EightBit/LR35902/inc/LR35902.h
Adrian Conlon 9f404d46a4 The LR35902 instruction set doesn't really need the "bit" instruction to return a value.
Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
2019-07-21 11:25:56 +01:00

213 lines
4.1 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;
auto clockCycles() const {
return cycles() * 4;
}
virtual register16_t& AF() final;
virtual register16_t& BC() final;
virtual register16_t& DE() final;
virtual register16_t& HL() final;
protected:
virtual int execute() final;
virtual int step() final;
virtual void handleRESET() final;
virtual void handleINT() final;
private:
Bus& m_bus;
register16_t af = 0xffff;
register16_t bc = 0xffff;
register16_t de = 0xffff;
register16_t hl = 0xffff;
bool m_ime = false;
bool m_stopped = false;
bool m_prefixCB = false;
bool& IME() { return m_ime; }
auto R(const int r) {
ASSUME(r >= 0);
ASSUME(r <= 7);
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 busRead(HL());
case 7:
return A();
default:
UNREACHABLE;
}
}
void R(const int r, const uint8_t value) {
ASSUME(r >= 0);
ASSUME(r <= 7);
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:
busWrite(HL(), value);
break;
case 7:
A() = value;
break;
default:
UNREACHABLE;
}
}
auto& RP(const int rp) {
ASSUME(rp >= 0);
ASSUME(rp <= 3);
switch (rp) {
case 0b00:
return BC();
case 0b01:
return DE();
case 0b10:
return HL();
case 0b11:
return SP();
default:
UNREACHABLE;
}
}
auto& RP2(const int rp) {
ASSUME(rp >= 0);
ASSUME(rp <= 3);
switch (rp) {
case 0b00:
return BC();
case 0b01:
return DE();
case 0b10:
return HL();
case 0b11:
return AF();
default:
UNREACHABLE;
}
}
void adjustHalfCarryAdd(const uint8_t before, const uint8_t value, const int calculation) {
setFlag(F(), HC, calculateHalfCarryAdd(before, value, calculation));
}
void adjustHalfCarrySub(const uint8_t before, const uint8_t value, const int calculation) {
setFlag(F(), HC, calculateHalfCarrySub(before, value, calculation));
}
void subtract(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);
void increment(uint8_t& operand);
void decrement(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(int flag);
bool returnConditionalFlag(int flag);
bool jumpConditionalFlag(int flag);
bool callConditionalFlag(int flag);
void add(register16_t& operand, register16_t value);
void add(uint8_t& operand, uint8_t value, int carry = 0);
void adc(uint8_t& operand, uint8_t value);
void sbc(uint8_t value);
void andr(uint8_t& operand, uint8_t value);
void xorr(uint8_t value);
void orr(uint8_t value);
void compare(uint8_t check, uint8_t value);
uint8_t rlc(uint8_t operand);
uint8_t rrc(uint8_t operand);
uint8_t rl(uint8_t operand);
uint8_t rr(uint8_t operand);
uint8_t sla(uint8_t operand);
uint8_t sra(uint8_t operand);
uint8_t srl(uint8_t operand);
void bit(int n, uint8_t operand);
static uint8_t res(int n, uint8_t operand);
static uint8_t set(int n, uint8_t operand);
void daa();
void scf();
void ccf();
void cpl();
uint8_t swap(uint8_t operand);
};
}
}