_IN_A_MN_DoesNotThrowExceptionIfNoHandlersPresent()
{
var rom = AssembleSource($@"
org 00h
IN A, (2)
HALT
");
var initialState = new CPUConfig();
initialState.Registers = new CPURegisters()
{
A = 0x11,
};
var cpu = new CPU(initialState);
var state = Execute(rom, cpu);
Assert.Equal(0x00, state.Registers.A);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 10, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_INC_MIY_NoFlags(int offset)
{
var rom = AssembleSource($@"
org 00h
INC (IY {(offset < 0 ? '-' : '+')} {Math.Abs(offset)})
HALT
");
var registers = new CPURegisters()
{
IY = 0x2477,
};
var memory = new byte[16384];
memory[0x2477 + offset] = 0x42;
var initialState = new CPUConfig()
{
Registers = registers, Flags = new ConditionFlags()
{
Subtract = true,
},
};
var state = Execute(rom, memory, initialState);
Assert.Equal(0x43, state.Memory[0x2477 + offset]);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 23, state.Cycles);
Assert.Equal(0x03, state.Registers.PC);
}
public void Test_ADD_A_N_OverflowFlag()
{
var rom = AssembleSource($@"
org 00h
ADD A, 2
HALT
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
A = 127,
},
};
var state = Execute(rom, initialState);
Assert.Equal(129, state.Registers.A);
Assert.True(state.Flags.Sign);
Assert.False(state.Flags.Zero);
Assert.True(state.Flags.HalfCarry);
Assert.True(state.Flags.ParityOverflow);
Assert.False(state.Flags.Subtract);
Assert.False(state.Flags.Carry);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 7, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_IN_R_MC_DoesNotThrowExceptionIfNoHandlersPresent()
{
var rom = AssembleSource($@"
org 00h
IN B, (C)
HALT
");
var initialState = new CPUConfig();
initialState.Registers = new CPURegisters();
initialState.Registers.C = 123;
initialState.Registers.B = 44;
var cpu = new CPU(initialState);
var state = Execute(rom, cpu);
Assert.Equal(0, state.Registers.B);
Assert.False(state.Flags.Sign);
Assert.True(state.Flags.Zero);
Assert.True(state.Flags.ParityOverflow);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 12, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_DJNZ()
{
var rom = AssembleSource($@"
org 00h
NOP ; $0000
NOP ; $0001
DJNZ $+5 ; $0002
NOP ; $0004
HALT ; $0005
HALT ; $0006
NOP ; $0007
JP $0002 ; $0008
HALT ; $0009
HALT ; $000A
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
B = 4,
},
};
var state = Execute(rom, initialState);
Assert.Equal(0x0000, state.Registers.SP);
AssertFlagsFalse(state);
Assert.Equal(14, state.Iterations);
Assert.Equal(4 + (4 * 6) + (13 * 3) + (10 * 3) + 8, state.Cycles);
Assert.Equal(0x0005, state.Registers.PC);
}
public void Test_JP_NC_Jumps()
{
var rom = AssembleSource($@"
org 00h
NOP ; $0000
NOP ; $0001
JP NC, 000Ah; $0002
HALT ; $0005
NOP ; $0006
NOP ; $0007
NOP ; $0008
NOP ; $0009
HALT ; $000A
");
var initialState = new CPUConfig()
{
Flags = new ConditionFlags()
{
Carry = false,
},
};
var state = Execute(rom, initialState);
Assert.Equal(0x0000, state.Registers.SP);
AssertFlagsSame(initialState, state);
Assert.Equal(4, state.Iterations);
Assert.Equal(4 + (4 * 2) + 10, state.Cycles);
Assert.Equal(0x000A, state.Registers.PC);
}
public void Test_LD_SP_HL()
{
var rom = AssembleSource($@"
org 00h
LD SP, HL
HALT
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
HL = 0x2477,
},
};
var state = Execute(rom, initialState);
AssertFlagsFalse(state);
Assert.Equal(0x2477, state.Registers.SP);
Assert.Equal(0x2477, state.Registers.HL);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 6, state.Cycles);
Assert.Equal(0x0001, state.Registers.PC);
}
public void Test_PUSH_IY()
{
var rom = AssembleSource($@"
org 00h
PUSH IY
HALT
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
SP = 0x3000,
IY = 0x2477,
},
};
var state = Execute(rom, initialState);
Assert.Equal(0x2477, state.Registers.IY);
Assert.Equal(0x00, state.Memory[0x3000]);
Assert.Equal(0x24, state.Memory[0x2FFF]);
Assert.Equal(0x77, state.Memory[0x2FFE]);
Assert.Equal(0x2FFE, state.Registers.SP);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 15, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void TestXCHG()
{
var rom = AssembleSource($@"
org 00h
EX DE, HL
HALT
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
H = 0x42,
D = 0x99,
L = 0x77,
E = 0x88,
},
};
var state = Execute(rom, initialState);
Assert.Equal(0x99, state.Registers.H);
Assert.Equal(0x42, state.Registers.D);
Assert.Equal(0x88, state.Registers.L);
Assert.Equal(0x77, state.Registers.E);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 4, state.Cycles);
Assert.Equal(0x01, state.Registers.PC);
}
public void Test_LD_HL_MNN()
{
var rom = AssembleSource($@"
org 00h
LD HL, (2477h)
HALT
");
var memory = new byte[16384];
memory[0x2477] = 0x77;
memory[0x2478] = 0x66;
var initialState = new CPUConfig()
{
};
var state = Execute(rom, memory, initialState);
Assert.Equal(0x66, state.Registers.H);
Assert.Equal(0x77, state.Registers.L);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 16, state.Cycles);
Assert.Equal(0x03, state.Registers.PC);
}
public void TestArithmeticAdditionSetsFlags(string valueA, string valueB, int expectedRegValue, int expectedRegSignedValue, ConditionFlags expected)
{
var rom = AssembleSource($@"
org 00h
LD A, {valueA}
LD B, {valueB}
ADD B
HALT
");
var initialState = new CPUConfig()
{
Flags = new ConditionFlags()
{
Sign = !expected.Sign,
Zero = !expected.Zero,
HalfCarry = !expected.HalfCarry,
ParityOverflow = !expected.ParityOverflow,
Subtract = !expected.Subtract,
Carry = !expected.Carry,
},
};
var state = Execute(rom, initialState);
Assert.Equal(expectedRegValue, state.Registers.A);
Assert.Equal(expectedRegSignedValue, (sbyte)state.Registers.A);
Assert.Equal(expected.Sign, state.Flags.Sign);
Assert.Equal(expected.Zero, state.Flags.Zero);
Assert.Equal(expected.HalfCarry, state.Flags.HalfCarry);
Assert.Equal(expected.ParityOverflow, state.Flags.ParityOverflow);
Assert.Equal(expected.Subtract, state.Flags.Subtract);
Assert.Equal(expected.Carry, state.Flags.Carry);
}
public void TestStepMaskableInterrupt_Mode1()
{
var initialState = new CPUConfig()
{
InterruptsEnabled = true,
InterruptMode = InterruptMode.One,
Registers = new CPURegisters()
{
PC = 0x1234,
SP = 0x3FFF,
},
};
var cpu = new CPU(initialState);
var cycles = cpu.StepMaskableInterrupt(0x00);
Assert.Equal(11, cycles);
// Interrupts should still be enabled (IFF1).
Assert.True(cpu.InterruptsEnabled);
// We should've jumped here.
Assert.Equal(0x0038, cpu.Registers.PC);
// Ensure the previous program counter value was pushed onto the stack.
Assert.Equal(0x3FFD, cpu.Registers.SP);
Assert.Equal(0x12, cpu.Memory.Read(0x3FFE));
Assert.Equal(0x34, cpu.Memory.Read(0x3FFD));
}
public void Test_LD_MNN_HL()
{
// We have to assemble by hand here since LD (**), HL is a duplicate instruction
// and the assembler will use the standard instruction instead of the undocumented
// extended instruction.
var rom = new byte[]
{
0xED, 0x63, // LD (NN), HL
0x77, 0x24, // (2477h)
0x76 // HALT
};
var memory = new byte[20490];
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
HL = 0x6677,
},
};
var state = Execute(rom, memory, initialState);
Assert.Equal(0x77, state.Memory[0x2477]);
Assert.Equal(0x66, state.Memory[0x2478]);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 20, state.Cycles);
Assert.Equal(0x04, state.Registers.PC);
}
public void Test_ADC_A_N_NoFlags()
{
var rom = AssembleSource($@"
org 00h
ADC A, 18h
HALT
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
A = 0x42,
},
Flags = new ConditionFlags()
{
Carry = true,
// Ensure this is flipped to zero because this was an addition.
Subtract = true,
},
};
var state = Execute(rom, initialState);
Assert.Equal(0x5B, state.Registers.A);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 7, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_LD_MNN_RR(RegisterPair registerPair)
{
var rom = AssembleSource($@"
org 00h
LD (2477h), {registerPair}
HALT
");
var memory = new byte[20490];
var initialState = new CPUConfig();
initialState.Registers[registerPair] = 0x6677;
var state = Execute(rom, memory, initialState);
Assert.Equal(0x77, state.Memory[0x2477]);
Assert.Equal(0x66, state.Memory[0x2478]);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 20, state.Cycles);
Assert.Equal(0x04, state.Registers.PC);
}
public void Test_DI()
{
var rom = AssembleSource($@"
org 00h
DI
HALT
");
var initialState = new CPUConfig()
{
InterruptsEnabled = true,
InterruptsEnabledPreviousValue = true,
};
var state = Execute(rom, initialState);
Assert.False(state.InterruptsEnabled);
Assert.False(state.InterruptsEnabledPreviousValue);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 4, state.Cycles);
Assert.Equal(0x01, state.Registers.PC);
}
public void Test_IN_R_MC_SetsFlags()
{
var rom = AssembleSource($@"
org 00h
IN (C)
HALT
");
var initialState = new CPUConfig();
initialState.Registers = new CPURegisters();
initialState.Registers.C = 77;
var cpu = new CPU(initialState);
var actualDeviceId = -1;
cpu.OnDeviceRead += (int deviceID) => {
actualDeviceId = deviceID;
return(213);
};
var state = Execute(rom, cpu);
Assert.Equal(77, state.Registers.C);
Assert.Equal(77, actualDeviceId);
Assert.True(state.Flags.Sign);
Assert.False(state.Flags.Zero);
Assert.False(state.Flags.ParityOverflow);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 12, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_OR_A_NoFlags()
{
var rom = AssembleSource($@"
org 00h
OR A
HALT
");
var registers = new CPURegisters();
registers.A = 0b01100100;
var initialState = new CPUConfig()
{
Registers = registers,
};
var state = Execute(rom, initialState);
Assert.Equal(0b01100100, state.Registers.A);
Assert.False(state.Flags.Sign);
Assert.False(state.Flags.Zero);
Assert.False(state.Flags.HalfCarry);
Assert.False(state.Flags.ParityOverflow);
Assert.False(state.Flags.Subtract);
Assert.False(state.Flags.Carry);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 4, state.Cycles);
Assert.Equal(0x01, state.Registers.PC);
}
public void Test_JP_HL()
{
var rom = AssembleSource($@"
org 00h
JP (HL) ; $0000
NOP ; $0001
NOP ; $0002
HALT ; $0003
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
HL = 0x003,
},
};
var state = Execute(rom, initialState);
AssertFlagsSame(initialState, state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 4, state.Cycles);
Assert.Equal(0x0003, state.Registers.PC);
}
public void Test_ADD_A_MIY_ExampleFromManual()
{
var rom = AssembleSource($@"
org 00h
ADD A, (IY + 5h)
HALT
");
var memory = new byte[16 * 1024];
memory[0x1005] = 0x22;
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
A = 0x11,
IY = 0x1000,
},
};
var state = Execute(rom, memory, initialState);
Assert.Equal(0x33, state.Registers.A);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 19, state.Cycles);
Assert.Equal(0x03, state.Registers.PC);
}
public void Test_EX_MSP_IY()
{
var rom = AssembleSource($@"
org 00h
EX (SP), IY
HALT
");
var memory = new byte[16384];
memory[0x2222] = 0x99;
memory[0x2223] = 0x88;
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
IY = 0x4277,
SP = 0x2222,
},
};
var state = Execute(rom, memory, initialState);
Assert.Equal(0x8899, state.Registers.IY);
Assert.Equal(0x77, state.Memory[0x2222]);
Assert.Equal(0x42, state.Memory[0x2223]);
Assert.Equal(0x2222, state.Registers.SP);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 23, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_IM(int modeNumber, InterruptMode mode)
{
var rom = AssembleSource($@"
org 00h
IM {modeNumber}
HALT
");
var initialState = new CPUConfig()
{
InterruptsEnabled = false,
InterruptsEnabledPreviousValue = false,
};
var cpu = new CPU(initialState);
var state = Execute(rom, cpu);
// Ensure the mode was set.
Assert.Equal(mode, cpu.InterruptMode);
// Setting mode does not enable interrupts.
Assert.False(cpu.InterruptsEnabled);
Assert.False(cpu.InterruptsEnabledPreviousValue);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 8, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_SUB_N_SignFlag()
{
var rom = AssembleSource($@"
org 00h
SUB 16h
HALT
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
A = 0xFF,
},
Flags = new ConditionFlags()
{
Subtract = false,
},
};
var state = Execute(rom, initialState);
Assert.Equal(0xE9, state.Registers.A);
Assert.True(state.Flags.Sign);
Assert.False(state.Flags.Zero);
Assert.False(state.Flags.HalfCarry);
Assert.False(state.Flags.ParityOverflow);
Assert.True(state.Flags.Subtract);
Assert.False(state.Flags.Carry);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 7, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
// [InlineData(Register.R, Register.A)] // TODO: Make specific tests for R register since it's special
// [InlineData(Register.A, Register.R)]
public void Test_LD(Register destReg, Register sourceReg)
{
var rom = AssembleSource($@"
org 00h
LD {destReg}, {sourceReg}
HALT
");
var initialState = new CPUConfig()
{
Registers = new CPURegisters()
{
[sourceReg] = 0x42,
[destReg] = 0x77,
},
};
var state = Execute(rom, initialState);
Assert.Equal(0x42, state.Registers[sourceReg]);
Assert.Equal(0x42, state.Registers[destReg]);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 9, state.Cycles);
Assert.Equal(0x02, state.Registers.PC);
}
public void Test_SCF_SetsFalseToTrue()
{
var rom = AssembleSource($@"
org 00h
SCF
HALT
");
var initialState = new CPUConfig()
{
Flags = new ConditionFlags()
{
Carry = false,
Subtract = true,
HalfCarry = true,
},
};
var state = Execute(rom, initialState);
Assert.False(state.Flags.Sign);
Assert.False(state.Flags.Zero);
Assert.False(state.Flags.HalfCarry);
Assert.False(state.Flags.ParityOverflow);
Assert.False(state.Flags.Subtract);
Assert.True(state.Flags.Carry);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 4, state.Cycles);
Assert.Equal(0x01, state.Registers.PC);
}
public void Test_LD_MNN_A()
{
var rom = AssembleSource($@"
org 00h
LD (2477h), A
HALT
");
var registers = new CPURegisters();
registers.A = 0x42;
var initialState = new CPUConfig()
{
Registers = registers,
};
var state = Execute(rom, initialState);
Assert.Equal(0x42, state.Memory[0x2477]);
Assert.Equal(0x42, state.Registers.A);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 13, state.Cycles);
Assert.Equal(0x03, state.Registers.PC);
}
public void Test_AND_ParityFlag(Register sourceReg)
{
var rom = AssembleSource($@"
org 00h
AND {sourceReg}
HALT
");
var registers = new CPURegisters();
registers.A = 0b11100101;
registers[sourceReg] = 0b00101110;
var initialState = new CPUConfig()
{
Registers = registers,
};
var state = Execute(rom, initialState);
Assert.Equal(0b00100100, state.Registers.A);
Assert.Equal(0b00101110, state.Registers[sourceReg]);
Assert.False(state.Flags.Sign);
Assert.False(state.Flags.Zero);
Assert.True(state.Flags.HalfCarry);
Assert.True(state.Flags.ParityOverflow);
Assert.False(state.Flags.Subtract);
Assert.False(state.Flags.Carry);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 4, state.Cycles);
Assert.Equal(0x01, state.Registers.PC);
}
public void Test_LD_A_MRR(RegisterPair registerPair)
{
var rom = AssembleSource($@"
org 00h
LD A, ({registerPair})
HALT
");
var registers = new CPURegisters();
registers[registerPair] = 0x2477;
var memory = new byte[16384];
memory[0x2477] = 0x42;
var initialState = new CPUConfig()
{
Registers = registers,
};
var state = Execute(rom, memory, initialState);
Assert.Equal(0x42, state.Memory[0x2477]);
Assert.Equal(0x42, state.Registers.A);
Assert.Equal(0x2477, state.Registers[registerPair]);
AssertFlagsFalse(state);
Assert.Equal(2, state.Iterations);
Assert.Equal(4 + 7, state.Cycles);
Assert.Equal(0x01, state.Registers.PC);
}