class TestStackOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory()
self.cpu = CPU(self.memory)
def test_TSX(self):
s = self.cpu.stack_pointer
self.cpu.TSX()
self.assertEqual(self.cpu.x_index, s)
# @@@ check NZ?
def test_TXS(self):
x = self.cpu.x_index
self.cpu.TXS()
self.assertEqual(self.cpu.stack_pointer, x)
def test_PHA_and_PLA(self):
self.cpu.accumulator = 0x00
self.cpu.PHA()
self.cpu.accumulator = 0x01
self.cpu.PHA()
self.cpu.accumulator = 0xFF
self.cpu.PHA()
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 1)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0x01)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.sign_flag, 0)
def test_PHP_and_PLP(self):
p = self.cpu.status_as_byte()
self.cpu.PHP()
self.cpu.status_from_byte(0xFF)
self.cpu.PLP()
self.assertEqual(self.cpu.status_as_byte(), p)
