def test_indirect_indexed_y_page_boundary():
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.y_index = 0x3
AddressingModes.cycle_count = 0
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xB1 0x2a memory at 0x2a = [0xfe, 0x40]
mock_memory_controller.read.side_effect = [0x2a, 0xfe, 0x40]
# 'LDA' 0xB9 opcode uses indirect addressing
value = addressing_modes.handle(0xB1, registers,
mock_memory_controller)
assert mock_memory_controller.read.call_count == 3
assert mock_memory_controller.read.call_args_list[
0] == unittest.mock.call(1)
assert mock_memory_controller.read.call_args_list[
1] == unittest.mock.call(0x2a)
assert mock_memory_controller.read.call_args_list[
2] == unittest.mock.call(0x2b)
assert registers.pc == 2
assert value == 0x4101
assert AddressingModes.cycle_count == 1
def test_indirect():
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.y_index = 0xff
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0x6C 0x03 0xf0 and value at [0xf003] = 0x1234
mock_memory_controller.read.side_effect = [3, 0xf0, 0x34, 0x12]
# 'JMP' 0x6C opcode uses indirect addressing
value = addressing_modes.handle(0x6C, registers,
mock_memory_controller)
assert mock_memory_controller.read.call_count == 4
assert mock_memory_controller.read.call_args_list[
0] == unittest.mock.call(1)
assert mock_memory_controller.read.call_args_list[
1] == unittest.mock.call(2)
assert mock_memory_controller.read.call_args_list[
2] == unittest.mock.call(0xf003)
assert mock_memory_controller.read.call_args_list[
3] == unittest.mock.call(0xf004)
assert registers.pc == 3
assert value == 0x1234
def test_implied_has_no_effect(self):
addressing_modes = AddressingModes()
registers = Registers()
with patch.object(MemoryController, 'read', return_value = None) as mock_memory_controller:
# 'RTS' opcode is implied address mode
count = addressing_modes.handle(0x60, registers, mock_memory_controller)
self.assertEqual(count, None)
mock_memory_controller.assert_not_called()
self.assertTrue(registers == Registers())
def test_relative_loads_next_value_from_pc(self):
addressing_modes = AddressingModes()
registers = Registers()
with patch.object(MemoryController, 'read') as mock_memory_controller:
mock_memory_controller.read.return_value = 0x22
# 'BPL' 0x10 opcode is relative address mode
value = addressing_modes.handle(0x10, registers, mock_memory_controller)
mock_memory_controller.read.assert_called_with(0)
self.assertEqual(registers.pc, 1)
self.assertEqual(value, 0x22)
def test_implied_has_no_effect():
addressing_modes = AddressingModes()
registers = Registers()
with patch.object(MemoryController, 'read',
return_value=None) as mock_memory_controller:
# 'RTS' opcode is implied address mode
count = addressing_modes.handle(0x60, registers,
mock_memory_controller)
assert count == None
mock_memory_controller.assert_not_called()
assert registers == Registers()
def test_relative_loads_next_value_from_pc():
addressing_modes = AddressingModes()
registers = Registers()
with patch.object(MemoryController, 'read') as mock_memory_controller:
mock_memory_controller.read.return_value = 0x22
# 'BPL' 0x10 opcode is relative address mode
value = addressing_modes.handle(0x10, registers,
mock_memory_controller)
mock_memory_controller.read.assert_called_with(0)
assert registers.pc == 1
assert value == 0x22
def test_absolute_jmp_calls_read_correctly(self):
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xa5 0x22 and value at [0x0022] = 1
mock_memory_controller.read.side_effect = [0x22, 0x23, 1]
# 'JMP' 0x4c opcode is absolute address mode
value = addressing_modes.handle(0x4C, registers, mock_memory_controller)
self.assertEqual(mock_memory_controller.read.call_count, 2)
self.assertEqual(mock_memory_controller.read.call_args_list[0], unittest.mock.call(1))
self.assertEqual(mock_memory_controller.read.call_args_list[1], unittest.mock.call(2))
self.assertEqual(registers.pc, 3)
self.assertEqual(value, 0x2322)
def test_zero_page_calls_read_correctly(self):
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xa5 0x22 and value at [0x0022] = 1
mock_memory_controller.read.side_effect = [0x22, 1]
# 'LDA' 0xA5 opcode is zero page address mode
value = addressing_modes.handle(0xA5, registers, mock_memory_controller)
self.assertEqual(mock_memory_controller.read.call_count, 2)
self.assertEqual(mock_memory_controller.read.call_args_list[1], unittest.mock.call(0x22))
self.assertEqual(mock_memory_controller.read.call_args_list[0], unittest.mock.call(1))
self.assertEqual(registers.pc, 2)
self.assertEqual(value, 1)
def test_zero_page_y_index_deals_with_wraparound(self):
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.y_index = 0xff
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xB6 0x03 and value at [0x02] = 1
mock_memory_controller.read.side_effect = [3, 1]
# 'LDX 0xB6 opcode is zero page x indexed address mode
value = addressing_modes.handle(0xB6, registers, mock_memory_controller)
self.assertEqual(mock_memory_controller.read.call_count, 2)
self.assertEqual(mock_memory_controller.read.call_args_list[0], unittest.mock.call(1))
self.assertEqual(mock_memory_controller.read.call_args_list[1], unittest.mock.call(2))
self.assertEqual(registers.pc, 2)
self.assertEqual(value, 1)
def test_zp_index_indirect_x_wraparound_2(self):
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.x_index = 0xfe
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xA1 0x03 and value at [0xff] = 0x12, [0x00] = 0x34
mock_memory_controller.read.side_effect = [1, 0x34, 0x12]
# 'LDA' 0xA1 opcode uses indirect addressing
value = addressing_modes.handle(0xA1, registers, mock_memory_controller)
self.assertEqual(mock_memory_controller.read.call_count, 3)
self.assertEqual(mock_memory_controller.read.call_args_list[0], unittest.mock.call(1))
self.assertEqual(mock_memory_controller.read.call_args_list[1], unittest.mock.call(0xff))
self.assertEqual(mock_memory_controller.read.call_args_list[2], unittest.mock.call(0))
self.assertEqual(registers.pc, 2)
self.assertEqual(value, 0x1234)
def test_absolute_y_page_boundary(self):
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.y_index = 0x3
AddressingModes.cycle_count = 0
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xB9 0xc000
mock_memory_controller.read.side_effect = [0xfe, 0xc0]
# 'LDA' 0xB9 opcode uses indirect addressing
value = addressing_modes.handle(0xB9, registers, mock_memory_controller)
self.assertEqual(mock_memory_controller.read.call_count, 2)
self.assertEqual(mock_memory_controller.read.call_args_list[0], unittest.mock.call(1))
self.assertEqual(mock_memory_controller.read.call_args_list[1], unittest.mock.call(2))
self.assertEqual(registers.pc, 3)
self.assertEqual(value, 0xc101)
self.assertEqual(AddressingModes.cycle_count, 1)
def test_indirect(self):
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.y_index = 0xff
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0x6C 0x03 0xf0 and value at [0xf003] = 0x1234
mock_memory_controller.read.side_effect = [3, 0xf0, 0x34, 0x12]
# 'JMP' 0x6C opcode uses indirect addressing
value = addressing_modes.handle(0x6C, registers, mock_memory_controller)
self.assertEqual(mock_memory_controller.read.call_count, 4)
self.assertEqual(mock_memory_controller.read.call_args_list[0], unittest.mock.call(1))
self.assertEqual(mock_memory_controller.read.call_args_list[1], unittest.mock.call(2))
self.assertEqual(mock_memory_controller.read.call_args_list[2], unittest.mock.call(0xf003))
self.assertEqual(mock_memory_controller.read.call_args_list[3], unittest.mock.call(0xf004))
self.assertEqual(registers.pc, 3)
self.assertEqual(value, 0x1234)
def test_zero_page_calls_read_correctly():
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xa5 0x22 and value at [0x0022] = 1
mock_memory_controller.read.side_effect = [0x22, 1]
# 'LDA' 0xA5 opcode is zero page address mode
value = addressing_modes.handle(0xA5, registers,
mock_memory_controller)
assert mock_memory_controller.read.call_count == 2
assert mock_memory_controller.read.call_args_list[
1] == unittest.mock.call(0x22)
assert mock_memory_controller.read.call_args_list[
0] == unittest.mock.call(1)
assert registers.pc == 2
assert value == 1
def test_absolute_jmp_calls_read_correctly():
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xa5 0x22 and value at [0x0022] = 1
mock_memory_controller.read.side_effect = [0x22, 0x23, 1]
# 'JMP' 0x4c opcode is absolute address mode
value = addressing_modes.handle(0x4C, registers,
mock_memory_controller)
assert mock_memory_controller.read.call_count == 2
assert mock_memory_controller.read.call_args_list[
0] == unittest.mock.call(1)
assert mock_memory_controller.read.call_args_list[
1] == unittest.mock.call(2)
assert registers.pc == 3
assert value == 0x2322
def test_zero_page_y_index_deals_with_wraparound():
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.y_index = 0xff
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xB6 0x03 and value at [0x02] = 1
mock_memory_controller.read.side_effect = [3, 1]
# 'LDX 0xB6 opcode is zero page x indexed address mode
value = addressing_modes.handle(0xB6, registers,
mock_memory_controller)
assert mock_memory_controller.read.call_count == 2
assert mock_memory_controller.read.call_args_list[
0] == unittest.mock.call(1)
assert mock_memory_controller.read.call_args_list[
1] == unittest.mock.call(2)
assert registers.pc == 2
assert value == 1
def test_indirect_indexed_y_zp_boundary(self):
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.y_index = 0x3
AddressingModes.cycle_count = 0
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xB1 0xff memory at 0xff = [0x28, 0x40]
mock_memory_controller.read.side_effect = [0xff, 0x28, 0x40]
# 'LDA' 0xB9 opcode uses indirect addressing
value = addressing_modes.handle(0xB1, registers, mock_memory_controller)
self.assertEqual(mock_memory_controller.read.call_count, 3)
self.assertEqual(mock_memory_controller.read.call_args_list[0], unittest.mock.call(1))
self.assertEqual(mock_memory_controller.read.call_args_list[1], unittest.mock.call(0xff))
self.assertEqual(mock_memory_controller.read.call_args_list[2], unittest.mock.call(0x00))
self.assertEqual(registers.pc, 2)
self.assertEqual(value, 0x402b)
self.assertEqual(AddressingModes.cycle_count, 0)
def test_zp_index_indirect_x_wraparound_2():
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.x_index = 0xfe
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xA1 0x03 and value at [0xff] = 0x12, [0x00] = 0x34
mock_memory_controller.read.side_effect = [1, 0x34, 0x12]
# 'LDA' 0xA1 opcode uses indirect addressing
value = addressing_modes.handle(0xA1, registers,
mock_memory_controller)
assert mock_memory_controller.read.call_count == 3
assert mock_memory_controller.read.call_args_list[
0] == unittest.mock.call(1)
assert mock_memory_controller.read.call_args_list[
1] == unittest.mock.call(0xff)
assert mock_memory_controller.read.call_args_list[
2] == unittest.mock.call(0)
assert registers.pc == 2
assert value == 0x1234
def test_absolute_y():
addressing_modes = AddressingModes()
registers = Registers()
registers.pc = 1 #fake loading of opcode
registers.y_index = 0x3
AddressingModes.cycle_count = 0
with patch.object(MemoryController, 'read') as mock_memory_controller:
# we're mocking 0xB9 0xc000
mock_memory_controller.read.side_effect = [0, 0xc0]
# 'LDA' 0xB9 opcode uses indirect addressing
value = addressing_modes.handle(0xB9, registers,
mock_memory_controller)
assert mock_memory_controller.read.call_count == 2
assert mock_memory_controller.read.call_args_list[
0] == unittest.mock.call(1)
assert mock_memory_controller.read.call_args_list[
1] == unittest.mock.call(2)
assert registers.pc == 3
assert value == 0xc003
assert AddressingModes.cycle_count == 0