def PPUADDR_INC(self, value=1):
v = FlagByte(0x0)
v[0:8] = self._PPUADDR[0]
v[8:16] = self._PPUADDR[1]
v.value += value
self._PPUADDR[0] = v[0:8]
self._PPUADDR[1] = v[8:16]
def set_overflow(self, data):
data = FlagByte(data)
overflow = data[6]
self._registers.overflow = overflow
def set_negative(self, data):
data = FlagByte(data)
negative = data[7]
self._registers.negative = negative
def habdle_ins(self, ins, address, data):
if ins == 'JMP':
self._registers.PC = address
elif ins == 'BRK':
self._running = False
return
elif ins == 'LDX':
self._registers.X = data
self.set_zero_negative(data)
elif ins == 'STX':
self.write_address(address, self._registers.X)
elif ins == 'JSR':
pc = self._registers.PC - 1
self.push_stack(pc, hex_digit=True)
self._registers.PC = address
elif ins == 'SEC':
self._registers.carry = 1
elif ins == 'SEI':
self._registers.interrupt_disable = 1
elif ins == 'SED':
self._registers.decimal = 1
elif ins == 'BCS':
if self._registers.carry == 1:
self._registers.PC = address
elif ins == 'CLC':
self._registers.carry = 0
elif ins == 'BCC':
if self._registers.carry == 0:
self._registers.PC = address
elif ins == 'LDA':
self._registers.A = data
self.set_zero_negative(data)
elif ins == 'BEQ':
if self._registers.zero == 1:
self._registers.PC = address
elif ins == 'BNE':
if self._registers.zero == 0:
self._registers.PC = address
elif ins == 'STA':
self.write_address(address, self._registers.A)
elif ins == 'STY':
self.write_address(address, self._registers.Y)
elif ins == 'BIT':
zf = 0 if self._registers.A & data else 1
self._registers.zero = zf
self.set_negative(data)
self.set_overflow(data)
elif ins == 'BVS':
if self._registers.overflow == 1:
self._registers.PC = address
elif ins == 'BVC':
if self._registers.overflow == 0:
self._registers.PC = address
elif ins == 'BPL':
if self._registers.negative == 0:
self._registers.PC = address
elif ins == 'RTS':
pc = self.pop_stack(hex_digit=True)
self._registers.PC = pc + 1
elif ins == 'PHP':
p = FlagByte(self._registers.P)
p[4] = 1 # 当 P 被 指令 PHP BRK 压入栈时， 压入的 P 的第 4 位被设置成 1
self.push_stack(p.value)
elif ins == 'PLA':
data_ = self.pop_stack()
self.set_zero_negative(data_)
self._registers.A = data_
elif ins == 'PLP':
data_ = FlagByte(self.pop_stack())
# 用弹出的值的 第 0 1 2 3 6 7 位 来设置 P 的 第 0 1 2 3 6 7 位 的值
pre_p = self._registers.P
pre_p = FlagByte(pre_p)
data_[4] = pre_p[4]
data_[5] = pre_p[5]
self._registers.P = data_.value
elif ins == 'AND':
a = self._registers.A
a &= data
self.set_zero_negative(a)
self._registers.A = a
elif ins == 'CMP':
result = self._registers.A - data
self.set_zero_negative(result)
self.set_negative(result)
self.set_carry(result >= 0)
elif ins == 'CLD':
self._registers.decimal = 0
elif ins == 'PHA':
self.push_stack(self._registers.A)
elif ins == 'ORA':
self._registers.A |= data
self.set_zero_negative(self._registers.A)
elif ins == 'CLV':
self._registers.overflow = 0
elif ins == 'EOR':
self._registers.A ^= data
self.set_zero_negative(self._registers.A)
elif ins == 'ADC':
a = self._registers.A
result = self._registers.A + data + self._registers.carry
self.set_carry(result >> 8)
low, high = self.split_number(result)
self._registers.A = low
self.set_overflow_by_expression(not ((a ^ data) & 0x80)
and ((a ^ low) & 0x80))
self.set_zero_negative(low)
elif ins == 'LDY':
self._registers.Y = data
self.set_zero_negative(data)
elif ins == 'CPY':
res = self._registers.Y - data
self.set_carry(self._registers.Y >= data)
self.set_zero_negative(res)
elif ins == 'CPX':
res = self._registers.X - data
self.set_carry(self._registers.X >= data)
self.set_zero_negative(res)
elif ins == 'SBC':
res = self._registers.A - data - (0
if self._registers.carry else 1)
low, high = self.split_number(res)
self.set_carry(not high)
self.set_overflow_by_expression(((self._registers.A ^ data) & 0x80)
& ((self._registers.A ^ high)
& 0x80))
self._registers.A = low
self.set_zero_negative(low)
elif ins == 'INY':
res = self._registers.Y + 1
res = self.eight_digit(res)
self.set_zero_negative(res)
self._registers.Y = res
elif ins == 'INX':
res = self._registers.X + 1
res = self.eight_digit(res)
self.set_zero_negative(res)
self._registers.X = res
elif ins == 'DEY':
res = self._registers.Y - 1
res = self.eight_digit(res)
self.set_zero_negative(res)
self._registers.Y = res
elif ins == 'DEX':
res = self._registers.X - 1
res = self.eight_digit(res)
self.set_zero_negative(res)
self._registers.X = res
elif ins == 'TAY':
res = self._registers.A
self.set_zero_negative(res)
self._registers.Y = res
elif ins == 'TAX':
res = self._registers.A
self.set_zero_negative(res)
self._registers.X = res
elif ins == 'TYA':
res = self._registers.Y
self.set_zero_negative(res)
self._registers.A = res
elif ins == 'TXA':
res = self._registers.X
self.set_zero_negative(res)
self._registers.A = res
elif ins == 'TSX':
res = self._registers.S
self.set_zero_negative(res)
self._registers.X = res
elif ins == 'TXS':
res = self._registers.X
self._registers.S = res
elif ins == 'RTI':
p = self.pop_stack()
p = FlagByte(p)
p[4] = self._registers.b_flag
p[5] = 1
self._registers.P = p.value
self._registers.PC = self.pop_stack(hex_digit=True)
elif ins == 'LSR':
if address != -1:
a = data
else:
a = self._registers.A
self._registers.carry = a & 1
a >>= 1
a = self.eight_digit(a)
self.set_zero_negative(a)
if address != -1:
self.write_address(address, a)
else:
self._registers.A = a
elif ins == 'ASL':
if address != -1:
a = data
else:
a = self._registers.A
self._registers.carry = a >> 7
a <<= 1
a = self.eight_digit(a)
self.set_zero_negative(a)
if address != -1:
self.write_address(address, a)
else:
self._registers.A = a
elif ins == 'ROR':
if address != -1:
a = data
else:
a = self._registers.A
zero = a & 1
a >>= 1
a ^= self._registers.carry << 7
self._registers.carry = zero
a = self.eight_digit(a)
self.set_zero_negative(a)
if address != -1:
self.write_address(address, a)
else:
self._registers.A = a
elif ins == 'ROL':
if address != -1:
a = data
else:
a = self._registers.A
seven = (a & 1 << 7) >> 7
a <<= 1
a ^= self._registers.carry
self._registers.carry = seven
a = self.eight_digit(a)
self.set_zero_negative(a)
if address != -1:
self.write_address(address, a)
else:
self._registers.A = a
elif ins == 'NOP':
pass
elif ins == 'BMI':
if self._registers.negative == 1:
self._registers.PC = address
elif ins == "INC":
d = self.eight_digit(data + 1)
self.set_zero_negative(d)
self.write_address(address, d)
elif ins == "DEC":
d = self.eight_digit(data - 1)
self.set_zero_negative(d)
self.write_address(address, d)
elif ins == 'LAX':
self._registers.X = self._registers.A = data
self.set_zero_negative(data)
elif ins == 'SAX':
self.write_address(address, self._registers.A & self._registers.X)
elif ins == 'DCP':
data -= 1
data = self.eight_digit(data)
self.write_address(address, data)
result = self.hex_digit(self._registers.A - data)
self.set_carry(result < 0x100)
self.set_zero_negative(self.eight_digit(result))
elif ins == 'ISB':
data += 1
data = self.eight_digit(data)
self.write_address(address, data)
resul16 = self.hex_digit(self._registers.A - data -
(0 if self._registers.carry else 1))
self.set_carry(not resul16 >> 8)
result8 = self.eight_digit(resul16)
A = self._registers.A
self.set_overflow_by_expression(((A ^ result8) & 0x80)
and ((A ^ data) & 0x80))
self._registers.A = result8
self.set_zero_negative(result8)
elif ins == 'SLO':
self.set_carry(data >> 7)
data <<= 1
data = self.eight_digit(data)
self.write_address(address, data)
self._registers.A |= data
self.set_zero_negative(self._registers.A)
elif ins == 'RLA':
data <<= 1
data = self.hex_digit(data)
if self._registers.carry:
data |= 0x1
self.set_carry(data > 0xff)
result8 = self.eight_digit(data)
self.write_address(address, result8)
a = self._registers.A & result8
self.set_zero_negative(a)
self._registers.A = a
elif ins == 'SRE':
self.set_carry(data & 1)
data >>= 1
data = self.eight_digit(data)
self.write_address(address, data)
a = self._registers.A
a ^= data
self.set_zero_negative(a)
self._registers.A = a
elif ins == 'RRA':
if self._registers.carry:
data |= 0x100
self._registers.carry = data & 1
data >>= 1
self.write_address(address, self.eight_digit(data))
a = self._registers.A
resul16 = a + data + (1 if self._registers.carry else 0)
self.set_carry(resul16 >> 8)
result8 = self.eight_digit(resul16)
self.set_overflow_by_expression(not ((a ^ data) & 0x80)
and ((a ^ result8) & 0x80))
self._registers.A = result8
self.set_zero_negative(result8)
else:
raise NotImplementedError("稍等一下, {} 指令还没实现".format(ins))
class Registers:
PC = 0 # Program Counter
# A = 0 # Accumulator
# X = 0 # Indexes
# Y = 0 # Indexes
# S = 0xFD # Stack Pointer
_INNER = bytearray([0, 0, 0, 0xFD])
_P = FlagByte(0x24) # Status Register
r'''
7 bit 0
---- ----
NVss DIZC
|||| ||||
|||| |||+- Carry
|||| ||+-- Zero
|||| |+--- Interrupt Disable
|||| +---- Decimal
||++------ No CPU effect, see: the B flag
|+-------- Overflow
+--------- Negative
关于 B flag
注意：第几位 是从 第 0 位 开始数的
第 5 位永远为 1
当 P 被 指令 PHP BRK 压入栈时， 压入的 P 的第 4 位被设置成 1
当 P 由于 中断 \IRQ \NMI 被压入栈时， 压入的 P 的第 4 位被设置成 0
当 P 被指令 PLP RTI 设置为栈中弹出的值时，不影响 第 4 5 位
'''
@property
def A(self):
return self._INNER[0]
@A.setter
def A(self, value):
self._INNER[0] = value
@property
def X(self):
return self._INNER[1]
@X.setter
def X(self, value):
self._INNER[1] = value
@property
def Y(self):
return self._INNER[2]
@Y.setter
def Y(self, value):
self._INNER[2] = value
@property
def S(self):
return self._INNER[3]
@S.setter
def S(self, value):
self._INNER[3] = value
@property
def carry(self):
return self._P[0]
@carry.setter
def carry(self, value):
self._P[0] = value
@property
def zero(self):
return self._P[1]
@zero.setter
def zero(self, value):
self._P[1] = value
@property
def interrupt_disable(self):
return self._P[2]
@interrupt_disable.setter
def interrupt_disable(self, value):
self._P[2] = value
@property
def decimal(self):
return self._P[3]
@decimal.setter
def decimal(self, value):
self._P[3] = value
@property
def b_flag(self):
return self._P[4]
@b_flag.setter
def b_flag(self, value):
self._P[4] = value
@property
def overflow(self):
return self._P[6]
@overflow.setter
def overflow(self, value):
self._P[6] = value
@property
def negative(self):
return self._P[7]
@negative.setter
def negative(self, value):
self._P[7] = value
@property
def P(self):
return self._P.value
@P.setter
def P(self, value):
self._P = FlagByte(value)
@classmethod
def to_real_address(cls, sp):
return sp | (0x01 << 8)
def P(self, value):
self._P = FlagByte(value)
def PPUADDR(self):
v = FlagByte(0x0)
v[0:8] = self._PPUADDR[0]
v[8:16] = self._PPUADDR[1]
return v.value
def split_number(cls, num: int):
n = FlagByte(num)
low, high = n[0:8], n[8:16]
return low, high
def from_low_high_to_int(cls, low: int or bytes, high: int or bytes):
v = FlagByte(0x0)
v[0:8] = low
v[8:16] = high
return v.value
def low_high(cls, val):
pc = FlagByte(val)
return pc[0:8], pc[8:16]