def setup(self):
"""Init state."""
self.ram = create_autospec(RandomAccessMemory, True, True)
self.registers = create_autospec(RegisterMemory, True, True)
self.alu = create_autospec(ArithmeticLogicUnit, True, True)
self.control_unit = AbstractControlUnit(self.registers,
self.ram,
self.alu,
WORD_SIZE)
assert self.control_unit.operand_size == WORD_SIZE
class TestAbstractControlUnit:
"""Test case for abstract control unit."""
ram = None
registers = None
alu = None
control_unit = None
def setup(self):
"""Init state."""
self.ram = create_autospec(RandomAccessMemory, True, True)
self.registers = create_autospec(RegisterMemory, True, True)
self.alu = create_autospec(ArithmeticLogicUnit, True, True)
self.control_unit = AbstractControlUnit(self.registers,
self.ram,
self.alu,
WORD_SIZE)
assert self.control_unit.operand_size == WORD_SIZE
def test_get_status(self):
"""Test halt interaction between ALU and CU."""
self.registers.fetch.return_value = 0
assert self.control_unit.get_status() == RUNNING
self.registers.fetch.return_value = HALT
assert self.control_unit.get_status() == HALTED
def test_abstract_methods(self):
"""Abstract class."""
with raises(NotImplementedError):
self.control_unit.fetch_and_decode()
with raises(NotImplementedError):
self.control_unit.load()
with raises(NotImplementedError):
self.control_unit.execute()
with raises(NotImplementedError):
self.control_unit.write_back()
def test_step_and_run(self):
"""Test command execution."""
def do_nothing():
"""Empty function."""
self.control_unit.fetch_and_decode = create_autospec(do_nothing)
self.control_unit.load = create_autospec(do_nothing)
self.control_unit.execute = create_autospec(do_nothing)
self.control_unit.write_back = create_autospec(do_nothing)
self.control_unit.step()
self.control_unit.fetch_and_decode.assert_called_once_with()
self.control_unit.load.assert_called_once_with()
self.control_unit.execute.assert_called_once_with()
self.control_unit.write_back.assert_called_once_with()
self.control_unit.get_status = create_autospec(do_nothing)
self.control_unit.get_status.return_value = HALTED
self.control_unit.run()
self.control_unit.get_status.assert_called_with()
self.control_unit.fetch_and_decode.assert_called_once_with()
self.control_unit.load.assert_called_once_with()
self.control_unit.execute.assert_called_once_with()
self.control_unit.write_back.assert_called_once_with()