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ComSquare/sources/CPU/CPU.cpp
AnonymusRaccoon 8addb29610 Implementing instructions cycles
2020-02-11 17:39:06 +01:00

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//
// Created by anonymus-raccoon on 1/24/20.
//
#include "CPU.hpp"
#include <utility>
#include <iostream>
#include "../Exceptions/NotImplementedException.hpp"
#include "../Exceptions/InvalidAddress.hpp"
#include "../Exceptions/InvalidOpcode.hpp"
namespace ComSquare::CPU
{
CPU::CPU(std::shared_ptr<Memory::MemoryBus> bus, Cartridge::Header &cartridgeHeader)
: _bus(std::move(bus)), _cartridgeHeader(cartridgeHeader)
{
this->_registers.pc = this->_cartridgeHeader.emulationInterrupts.reset;
}
//! @bref The CPU's internal registers starts at $4200 and finish at $421F.
uint8_t CPU::read(uint24_t addr)
{
switch (addr) {
case 0x0:
return this->_internalRegisters.nmitimen;
case 0x1:
return this->_internalRegisters.wrio;
case 0x2:
return this->_internalRegisters.wrmpya;
case 0x3:
return this->_internalRegisters.wrmpyb;
case 0x4:
return this->_internalRegisters.wrdivl;
case 0x5:
return this->_internalRegisters.wrdivh;
case 0x6:
return this->_internalRegisters.wrdivb;
case 0x7:
return this->_internalRegisters.htimel;
case 0x8:
return this->_internalRegisters.htimeh;
case 0x9:
return this->_internalRegisters.vtimel;
case 0xA:
return this->_internalRegisters.vtimeh;
case 0xB:
return this->_internalRegisters.mdmaen;
case 0xC:
return this->_internalRegisters.hdmaen;
case 0xD:
return this->_internalRegisters.memsel;
case 0x10:
return this->_internalRegisters.rdnmi;
case 0x11:
return this->_internalRegisters.timeup;
case 0x12:
return this->_internalRegisters.hvbjoy;
case 0x13:
return this->_internalRegisters.rdio;
case 0x14:
return this->_internalRegisters.rddivl;
case 0x15:
return this->_internalRegisters.rddivh;
case 0x16:
return this->_internalRegisters.rdmpyl;
case 0x17:
return this->_internalRegisters.rdmpyh;
case 0x18:
return this->_internalRegisters.joy1l;
case 0x19:
return this->_internalRegisters.joy1h;
case 0x1A:
return this->_internalRegisters.joy2l;
case 0x1B:
return this->_internalRegisters.joy2h;
case 0x1C:
return this->_internalRegisters.joy3l;
case 0x1D:
return this->_internalRegisters.joy3h;
case 0x1E:
return this->_internalRegisters.joy4l;
case 0x1F:
return this->_internalRegisters.joy4h;
default:
throw InvalidAddress("CPU Internal Registers read", addr);
}
}
void CPU::write(uint24_t addr, uint8_t data)
{
switch (addr) {
case 0x0:
this->_internalRegisters.nmitimen = data;
break;
case 0x1:
this->_internalRegisters.wrio = data;
break;
case 0x2:
this->_internalRegisters.wrmpya = data;
break;
case 0x3:
this->_internalRegisters.wrmpyb = data;
break;
case 0x4:
this->_internalRegisters.wrdivl = data;
break;
case 0x5:
this->_internalRegisters.wrdivh = data;
break;
case 0x6:
this->_internalRegisters.wrdivb = data;
break;
case 0x7:
this->_internalRegisters.htimel = data;
break;
case 0x8:
this->_internalRegisters.htimeh = data;
break;
case 0x9:
this->_internalRegisters.vtimel = data;
break;
case 0xA:
this->_internalRegisters.vtimeh = data;
break;
case 0xB:
this->_internalRegisters.mdmaen = data;
break;
case 0xC:
this->_internalRegisters.hdmaen = data;
break;
case 0xD:
this->_internalRegisters.memsel = data;
break;
case 0x10:
this->_internalRegisters.rdnmi = data;
break;
case 0x11:
this->_internalRegisters.timeup = data;
break;
case 0x12:
this->_internalRegisters.hvbjoy = data;
break;
case 0x13:
this->_internalRegisters.rdio = data;
break;
case 0x14:
this->_internalRegisters.rddivl = data;
break;
case 0x15:
this->_internalRegisters.rddivh = data;
break;
case 0x16:
this->_internalRegisters.rdmpyl = data;
break;
case 0x17:
this->_internalRegisters.rdmpyh = data;
break;
case 0x18:
this->_internalRegisters.joy1l = data;
break;
case 0x19:
this->_internalRegisters.joy1h = data;
break;
case 0x1A:
this->_internalRegisters.joy2l = data;
break;
case 0x1B:
this->_internalRegisters.joy2h = data;
break;
case 0x1C:
this->_internalRegisters.joy3l = data;
break;
case 0x1D:
this->_internalRegisters.joy3h = data;
break;
case 0x1E:
this->_internalRegisters.joy4l = data;
break;
case 0x1F:
this->_internalRegisters.joy4h = data;
break;
default:
throw InvalidAddress("CPU Internal Registers write", addr);
}
}
unsigned CPU::update()
{
unsigned cycles = 0;
for (int i = 0; i < 0xFF; i++)
cycles += this->executeInstruction();
return cycles;
}
unsigned CPU::executeInstruction()
{
uint8_t opcode = this->_bus->read(this->_registers.pc);
this->_extraMemoryCycles = 0;
switch (opcode) {
case Instructions::BRK: return 7 + this->BRK();
case Instructions::ADC_IM: return 2 + this->ADC(this->_getImmediateAddr());
case Instructions::ADC_ABS: return 4 + this->ADC(this->_getAbsoluteAddr());
case Instructions::ADC_ABSl: return 5 + this->ADC(this->_getAbsoluteLongAddr());
case Instructions::ADC_DP: return 3 + this->ADC(this->_getDirectAddr());
case Instructions::ADC_DPi: return 5 + this->ADC(this->_getDirectIndirectAddr());
case Instructions::ADC_DPil: return 6 + this->ADC(this->_getDirectIndirectLongAddr());
case Instructions::ADC_ABSX: return 4 + this->ADC(this->_getAbsoluteIndexedByXAddr());
case Instructions::ADC_ABSXl:return 5 + this->ADC(this->_getAbsoluteIndexedByXLongAddr());
case Instructions::ADC_ABSY: return 4 + this->ADC(this->_getAbsoluteIndexedByYAddr());
case Instructions::ADC_DPX: return 4 + this->ADC(this->_getDirectIndexedByXAddr());
case Instructions::ADC_DPXi: return 6 + this->ADC(this->_getDirectIndirectIndexedXAddr());
case Instructions::ADC_DPYi: return 5 + this->ADC(this->_getDirectIndirectIndexedYAddr());
case Instructions::ADC_DPYil:return 6 + this->ADC(this->_getDirectIndirectIndexedYLongAddr());
case Instructions::ADC_SR: return 4 + this->ADC(this->_getStackRelativeAddr());
case Instructions::ADC_SRYi: return 7 + this->ADC(this->_getStackRelativeIndirectIndexedYAddr());
default:
return 0;
//throw InvalidOpcode("CPU", opcode);
}
}
////////////////////////////////////////////////////////////////////
/// Addressing modes
////////////////////////////////////////////////////////////////////
uint24_t CPU::_getImmediateAddr()
{
uint24_t effective = this->_registers.pac++;
if (this->_registers.p.m)
this->_registers.pac++;
return effective;
}
uint24_t CPU::_getDirectAddr()
{
if (this->_registers.dl != 0)
this->_extraMemoryCycles++;
uint8_t addr = this->_bus->read(this->_registers.pac++);
return this->_registers.d + addr;
}
uint24_t CPU::_getAbsoluteAddr()
{
uint24_t addr = this->_registers.dbr << 16u;
addr += this->_bus->read(this->_registers.pac++);
addr += this->_bus->read(this->_registers.pac++) << 8u;
return addr;
}
uint24_t CPU::_getAbsoluteLongAddr()
{
uint24_t addr = this->_bus->read(this->_registers.pac++);
addr += this->_bus->read(this->_registers.pac++) << 8u;
addr += this->_bus->read(this->_registers.pac++) << 16u;
return addr;
}
uint24_t CPU::_getDirectIndirectIndexedYAddr()
{
if (this->_registers.dl != 0)
this->_extraMemoryCycles++;
uint16_t dp = this->_bus->read(this->_registers.pac++) + this->_registers.d;
uint24_t base = this->_bus->read(dp);
base += this->_bus->read(dp + 1) << 8u;
base += this->_registers.dbr << 16u;
if ((base & 0xF0000000u) == (((base + this->_registers.y) & 0xF0000000u)))
this->_extraMemoryCycles++;
return base + this->_registers.y;
}
uint24_t CPU::_getDirectIndirectIndexedYLongAddr()
{
if (this->_registers.dl != 0)
this->_extraMemoryCycles++;
uint16_t dp = this->_bus->read(this->_registers.pac++) + this->_registers.d;
uint24_t base = this->_bus->read(dp);
base += this->_bus->read(dp + 1) << 8u;
base += this->_bus->read(dp + 2) << 16u;
return base;
}
uint24_t CPU::_getDirectIndirectIndexedXAddr()
{
if (this->_registers.dl != 0)
this->_extraMemoryCycles++;
uint16_t dp = this->_bus->read(this->_registers.pac++) + this->_registers.d;
dp += this->_registers.x;
uint24_t base = this->_bus->read(dp);
base += this->_bus->read(dp + 1) << 8u;
base += this->_registers.dbr << 16u;
return base;
}
uint24_t CPU::_getDirectIndexedByXAddr()
{
if (this->_registers.dl != 0)
this->_extraMemoryCycles++;
uint16_t dp = this->_bus->read(this->_registers.pac++) + this->_registers.d;
dp += this->_registers.x;
return dp;
}
uint24_t CPU::_getDirectIndexedByYAddr()
{
if (this->_registers.dl != 0)
this->_extraMemoryCycles++;
uint16_t dp = this->_bus->read(this->_registers.pac++) + this->_registers.d;
dp += this->_registers.y;
return dp;
}
uint24_t CPU::_getAbsoluteIndexedByXAddr()
{
uint16_t abs = this->_bus->read(this->_registers.pac++);
abs += this->_bus->read(this->_registers.pac++) << 8u;
uint24_t effective = abs + (this->_registers.dbr << 16u);
if ((effective & 0xF0000000u) == (((effective + this->_registers.x) & 0xF0000000u)))
this->_extraMemoryCycles++;
return effective + this->_registers.x;
}
uint24_t CPU::_getAbsoluteIndexedByYAddr()
{
uint16_t abs = this->_bus->read(this->_registers.pac++);
abs += this->_bus->read(this->_registers.pac++) << 8u;
uint24_t effective = abs + (this->_registers.dbr << 16u);
if ((effective & 0xF0000000u) == (((effective + this->_registers.y) & 0xF0000000u)))
this->_extraMemoryCycles++;
return effective + this->_registers.y;
}
uint24_t CPU::_getAbsoluteIndexedByXLongAddr()
{
uint24_t lng = this->_bus->read(this->_registers.pac++);
lng += this->_bus->read(this->_registers.pac++) << 8u;
lng += this->_bus->read(this->_registers.pac++) << 16u;
return lng + this->_registers.x;
}
uint24_t CPU::_getProgramCounterRelativeAddr()
{
uint24_t pc = this->_registers.pac;
int8_t mod = this->_bus->read(this->_registers.pac++);
return pc + mod;
}
uint24_t CPU::_getProgramCounterRelativeLongAddr()
{
uint24_t pc = this->_registers.pac;
uint8_t val1 = this->_bus->read(this->_registers.pac++);
uint8_t val2 = this->_bus->read(this->_registers.pac++);
int16_t mod = val2 > 0x7F ? (static_cast<char>(val2) * 256 - val1) : (val1 | val2 << 8u);
return pc + mod;
}
uint24_t CPU::_getAbsoluteIndirectAddr()
{
uint16_t abs = this->_bus->read(this->_registers.pac++);
abs += this->_bus->read(this->_registers.pac++) << 8u;
uint24_t effective = this->_bus->read(abs);
effective += this->_bus->read(abs + 1) << 8u;
return effective;
}
uint24_t CPU::_getAbsoluteIndexedIndirectAddr()
{
uint24_t abs = this->_bus->read(this->_registers.pac++);
abs += this->_bus->read(this->_registers.pac++) << 8u;
abs += this->_registers.x;
uint24_t effective = this->_bus->read(abs);
effective += this->_bus->read(abs + 1) << 8u;
return effective;
}
uint24_t CPU::_getDirectIndirectAddr()
{
if (this->_registers.dl != 0)
this->_extraMemoryCycles++;
uint16_t dp = this->_bus->read(this->_registers.pac++) + this->_registers.d;
uint24_t effective = this->_bus->read(dp);
effective += this->_bus->read(dp + 1) << 8u;
effective += this->_registers.dbr << 16u;
return effective;
}
uint24_t CPU::_getDirectIndirectLongAddr()
{
if (this->_registers.dl != 0)
this->_extraMemoryCycles++;
uint16_t dp = this->_bus->read(this->_registers.pac++) + this->_registers.d;
uint24_t effective = this->_bus->read(dp);
effective += this->_bus->read(++dp) << 8u;
effective += this->_bus->read(++dp) << 16u;
return effective;
}
uint24_t CPU::_getStackRelativeAddr()
{
return this->_bus->read(this->_registers.pac++) + this->_registers.s;
}
uint24_t CPU::_getStackRelativeIndirectIndexedYAddr()
{
uint24_t base = this->_bus->read(this->_registers.pac++) + this->_registers.s;
base += this->_registers.dbr << 16u;
return base + this->_registers.y;
}
}
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