Files
ComSquare/sources/CPU/Instructions/MathematicalOperations.cpp
AnonymusRaccoon b2a60efb4e Finishing the ADC
2020-02-11 15:53:37 +01:00

28 lines
897 B
C++

//
// Created by anonymus-raccoon on 2/10/20.
//
#include <iostream>
#include "../CPU.hpp"
namespace ComSquare::CPU
{
int CPU::ADC(uint24_t valueAddr)
{
unsigned value = this->_bus->read(valueAddr) + this->_registers.p.c;
unsigned negativeMask = this->_isEmulationMode ? 0xF0u : 0xF000u;
unsigned maxValue = this->_isEmulationMode ? UINT8_MAX : UINT16_MAX;
this->_registers.p.c = static_cast<unsigned>(this->_registers.a) + value > maxValue;
if ((this->_registers.a & negativeMask) == (value & negativeMask))
this->_registers.p.v = (this->_registers.a & negativeMask) != ((this->_registers.a + value) & negativeMask);
else
this->_registers.p.v = false;
this->_registers.a += value;
if (this->_isEmulationMode)
this->_registers.a %= 0x100;
this->_registers.p.z = this->_registers.a == 0;
this->_registers.p.n = this->_registers.a & negativeMask;
return (0);
}
}