def jp_a16():
cpu.add_ticks(16)
lower = memory.read(cpu.registers.PC)
upper = memory.read(cpu.registers.PC+1)
jaddress = (upper << 8) | (lower & 0xFF)
cpu.registers.PC = jaddress
return
def helper():
cpu.add_ticks(8)
# memory access costs 4 ticks more
if opcode == 0x36:
cpu.add_ticks(4)
# get the register, and read in the opcode 'argument'
reg = _d8regmap[opcode]
cpu.registers[reg] = memory.read(cpu.registers.PC +1)
cpu.registers.PC += 1
def helper():
destreg = 0
opcode -= 0x40
while(opcode >= 0x08):
opcode -= 0x08
destreg += 1
cpu.add_ticks(4)
# These access memory, and take longer
if (opcode == 0x06 or destreg == 0x06):
cpu.add_ticks(4)
dest = REGISTER_MAP[destreg]
cpu.registers[dest] = cpu.registers[REGISTER_MAP[opcode]]
def func(opcode):
bit = 0
opcode -= base_opcode
while (opcode >= 0x08):
opcode -= 0x08
bit = bit + 1
if opcode == 0x06:
cpu.add_ticks(16)
else:
cpu.add_ticks(8)
register = REGISTER_MAP[opcode]
cpu.registers[register] = op(cpu.registers[register], bit)
def nop():
cpu.add_ticks(4)
return
def ldh_a_n():
cpu.add_ticks(12)
n = memory.read(cpu.registers.PC)
cpu.registers.PC += 1
cpu.registers.A = memory.read(0xFF00+n)
def ldh_n_a():
cpu.add_ticks(12)
n = memory.read(cpu.registers.PC)
cpu.registers.PC += 1
memory.write(0xFF00+n, cpu.registers.A)
def ld_a_ic(): # ld A,(C)
cpu.add_ticks(8)
cpu.registers.A = memory.read(0xFF00 + cpu.registers.C)
def ld_ic_a(): # LD (C), A
cpu.add_ticks(8)
memory.write(0xFF00 + cpu.registers.C, cpu.registers.A)