/* Header file for the instruction set simulator.
   Copyright (C) 1995  Frank D. Cringle.

This file is part of yaze - yet another Z80 emulator.

Yaze is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */

#include <limits.h>

#if UCHAR_MAX == 255
typedef unsigned char	BYTE;
#else
#error Need to find an 8-bit type for BYTE
#endif

#if USHRT_MAX == 65535
typedef unsigned short	WORD;
#else
#error Need to find an 16-bit type for WORD
#endif

/* FASTREG needs to be at least 16 bits wide and efficient for the
   host architecture */
#if UINT_MAX >= 65535
typedef unsigned int	FASTREG;
#else
typedef unsigned long	FASTREG;
#endif

/* FASTWORK needs to be wider than 16 bits and efficient for the host
   architecture */
#if UINT_MAX > 65535
typedef unsigned int	FASTWORK;
#else
typedef unsigned long	FASTWORK;
#endif

/* two sets of accumulator / flags */
extern WORD af[2];
extern int af_sel;

/* two sets of 16-bit registers */
extern struct ddregs {
	WORD bc;
	WORD de;
	WORD hl;
} regs[2];
extern int regs_sel;

extern WORD ir;
extern WORD ix;
extern WORD iy;
extern WORD sp;
extern WORD pc;
extern WORD IFF;

#ifndef MEMSIZE
#define MEMSIZE 64
#endif
extern BYTE ram[MEMSIZE*1024];
#ifdef MMU
extern BYTE *pagetable[MEMSIZE/4];
#endif

#ifdef DEBUG
extern volatile int stopsim;
#endif

extern FASTWORK simz80(FASTREG PC, int, void (*)());

#define FLAG_C	1
#define FLAG_N	2
#define FLAG_P	4
#define FLAG_H	16
#define FLAG_Z	64
#define FLAG_S	128

#define SETFLAG(f,c)	AF = (c) ? AF | FLAG_ ## f : AF & ~FLAG_ ## f
#define TSTFLAG(f)	((AF & FLAG_ ## f) != 0)

#define ldig(x)		((x) & 0xf)
#define hdig(x)		(((x)>>4)&0xf)
#define lreg(x)		((x)&0xff)
#define hreg(x)		(((x)>>8)&0xff)

#define Setlreg(x, v)	x = (((x)&0xff00) | ((v)&0xff))
#define Sethreg(x, v)	x = (((x)&0xff) | (((v)&0xff) << 8))

#ifdef MMU
#define RAM(a)		*(pagetable[((a)&0xffff)>>12]+((a)&0x0fff))
#else
#define RAM(a)		ram[(a)&0xffff]
#endif
#define GetBYTE(a)	RAM(a)

/* Fast write inside [3K; 64K-8K] 

   NOTICE: This is dependent on the assumption that the 8KB Basic ROM
   is present
*/

void slow_write(unsigned int a, unsigned char v);
#define PutBYTE(a,v) \
   do { \
     if (((a + 8192) & 0xFFFF) > 11*1024) \
       RAM(a) = v; \
     else \
       slow_write(a,v); \
   } while (0)

/*#define PutBYTE(a, v)	RAM(a) = v*/

#define GetWORD(a)	(RAM(a) | (RAM((a)+1) << 8))
#define PutWORD(a, v)							\
    do { PutBYTE(a, ((int)(v)&255));					\
	 PutBYTE((a)+1, (v) >> 8);					\
     } while (0)

#ifndef BIOS
extern int in(unsigned int);
extern void out(unsigned int, unsigned char);
#define Input(port) in(port)
#define Output(port, value) out(port,value)
#else
/* Define these as macros or functions if you really want to simulate I/O */
#define Input(port)	0
#define Output(port, value)
#endif