class TestSystemFunctionOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory()
self.cpu = CPU(self.memory)
def test_BRK(self):
self.cpu.program_counter = 0x1000
self.memory.rom.load(0xFFFE, [0x00, 0x20])
status = self.cpu.status_as_byte()
self.cpu.BRK()
self.assertEqual(self.cpu.program_counter, 0x2000)
self.assertEqual(self.cpu.break_flag, 1)
self.assertEqual(self.memory.read_byte(self.cpu.STACK_PAGE + self.cpu.stack_pointer + 1), status)
self.assertEqual(self.memory.read_byte(self.cpu.STACK_PAGE + self.cpu.stack_pointer + 2), 0x01)
self.assertEqual(self.memory.read_byte(self.cpu.STACK_PAGE + self.cpu.stack_pointer + 3), 0x10)
def test_RTI(self):
self.memory.write_byte(self.cpu.STACK_PAGE + 0xFF, 0x12)
self.memory.write_byte(self.cpu.STACK_PAGE + 0xFE, 0x33)
self.memory.write_byte(self.cpu.STACK_PAGE + 0xFD, 0x20)
self.cpu.stack_pointer = 0xFC
self.cpu.RTI()
self.assertEqual(self.cpu.program_counter, 0x1233)
self.assertEqual(self.cpu.status_as_byte(), 0x20)
def test_NOP(self):
self.cpu.NOP()
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)
class Test6502Bugs(unittest.TestCase):
def setUp(self):
self.memory = Memory()
self.cpu = CPU(self.memory)
def test_zero_page_x(self):
self.cpu.x_index = 0x01
self.memory.load(0x1000, [0x00, 0x7F, 0xFF])
self.cpu.program_counter = 0x1000
self.assertEqual(self.cpu.zero_page_x_mode(), 0x01)
self.assertEqual(self.cpu.zero_page_x_mode(), 0x80)
self.assertEqual(self.cpu.zero_page_x_mode(), 0x00)
def test_indirect(self):
self.memory.load(0x20, [0x00, 0x20])
self.memory.load(0x00, [0x12])
self.memory.load(0xFF, [0x34])
self.memory.load(0x100, [0x56])
self.memory.load(0x1000, [0x20, 0x20, 0xFF, 0xFF, 0x00, 0x45, 0x23])
self.memory.load(0x2000, [0x05])
self.memory.load(0x1234, [0x05])
self.memory.load(0x2345, [0x00, 0xF0])
self.cpu.program_counter = 0x1000
self.cpu.x_index = 0x00
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.y_index = 0x00
self.cpu.LDA(self.cpu.indirect_y_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.y_index = 0x00
self.cpu.LDA(self.cpu.indirect_y_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.x_index = 0x00
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.x_index = 0xFF
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.assertEqual(self.cpu.indirect_mode(), 0xF000)
def setUp(self):
self.memory = Memory()
self.cpu = CPU(self.memory)
