nesemu/include/system.h

//
// Created by william on 12/23/23.
//

#include "types.h"
#include "mapper.h"
#include "ppu.h"

#ifndef NESEMULATOR_SYSTEM_H
#define NESEMULATOR_SYSTEM_H

// NTSC NES Master Clock (~21.47 MHz)
#define MASTER_CLOCK 21477272
#define CPU_CLOCK_DIVISOR 12
#define PPU_CLOCK_DIVISOR 4
#define FRAME_RATE 60

#define PPU_REGISTERS_BASE_ADDR 0x2000
#define PPU_REGISTER_OAM_DMA_ADDR 0x4014
#define APU_REGISTERS_COUNT 24

// Reference: https://www.nesdev.org/obelisk-6502-guide/registers.html
typedef struct cpu {
    address program_counter;
    byte stack_pointer;
    byte accumulator;
    byte x;
    byte y;
    byte status;
    bool oam_dma_triggered;
    bool nmi_requested;
} CPU;

typedef struct system {
    void *rom_header;
    CPU cpu;
    PPU ppu;
    Mapper mapper;
    ram ram;
    byte apu_registers[APU_REGISTERS_COUNT];
    unsigned long cycle_count;
} System;

/**
 * Initialize all components of a system.
 *
 * @param system The system to initialize
 */
void system_init(System *system);

void system_start(System *system);

/**
 * Starts the main loop of a system.
 *
 * @param system The system
 */
void system_loop(System *system);

/**
 * De-initialize the components of a system.
 *
 * @param system The system to de-initialize
 */
void system_uninit(System *system);

#endif //NESEMULATOR_SYSTEM_H