SimpleNES/include/CPU.h

#ifndef CPU_H
#define CPU_H
#include "CPUOpcodes.h"
#include "MainBus.h"

namespace sn
{

    class CPU
    {
        public:

            CPU(MainBus &mem);

            void step();
            void reset();
            void reset(Address start_addr);
            void log();

            Address getPC() { return r_PC; }
            void skipDMACycles();

            void interrupt(InterruptType type);

        private:
            void interruptSequence(InterruptType type);

            //Instructions are split into five sets to make decoding easier.
            //These functions return true if they succeed
            bool executeImplied(Byte opcode);
            bool executeBranch(Byte opcode);
            bool executeType0(Byte opcode);
            bool executeType1(Byte opcode);
            bool executeType2(Byte opcode);

            Address readAddress(Address addr);

            void pushStack(Byte value);
            Byte pullStack();

            //If a and b are in different pages, increases the m_SkipCycles by 1
            void skipPageCrossCycle(Address a, Address b);
            void setZN(Byte value);

            int m_skipCycles;
            int m_cycles;

            //Registers
            Address r_PC;
            Byte r_SP;
            Byte r_A;
            Byte r_X;
            Byte r_Y;

            //Status flags.
            //Is storing them in one byte better ?
            bool f_C;
            bool f_Z;
            bool f_I;
            bool f_D;
            bool f_V;
            bool f_N;

            bool m_pendingNMI;
            bool m_pendingIRQ;

            MainBus &m_bus;
    };

};
#endif // CPU_H