def next(self):
if not self._machine_code:
raise StopIteration
else:
self._current_oprt = self._machine_code.next()
if self._current_oprt in self.OPRT_R_R:
regs = self._machine_code.next()
return InstRR(self._current_oprt,
hn(regs), ln(regs))
elif self._current_oprt in self.OPRT_R_IMM:
reg = self._machine_code.next()
imm = mkw(self._machine_code.next(),
self._machine_code.next())
return InstRImm(self._current_oprt,
hn(reg), i_2c(imm))
elif self._current_oprt in self.OPRT_R:
reg = self._machine_code.next()
return InstR(self._current_oprt,
hn(reg))
elif self._current_oprt in self.OPRT_IMM_1_BYTE:
imm = self._machine_code.next()
return InstImm(self._current_oprt,
i_2c(imm, size=8))
elif self._current_oprt in self.OPRT_IMM_2_BYTE:
# operators with one 2-byte imm arg are always 2-byte long
self._current_oprt = mkw(self._current_oprt,
self._machine_code.next())
imm = mkw(self._machine_code.next(),
self._machine_code.next())
return InstImm(self._current_oprt,
i_2c(imm))
elif self._current_oprt in self.OPRT_NO_ARG:
return InstNoArg(self._current_oprt)
def _ins_decode(self):
self._d_dr, self._d_sr = (self._reg_mux(self._ir[1] >> 4),
self._reg_mux(self._ir[1] & 0x0f))
# both of _d_xr are str
op_code = self._ir[0] & 0x1f
if self._ir[0] & 0xe0 == 0:
# arithmetic instruction
self.__f_single = False
self.__f_modify = False
self.__f_z = False
self.__f_c = False
if op_code in self._op_code_z_c_binary_table:
self.__f_modify = True
self.__f_z = True
self.__f_c = True
elif op_code in self._op_code_z_c_binary_n_table:
self.__f_z = True
self.__f_c = True
elif op_code in self._op_code_z_binary_table:
self.__f_modify = True
self.__f_z = True
elif op_code in self._op_code_z_binary_n_table:
self.__f_z = True
elif op_code in self._op_code_z_c_unary_table:
self.__f_single = True
self.__f_modify = True
self.__f_z = True
self.__f_c = True
elif op_code in self._op_code_z_unary_table:
self.__f_single = True
self.__f_modify = True
self.__f_z = True
elif op_code in self._op_code_binary_table:
self.__f_modify = True
self._alu_func = self._op_codes[op_code]
result, carry, zero = self._alu_proc()
if self.__f_modify:
self.__setattr__(self._d_dr, result)
if self.__f_c:
self._c_flag = carry
if self.__f_z:
self._z_flag = zero
elif self._ir[0] & 0xe0 == 0x40:
# jump instruction
absolute, jump = False, False
if op_code == 0: # jr
jump = True
elif op_code == 0x04: # jrc
jump = self._c_flag
elif op_code == 0x05:
jump = not self._c_flag # jrnc
elif op_code == 0x02:
jump = self._z_flag # jrz
elif op_code == 0x03:
jump = not self._z_flag # jrnz
elif op_code == 0x0f: # jmpa
jump = True
absolute = True
if not absolute:
if jump:
self._pc += i_2c(self._ir[1], size=8)
if absolute:
self._pc = i_2c(mkw(*self._next_word()))
elif self._ir[0] & 0xe0 == 0x80:
# memory instruction
if op_code == 0x01:
self.__setattr__(self._d_dr,
i_2c(mkw(*self._next_word()),
size=16))
