EightBit/LR35902/inc/LR35902.h
Adrian Conlon a1c753d63e Couple of small tidy ups on the LR35902 implementation.
Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
2017-12-10 21:57:32 +00:00

214 lines
4.8 KiB
C++

#pragma once
#include <cstdint>
#include <cassert>
#include <IntelProcessor.h>
#include <Signal.h>
#include <Register.h>
namespace EightBit {
namespace GameBoy {
class Bus;
class LR35902 final : public IntelProcessor {
public:
enum StatusBits {
ZF = Bit7,
NF = Bit6,
HC = Bit5,
CF = Bit4,
};
LR35902(Bus& memory);
Signal<LR35902> ExecutingInstruction;
Signal<LR35902> ExecutedInstruction;
int clockCycles() const {
return cycles() * 4;
}
virtual register16_t& AF() final {
af.low &= 0xf0;
return af;
}
virtual register16_t& BC() final { return bc; }
virtual register16_t& DE() final { return de; }
virtual register16_t& HL() final { return hl; }
int singleStep();
protected:
virtual void reset() final;
virtual int execute(uint8_t opcode) final;
virtual int step() final;
private:
Bus& m_bus;
register16_t af = { { 0xff, 0xff } };
register16_t bc = { { 0xff, 0xff } };
register16_t de = { { 0xff, 0xff } };
register16_t hl = { { 0xff, 0xff } };
bool m_ime = false;
bool m_stopped = false;
bool m_prefixCB = false;
bool& IME() { return m_ime; }
uint8_t R(int r, uint8_t& a) {
switch (r) {
case 0:
return B();
case 1:
return C();
case 2:
return D();
case 3:
return E();
case 4:
return H();
case 5:
return L();
case 6:
return getByte(HL());
case 7:
return a;
default:
UNREACHABLE;
}
throw std::logic_error("Unhandled registry mechanism");
}
void R(int r, uint8_t& a, uint8_t value) {
switch (r) {
case 0:
B() = value;
break;
case 1:
C() = value;
break;
case 2:
D() = value;
break;
case 3:
E() = value;
break;
case 4:
H() = value;
break;
case 5:
L() = value;
break;
case 6:
setByte(HL(), value);
break;
case 7:
a = value;
break;
default:
UNREACHABLE;
}
}
register16_t& RP(int rp) {
assert(rp < 4);
assert(rp >= 0);
switch (rp) {
case 0b00:
return BC();
case 0b01:
return DE();
case 0b10:
return HL();
case 0b11:
return SP();
default:
UNREACHABLE;
}
}
register16_t& RP2(int rp) {
assert(rp < 4);
assert(rp >= 0);
switch (rp) {
case 0b00:
return BC();
case 0b01:
return DE();
case 0b10:
return HL();
case 0b11:
return AF();
default:
UNREACHABLE;
}
}
static void adjustHalfCarryAdd(uint8_t& f, uint8_t before, uint8_t value, int calculation) {
setFlag(f, HC, calculateHalfCarryAdd(before, value, calculation));
}
static void adjustHalfCarrySub(uint8_t& f, uint8_t before, uint8_t value, int calculation) {
setFlag(f, HC, calculateHalfCarrySub(before, value, calculation));
}
static void subtract(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0);
void executeCB(int x, int y, int z, int p, int q);
void executeOther(int x, int y, int z, int p, int q);
static void increment(uint8_t& f, uint8_t& operand);
static void decrement(uint8_t& f, uint8_t& operand);
void stop() { m_stopped = true; }
void start() { m_stopped = false; }
bool stopped() const { return m_stopped; }
void di();
void ei();
void reti();
bool jrConditionalFlag(uint8_t& f, int flag);
bool returnConditionalFlag(uint8_t& f, int flag);
bool jumpConditionalFlag(uint8_t& f, int flag);
bool callConditionalFlag(uint8_t& f, int flag);
void add(uint8_t& f, register16_t& operand, register16_t value);
static void add(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0);
static void adc(uint8_t& f, uint8_t& operand, uint8_t value);
static void sbc(uint8_t& f, uint8_t& operand, uint8_t value);
static void andr(uint8_t& f, uint8_t& operand, uint8_t value);
static void xorr(uint8_t& f, uint8_t& operand, uint8_t value);
static void orr(uint8_t& f, uint8_t& operand, uint8_t value);
static void compare(uint8_t& f, uint8_t check, uint8_t value);
static uint8_t rlc(uint8_t& f, uint8_t operand);
static uint8_t rrc(uint8_t& f, uint8_t operand);
static uint8_t rl(uint8_t& f, uint8_t operand);
static uint8_t rr(uint8_t& f, uint8_t operand);
static uint8_t sla(uint8_t& f, uint8_t operand);
static uint8_t sra(uint8_t& f, uint8_t operand);
static uint8_t srl(uint8_t& f, uint8_t operand);
static uint8_t bit(uint8_t& f, int n, uint8_t operand);
static uint8_t res(int n, uint8_t operand);
static uint8_t set(int n, uint8_t operand);
static void daa(uint8_t& a, uint8_t& f);
static void scf(uint8_t& a, uint8_t& f);
static void ccf(uint8_t& a, uint8_t& f);
static void cpl(uint8_t& a, uint8_t& f);
static uint8_t swap(uint8_t& f, uint8_t operand);
};
}
}