#ifndef MAIN_H
#define MAIN_H

#include <stdint.h>

#define MEMORY_MAX (1 << 16)
#define PC_START 0x3000

typedef uint16_t u16;

// registers
enum {
  R_R0 = 0,
  R_R1,
  R_R2,
  R_R3,
  R_R4,
  R_R5,
  R_R6,
  R_R7,
  R_R8,
  R_PC,
  R_COND,
  R_COUNT
};


// cond flags
enum {
  FL_POS = 1 << 0,
  FL_ZRO = 1 << 1,
  FL_NEG = 1 << 2,
};

// memory mapped registers
enum {
  MR_KBSR = 0xFE00, /* address of these registers in memory */
  MR_KBDR = 0xFE02,
};

// Global variables
static u16 memory[MEMORY_MAX];
static u16 reg[R_COUNT];
static u16 running;

u16 sign_extend(u16 x, int bit_count);
void update_flags(u16 r);
void mem_write(u16 address, u16 value);
u16 mem_read(u16 address);

#endif