public void Execute_WhenFlagTrue_ShouldSetProgramCounterToValue()
{
ushort expectedProgramCounter = 0x3141;
FlagsMock.SetupGet(f => f.LessThan).Returns(true);
var sut = CreateSut(expectedProgramCounter);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(reg => reg.ProgramCounter = expectedProgramCounter);
}
public void Execute_WhenFlagFalse_ShouldNotSetProgramCounter()
{
ushort expectedProgramCounter = 0x3141;
FlagsMock.SetupGet(f => f.Equal).Returns(false);
var sut = CreateSut(expectedProgramCounter);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(reg => reg.ProgramCounter = expectedProgramCounter, Times.Never);
}
public void Execute_WhenInvoked_ShouldStoreTheValueInMemory()
{
RegistersMock.SetupGet(r => r.StackPointer).Returns(0xFFFC);
MemoryMock.Setup(m => m.GetWord(0xFFFC)).Returns(1234);
var sut = CreateSut(3);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(r => r[3] = 1234);
}
public void Execute_WhenInvoked_ShouldAddTheConstantToTheRigister()
{
byte expectedRegister = 7;
ushort constValue = 0x3456;
ushort initialRegisterValue = 0x1234;
var sut = CreateSut(expectedRegister, constValue);
RegistersMock.SetupGet(r => r[expectedRegister]).Returns(initialRegisterValue);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(reg => reg[expectedRegister] = (ushort)(constValue + initialRegisterValue));
}
public void Execute_WhenInvoked_ShouldStoreTheValueInTheRegister()
{
// LD R4, R2
byte targetRegister = 4;
byte sourceRegister = 2;
ushort expectedValue = 0x3456;
RegistersMock.SetupGet(r => r[sourceRegister]).Returns(expectedValue);
var sut = CreateSut(targetRegister, sourceRegister);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(r => r[targetRegister] = expectedValue);
}
public void Execute_WhenCalled_ShouldSetProgramCounterToValueOnStack()
{
ushort expectedStackPointer = 0xFFFC;
ushort extepedReturnAddress = 0xA020;
RegistersMock.SetupGet(r => r.StackPointer).Returns(expectedStackPointer);
MemoryMock.Setup(mm => mm.GetWord(expectedStackPointer)).Returns(extepedReturnAddress);
var sut = CreateSut(expectedStackPointer);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(reg => reg.ProgramCounter = extepedReturnAddress);
RegistersMock.VerifySet(r => r.StackPointer = (ushort)(expectedStackPointer + 4));
}
public void Execute_WhenInvoked_ShouldStoreTheValueInTheRegister()
{
// LD R4, R2
byte targetRegister = 2;
ushort expectedValue = 0x3456;
ushort expectedAddress = 0x0034;
MemoryMock.Setup(m => m.GetWord(expectedAddress)).Returns(expectedValue);
var sut = CreateSut(targetRegister, expectedAddress);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(r => r[targetRegister] = expectedValue);
}
public void Execute_WhenInvoked_ShouldStoreTheValueInMemory()
{
byte targetRegister = 6;
ushort expectedValue = 0x3456;
ushort expectedStackPointer = 0xFFFF;
RegistersMock.SetupGet(r => r.StackPointer).Returns(expectedStackPointer);
RegistersMock.SetupGet(r => r[targetRegister]).Returns(expectedValue);
var sut = CreateSut(targetRegister);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(r => r.StackPointer = (ushort)(expectedStackPointer - 4), Times.Once());
MemoryMock.Verify(m => m.SetWord(It.IsAny <ushort>(), expectedValue));
}
public void Execute_WhenInvoked_ShouldStoreTheValueInMemory()
{
// LD R6, 0x3456
// STL R6, (0x2234)
byte targetRegister = 6;
ushort expectedValue = 0x3456;
ushort expectedAddress = 0x2234;
RegistersMock.SetupGet(r => r[targetRegister]).Returns(expectedValue);
var sut = CreateSut(targetRegister, expectedAddress);
sut.Execute(CpuMock.Object);
MemoryMock.VerifySet(m => m[expectedAddress] = LowByte(expectedValue));
}
public void Execute_WhenInvoked_ShouldSetFlagsCorrectly(int lvalue, int rvalue, bool eq, bool lt, bool gt)
{
// CMP r1, 0xNNNN
byte leftRegister = 1;
RegistersMock.SetupGet(r => r[leftRegister]).Returns((ushort)lvalue);
var sut = CreateSut(leftRegister, (ushort)rvalue);
sut.Execute(CpuMock.Object);
FlagsMock.VerifySet(f => f.Equal = eq);
FlagsMock.VerifySet(f => f.GreaterThan = gt);
FlagsMock.VerifySet(f => f.LessThan = lt);
}
public void Execute_WhenInvoked_ShouldAddTheConstantToTheRigister()
{
// SUB R7, R4
byte firstRegister = 7;
byte secondRegister = 4;
ushort firstRegisterValue = 0x3456;
ushort secondRegisterValue = 0x1234;
RegistersMock.SetupGet(r => r[firstRegister]).Returns(firstRegisterValue);
RegistersMock.SetupGet(r => r[secondRegister]).Returns(secondRegisterValue);
var sut = CreateSut(firstRegister, secondRegister);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(reg => reg[firstRegister] = (ushort)(firstRegisterValue - secondRegisterValue));
}
public void Execute_WhenInvoked_ShouldSetProgramCounterToValueAndPushReturnAddress()
{
ushort stackPointer = 0xFFFC;
ushort callAddress = 0x3141;
ushort currentProgramCounter = 0x00F0;
var decrementedStackPointer = (ushort)(stackPointer - 4);
RegistersMock.SetupGet(r => r.StackPointer).Returns(stackPointer);
RegistersMock.SetupGet(r => r.ProgramCounter).Returns(currentProgramCounter);
var sut = CreateSut(callAddress);
sut.Execute(CpuMock.Object);
RegistersMock.VerifySet(r => r.StackPointer = decrementedStackPointer);
// since its a mock the pre-decrement isn't real, so ignore the address
MemoryMock.Verify(m => m.SetWord(It.IsAny <ushort>(), currentProgramCounter));
RegistersMock.VerifySet(r => r.ProgramCounter = callAddress);
}
public void Execute_WhenInvoked_ShouldStoreTheValueInMemory()
{
// LD R3, 0x2234
// LD R6, 0x3456
// ST R6, (R3)
byte targetRegister = 6;
byte expectedAddressRegister = 3;
ushort expectedValue = 0x3456;
ushort expectedAddress = 0x2234;
RegistersMock.SetupGet(r => r[targetRegister]).Returns(expectedValue);
RegistersMock.SetupGet(r => r[expectedAddressRegister]).Returns(expectedAddress);
var sut = CreateSut(targetRegister, expectedAddressRegister);
sut.Execute(CpuMock.Object);
MemoryMock.Verify(m => m.SetWord(expectedAddress, expectedValue));
}
