mirror of
https://github.com/MoleskiCoder/EightBit.git
synced 2024-09-01 15:29:11 +00:00
408 lines
8.9 KiB
C++
408 lines
8.9 KiB
C++
#pragma once
|
|
|
|
#include <cstdint>
|
|
#include <cassert>
|
|
|
|
#include "IntelProcessor.h"
|
|
#include "InputOutput.h"
|
|
#include "Signal.h"
|
|
|
|
namespace EightBit {
|
|
class Z80 : public IntelProcessor {
|
|
public:
|
|
struct refresh_t {
|
|
|
|
bool high : 1;
|
|
uint8_t variable : 7;
|
|
|
|
refresh_t(uint8_t value)
|
|
: high((value & Bit7) != 0),
|
|
variable(value & Mask7)
|
|
{ }
|
|
|
|
operator uint8_t() const {
|
|
return (high << 7) | variable;
|
|
}
|
|
|
|
refresh_t& operator++() {
|
|
++variable;
|
|
return *this;
|
|
}
|
|
};
|
|
|
|
enum StatusBits {
|
|
SF = Bit7,
|
|
ZF = Bit6,
|
|
YF = Bit5,
|
|
HC = Bit4,
|
|
XF = Bit3,
|
|
PF = Bit2,
|
|
VF = Bit2,
|
|
NF = Bit1,
|
|
CF = Bit0,
|
|
};
|
|
|
|
Z80(Bus& bus, InputOutput& ports);
|
|
|
|
Signal<Z80> ExecutingInstruction;
|
|
|
|
int interruptMaskable(uint8_t value) { return interrupt(true, value); }
|
|
int interruptMaskable() { return interruptMaskable(0); }
|
|
int interruptNonMaskable() { return interrupt(false, 0); }
|
|
|
|
int interrupt(bool maskable, uint8_t value);
|
|
|
|
virtual int execute(uint8_t opcode);
|
|
int step();
|
|
|
|
virtual register16_t& AF() override {
|
|
return m_accumulatorFlags[m_accumulatorFlagsSet];
|
|
}
|
|
|
|
virtual register16_t& BC() override {
|
|
return m_registers[m_registerSet][BC_IDX];
|
|
}
|
|
|
|
virtual register16_t& DE() override {
|
|
return m_registers[m_registerSet][DE_IDX];
|
|
}
|
|
|
|
virtual register16_t& HL() override {
|
|
return m_registers[m_registerSet][HL_IDX];
|
|
}
|
|
|
|
register16_t& IX() { return m_ix; }
|
|
uint8_t& IXH() { return IX().high; }
|
|
uint8_t& IXL() { return IX().low; }
|
|
|
|
register16_t& IY() { return m_iy; }
|
|
uint8_t& IYH() { return IY().high; }
|
|
uint8_t& IYL() { return IY().low; }
|
|
|
|
refresh_t& REFRESH() { return m_refresh; }
|
|
uint8_t& IV() { return iv; }
|
|
int& IM() { return m_interruptMode; }
|
|
bool& IFF1() { return m_iff1; }
|
|
bool& IFF2() { return m_iff2; }
|
|
|
|
bool& M1() { return m1; }
|
|
|
|
void exx() {
|
|
m_registerSet ^= 1;
|
|
}
|
|
|
|
void exxAF() {
|
|
m_accumulatorFlagsSet = !m_accumulatorFlagsSet;
|
|
}
|
|
|
|
virtual void reset() override;
|
|
|
|
protected:
|
|
virtual int fetchExecute() override {
|
|
M1() = true;
|
|
return IntelProcessor::fetchExecute();
|
|
}
|
|
|
|
private:
|
|
InputOutput& m_ports;
|
|
|
|
enum { BC_IDX, DE_IDX, HL_IDX };
|
|
|
|
std::array<std::array<register16_t, 3>, 2> m_registers;
|
|
int m_registerSet;
|
|
|
|
std::array<register16_t, 2> m_accumulatorFlags;
|
|
int m_accumulatorFlagsSet;
|
|
|
|
register16_t m_ix;
|
|
register16_t m_iy;
|
|
|
|
refresh_t m_refresh;
|
|
|
|
uint8_t iv;
|
|
int m_interruptMode;
|
|
bool m_iff1;
|
|
bool m_iff2;
|
|
|
|
bool m1;
|
|
|
|
bool m_prefixCB;
|
|
bool m_prefixDD;
|
|
bool m_prefixED;
|
|
bool m_prefixFD;
|
|
|
|
int8_t m_displacement;
|
|
bool m_displaced;
|
|
|
|
uint16_t displacedAddress() {
|
|
assert(m_displaced);
|
|
return MEMPTR().word = (m_prefixDD ? IX() : IY()).word + m_displacement;
|
|
}
|
|
|
|
void fetchDisplacement() {
|
|
m_displacement = fetchByte();
|
|
}
|
|
|
|
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 HL2().high;
|
|
case 5:
|
|
return HL2().low;
|
|
case 6:
|
|
return getByte(m_displaced ? displacedAddress() : HL().word);
|
|
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:
|
|
HL2().high = value;
|
|
break;
|
|
case 5:
|
|
HL2().low = value;
|
|
break;
|
|
case 6:
|
|
setByte(m_displaced ? displacedAddress() : HL().word, value);
|
|
break;
|
|
case 7:
|
|
a = value;
|
|
break;
|
|
default:
|
|
UNREACHABLE;
|
|
}
|
|
}
|
|
|
|
uint8_t R2(int r, const 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 R2(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) {
|
|
switch (rp) {
|
|
case 3:
|
|
return SP();
|
|
case HL_IDX:
|
|
return HL2();
|
|
default:
|
|
return m_registers[m_registerSet][rp];
|
|
}
|
|
}
|
|
|
|
register16_t& HL2() {
|
|
if (!m_displaced)
|
|
return HL();
|
|
if (m_prefixDD)
|
|
return IX();
|
|
// Must be FD prefix
|
|
return IY();
|
|
}
|
|
|
|
register16_t& RP2(int rp) {
|
|
switch (rp) {
|
|
case 3:
|
|
return AF();
|
|
case HL_IDX:
|
|
return HL2();
|
|
default:
|
|
return m_registers[m_registerSet][rp];
|
|
}
|
|
}
|
|
|
|
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 adjustOverflowAdd(uint8_t& f, uint8_t before, uint8_t value, uint8_t calculation) {
|
|
adjustOverflowAdd(f, before & SF, value & SF, calculation & SF);
|
|
}
|
|
|
|
static void adjustOverflowAdd(uint8_t& f, int beforeNegative, int valueNegative, int afterNegative) {
|
|
auto overflow = (beforeNegative == valueNegative) && (beforeNegative != afterNegative);
|
|
setFlag(f, VF, overflow);
|
|
}
|
|
|
|
static void adjustOverflowSub(uint8_t& f, uint8_t before, uint8_t value, uint8_t calculation) {
|
|
adjustOverflowSub(f, before & SF, value & SF, calculation & SF);
|
|
}
|
|
|
|
static void adjustOverflowSub(uint8_t& f, int beforeNegative, int valueNegative, int afterNegative) {
|
|
auto overflow = (beforeNegative != valueNegative) && (beforeNegative != afterNegative);
|
|
setFlag(f, VF, overflow);
|
|
}
|
|
|
|
static void subtract(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0);
|
|
|
|
void executeCB(int x, int y, int z);
|
|
void executeED(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 di();
|
|
void ei();
|
|
|
|
void retn();
|
|
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 sbc(uint8_t& f, register16_t& operand, register16_t value);
|
|
void adc(uint8_t& f, register16_t& operand, register16_t value);
|
|
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 sub(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0);
|
|
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 sll(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);
|
|
|
|
void xhtl(register16_t& operand);
|
|
|
|
void blockCompare(uint8_t a, uint8_t& f);
|
|
|
|
void cpi(uint8_t a, uint8_t& f);
|
|
bool cpir(uint8_t a, uint8_t& f);
|
|
|
|
void cpd(uint8_t a, uint8_t& f);
|
|
bool cpdr(uint8_t a, uint8_t& f);
|
|
|
|
void blockLoad(uint8_t a, uint8_t& f, register16_t source, register16_t destination);
|
|
|
|
void ldi(uint8_t a, uint8_t& f);
|
|
bool ldir(uint8_t a, uint8_t& f);
|
|
|
|
void ldd(uint8_t a, uint8_t& f);
|
|
bool lddr(uint8_t a, uint8_t& f);
|
|
|
|
void ini(uint8_t& f);
|
|
bool inir(uint8_t& f);
|
|
|
|
void ind(uint8_t& f);
|
|
bool indr(uint8_t& f);
|
|
|
|
void blockOut(uint8_t& f);
|
|
|
|
void outi(uint8_t& f);
|
|
bool otir(uint8_t& f);
|
|
|
|
void outd(uint8_t& f);
|
|
bool otdr(uint8_t& f);
|
|
|
|
static void neg(uint8_t& a, uint8_t& f);
|
|
|
|
void rrd(uint8_t& a, uint8_t& f);
|
|
void rld(uint8_t& a, uint8_t& f);
|
|
|
|
void writePort(uint8_t port, uint8_t a);
|
|
void writePort();
|
|
|
|
void readPort(uint8_t port, uint8_t& a);
|
|
void readPort();
|
|
};
|
|
} |