public void ADC_Can_Add_Negative_One_Plus_Negative_2()
{
var test = new TestSpec
{
C = false,
A = 0xff, // -1
OpCode = OpCodeId.ADC_I,
FinalValue = 0xfe, // -2
ExpectedA = 0xfd, // -3
};
test.Execute_And_Verify(AddrMode.I);
}
public void DEC_ZP_Sets_Negative_Flag_If_Result_Is_Negative()
{
var test = new TestSpec()
{
InsEffect = InstrEffect.Mem,
OpCode = OpCodeId.DEC_ZP,
FinalValue = 0x00,
ExpectedMemVal = 0xff,
ExpectedN = true,
};
test.Execute_And_Verify(AddrMode.ZP);
}
public void LDX_ZP_Y_Works()
{
var test = new TestSpec()
{
X = 0x00,
OpCode = OpCodeId.LDX_ZP_Y,
FinalValue = 0x12,
ExpectedX = 0x12,
ExpectedCycles = 4
};
test.Execute_And_Verify(AddrMode.ZP_Y);
}
public void SBC_I_Two_Small_Signed_Numbers_With_Different_Signs()
{
var test = new TestSpec
{
C = true,
A = 0x02,
OpCode = OpCodeId.SBC_I,
FinalValue = 0xff, // -1
ExpectedA = 0x03,
};
test.Execute_And_Verify(AddrMode.I);
}
public void DEC_ABS_X_Works()
{
var test = new TestSpec()
{
InsEffect = InstrEffect.Mem,
OpCode = OpCodeId.DEC_ABS_X,
FinalValue = 0x02,
ExpectedMemVal = 0x01,
ExpectedCycles = 7,
};
test.Execute_And_Verify(AddrMode.ABS_X);
}
public void SBC_I_Result_Is_Greater_Than_Zero_Will_Get_Zero_Flag_Clear()
{
var test = new TestSpec
{
C = true,
A = 0x00,
OpCode = OpCodeId.SBC_I,
FinalValue = 0xff, // -1
ExpectedZ = false,
};
test.Execute_And_Verify(AddrMode.I);
}
public void SBC_I_With_Two_Positive_Signed_Values_Resulting_In_A_Positive_Value_Will_Clear_Overflow_Flag()
{
var test = new TestSpec
{
C = true,
A = 0x02, // 2
OpCode = OpCodeId.SBC_I,
FinalValue = 0x01, // 1
ExpectedV = false,
};
test.Execute_And_Verify(AddrMode.I);
}
public void BNE_I_Jumps_To_Correct_Location_When_Offset_Is_Positive()
{
var test = new TestSpec()
{
PC = 0x2000,
Z = false, // BNE branches if Zero flag is clear.
OpCode = OpCodeId.BNE,
FinalValue = 0x20,
ExpectedPC = 0x2000 + 0x02 + 0x20, // The relative branch location should be where the PC is after the branching instruction has updated the PC (reading instruction + operand)
};
test.Execute_And_Verify(AddrMode.Relative);
}
public void BNE_I_Takes_2_Cycles_If_Branch_Fails()
{
var test = new TestSpec()
{
PC = 0x2000,
Z = true, // BNE does not branch if Zero flag is set.
OpCode = OpCodeId.BNE,
FinalValue = 0x20,
ExpectedCycles = 2
};
test.Execute_And_Verify(AddrMode.Relative);
}
public void BNE_I_Takes_4_Cycles_If_Page_Boundary_Is_Crossed()
{
var test = new TestSpec()
{
PC = 0x20f0,
Z = false, // BNE branches if Zero flag is clear.
OpCode = OpCodeId.BNE,
FinalValue = 0x20,
ExpectedCycles = 4,
};
test.Execute_And_Verify(AddrMode.Relative);
}
public void BNE_I_Does_Not_Jump_To_New_Location_If_Branch_Fails()
{
var test = new TestSpec()
{
PC = 0x2000,
Z = true, // BNE does not branch if Zero flag is set.
OpCode = OpCodeId.BNE,
FinalValue = 0x20,
ExpectedPC = 0x2000 + 0x02 // When branhing fails, the PC should remain unchanged and point to next instruction after this one
};
test.Execute_And_Verify(AddrMode.Relative);
}
public void BNE_I_Takes_3_Cycles_Within_Same_Page()
{
var test = new TestSpec()
{
PC = 0x2000,
Z = false, // BNE branches if Zero flag is clear.
OpCode = OpCodeId.BNE,
FinalValue = 0x20,
ExpectedCycles = 3
};
test.Execute_And_Verify(AddrMode.Relative);
}
public void TXS_Does_Not_Affect_Status_Flags()
{
var test = new TestSpec()
{
PS = 0xff,
X = 0x34,
SP = 0x80,
OpCode = OpCodeId.TXS,
ExpectedPS = 0xff
};
test.Execute_And_Verify(AddrMode.Implied);
}
public void ADC_Sets_Zero_Flag_If_Result_Is_Zero()
{
var test = new TestSpec
{
C = false,
A = 0x00,
OpCode = OpCodeId.ADC_I,
FinalValue = 0x00,
ExpectedZ = true,
};
test.Execute_And_Verify(AddrMode.I);
}
public void TXA_Clears_Negative_Flag_If_Result_Is_Positive()
{
var test = new TestSpec()
{
X = 0x01,
A = 0x34,
OpCode = OpCodeId.TXA,
ExpectedN = false,
ExpectedA = 0x01,
};
test.Execute_And_Verify(AddrMode.Implied);
}
public void BNE_I_Jumps_To_Correct_Location_When_Offset_Is_Negative()
{
var test = new TestSpec()
{
PC = 0x2010,
Z = false, // BNE branches if Zero flag is clear.
OpCode = OpCodeId.BNE,
FinalValue = 0xf0, // - 10
ExpectedPC = 0x2010 + 0x02 - 0x10,
};
test.Execute_And_Verify(AddrMode.Relative);
}
public void SBC_I_Two_Small_Signed_Negative_Numbers()
{
var test = new TestSpec
{
C = true,
A = 0xff, // -1
OpCode = OpCodeId.SBC_I,
FinalValue = 0xfe, // -2
ExpectedA = 0x01,
};
test.Execute_And_Verify(AddrMode.I);
}
public void BNE_I_Jumps_To_Correct_Location_When_Offset_Crosses_Page_Boundary()
{
var test = new TestSpec()
{
PC = 0x20f0,
Z = false, // BNE branches if Zero flag is clear.
OpCode = OpCodeId.BNE,
FinalValue = 0x20, // + 20
ExpectedPC = 0x20f0 + 0x02 + 0x20,
};
test.Execute_And_Verify(AddrMode.Relative);
}
public void SBC_I_Result_Is_Has_Bit_7_Set_Will_Get_Negative_Flag_Set()
{
var test = new TestSpec
{
C = true,
A = 0x00,
OpCode = OpCodeId.SBC_I,
FinalValue = 0x01,
ExpectedN = true,
};
test.Execute_And_Verify(AddrMode.I);
}
public void TAY_ZP_Sets_Zero_Flag_If_Result_Is_Zero()
{
var test = new TestSpec()
{
A = 0x00,
Y = 0x01,
OpCode = OpCodeId.TAY,
ExpectedZ = true,
ExpectedY = 0x00,
};
test.Execute_And_Verify(AddrMode.Implied);
}
public void SBC_I_Two_Small_Unsigned_Numbers()
{
var test = new TestSpec
{
C = true, // Carry must be set before SBC to perform a subtraction without borrow.
A = 0x03,
OpCode = OpCodeId.SBC_I,
FinalValue = 0x01,
ExpectedA = 0x02,
};
test.Execute_And_Verify(AddrMode.I);
}
public void TAY_ZP_Clears_Zero_Flag_If_Result_Is_Not_Zero()
{
var test = new TestSpec()
{
A = 0x34,
Y = 0x01,
OpCode = OpCodeId.TAY,
ExpectedZ = false,
ExpectedY = 0x34,
};
test.Execute_And_Verify(AddrMode.Implied);
}
public void DEC_ZP_X_Where_ZeroPage_Address_Plus_X_Wraps_Over_Byte_Size_Works()
{
var test = new TestSpec()
{
InsEffect = InstrEffect.Mem,
OpCode = OpCodeId.DEC_ZP_X,
FinalValue = 0x02,
ExpectedMemVal = 0x01,
ExpectedCycles = 6,
};
test.Execute_And_Verify(AddrMode.ZP_X, ZP_X_Should_Wrap_Over_Byte: true);
}
public void TAY_ZP_Sets_Negative_Flag_If_Result_Is_Negative()
{
var test = new TestSpec()
{
A = 0xfe,
Y = 0x00,
OpCode = OpCodeId.TAY,
ExpectedN = true,
ExpectedY = 0xfe,
};
test.Execute_And_Verify(AddrMode.Implied);
}
public void DEC_ZP_Decreases_Value_At_Memory_Location()
{
var test = new TestSpec()
{
InsEffect = InstrEffect.Mem,
OpCode = OpCodeId.DEC_ZP,
FinalValue = 0x02, // Will get written to the memory location being changed before instruction runs. Default address is used if not specified in ZeroPageAddress
//ZeroPageAddress = 0x20 // Optional. Will use a default ZeroPage address for test if not set
ExpectedMemVal = 0x01,
};
test.Execute_And_Verify(AddrMode.ZP);
}
public void TXA_Sets_Zero_Flag_If_Result_Is_Zero()
{
var test = new TestSpec()
{
X = 0x00,
A = 0x34,
OpCode = OpCodeId.TXA,
ExpectedZ = true,
ExpectedA = 0x00,
};
test.Execute_And_Verify(AddrMode.Implied);
}
public void DEC_ZP_Clears_Negative_Flag_If_Result_Is_Positive()
{
var test = new TestSpec()
{
InsEffect = InstrEffect.Mem,
OpCode = OpCodeId.DEC_ZP,
FinalValue = 0x02,
ExpectedMemVal = 0x01,
ExpectedN = false,
};
test.Execute_And_Verify(AddrMode.ZP);
}
public void TXA_Sets_Negative_Flag_If_Result_Is_Negative()
{
var test = new TestSpec()
{
X = 0xfe,
A = 0x34,
OpCode = OpCodeId.TXA,
ExpectedN = true,
ExpectedA = 0xfe,
};
test.Execute_And_Verify(AddrMode.Implied);
}
public void LDX_ZP_Y_Where_ZeroPage_Address_Plus_Y_Wraps_Over_Byte_Size_Works()
{
var test = new TestSpec()
{
X = 0x00,
OpCode = OpCodeId.LDX_ZP_Y,
FinalValue = 0x12,
ExpectedX = 0x12,
ExpectedCycles = 4
};
test.Execute_And_Verify(AddrMode.ZP_Y, ZP_Y_Should_Wrap_Over_Byte: true);
}
public void ADC_Can_Add_2_Plus_Negative_1()
{
var test = new TestSpec
{
C = false,
A = 0x02,
OpCode = OpCodeId.ADC_I,
FinalValue = 0xff,
ExpectedA = 0x01,
};
test.Execute_And_Verify(AddrMode.I);
}