/* Author      : Rick van der Zwet
 * S-number    : 0433373
 * Version     : $Id: datapath.h 366 2007-12-04 18:29:07Z rick $
 * Copyright   : FreeBSD Licence
 * Description : Memory unit header
 */

#ifndef DATAPATH_H
#define DATAPATH_H

#include "sim.h"
#include "alu.h"
#include "constant.h"
#include "imm.h"
#include "memory.h"


typedef enum { NO_COMPONENT, A, B, TEMP, TEMP2, PC, MAR, MDR, CONST, 
               IMM } sx_control_t;
typedef enum { DATAPATH, MEMORY } mux_control_t;
typedef enum { READONLY, WRITE } buffer_control_t;
typedef enum { R_A=1, R_B, R_AB, W_C, R_AxW_C, R_BxW_C, 
               R_ABxW_C } register_control_t;

/* XXX: Not that effient, might be the use of bitfields */
typedef struct {
    sx_control_t s1;
    sx_control_t s2;
    mux_control_t mux;
    const_control_t constant;
    imm_control_t imm;
    alu_control_t alu_unit;
    mem_control_t memory;
    buffer_control_t a;
    buffer_control_t b;
    buffer_control_t c;
    buffer_control_t temp;
    buffer_control_t temp2;
    buffer_control_t pc;
    buffer_control_t mar;
    buffer_control_t mdr;
    buffer_control_t ir;
    register_control_t reg;
    address_t register_address_a;
    address_t register_address_b;
    address_t register_address_c;
} control_t;

word a;
word b;
word c;
word temp;
word temp2;
word pc;
word mar;
word mdr;
word ir;
word imm;
word constant;

word reg[32];
word select_sx(const sx_control_t control);
void update_state(control_t control);

#endif