/*
 * $Id: cpu.h,v 1.4 1996/02/19 17:36:37 alex Exp alex $
 *
 * This file is part of Commodore 64 emulator.
 * See README for copyright notice
 *
 * This file contains useful stuff when you are creating
 * virtual machine like MCS6510 based microcomputer.
 *
 * Included are:
 *	o registers
 *	o flags in PSW
 *      o addressing modes
 *
 * Written by
 *   Vesa-Matti Puro (vmp@lut.fi)
 *   Jarkko Sonninen (sonninen@lut.fi)
 *   Jouko Valta (jopi@stekt.oulu.fi)
 *
 *
 * $Log: cpu.h,v $
 * Revision 1.4  1996/02/19 17:36:37  alex
 * Added init_cpu prototype
 *
 * Revision 1.3  1995/12/12 16:21:39  alex
 * Cleaned it up a bit.
 *
 * Revision 1.2  1995/11/26  21:52:43  alex
 * *** empty log message ***
 *
 * Revision 1.2  1994/12/12  16:59:44  jopi
 * Several changes in op table
 *
 * Revision 1.1  1994/06/16  17:19:26  jopi
 * Initial revision
 *
 *
 *
 */

#ifndef X64_CPU_H
#define X64_CPU_H


#include "config.h"
#include "types.h"

/* 6510 Registers. */
void init_cpu(ADDRESS addr);

#define AC		accumulator
#define XR		x_register
#define YR		y_register
#define SP		stack_pointer
#define PC		program_counter
#define PCH		((PC>>8)&0xff)
#define PCL		(PC&0xff)

#define ZF		zero_flag
#define SF		sign_flag
#define OF		overflow_flag
#define BF		break_flag
#define DF		decimal_flag
#define IF		interrupt_flag
#define CF		carry_flag


/* Masks which indicate location of status flags in PSW. */
#define S_SIGN		0x80
#define S_OVERFLOW	0x40
#define S_NOTUSED 	0x20
#define S_BREAK		0x10
#define S_DECIMAL	0x08
#define S_INTERRUPT	0x04
#define S_ZERO		0x02
#define S_CARRY		0x01


/* ADDRESSING MODES */

#define IMPLIED		0
#define ACCUMULATOR	1
#define IMMEDIATE	2

#define ZERO_PAGE	3
#define ZERO_PAGE_X	4
#define ZERO_PAGE_Y	5

#define ABSOLUTE	6
#define ABSOLUTE_X	7
#define ABSOLUTE_Y	8

#define ABS_INDIRECT	9
#define INDIRECT_X	10
#define INDIRECT_Y	11

#define RELATIVE	12

#define ASS_CODE	13



/*
 * Declaration for lookup-table which is used to translate MOS6502
 * machine instructions. Machine code is used as index to array called
 * lookup. Pointer to function is then fetched from array and function
 * is called.
 */

extern struct lookup_tag {
    char          *mnemonic;	/* Selfdocumenting? */
    short          addr_mode;
    unsigned char  source;
    unsigned char  destination;
    unsigned char  cycles;
    unsigned char  pbc_fix;	/* Cycle for Page Boundary Crossing */
}       lookup[];


/* Addressing mode (addr_mode) is used when instruction is diassembled
 * or assembled by diassembler or assembler. This is used i.e.
 * in function char *sprint_opcode() in the file misc.c.
 *
 * MOS6502 addressing modes are #defined in the file "vmachine.h".
 *
 * Mnemonic is character string telling the name of the instruction.
 */

#define M_NONE	0
#define M_AC 	1
#define M_XR	2
#define M_YR	3
#define M_SP	4
#define M_SR	5
#define M_PC	6
#define M_IMM	7
#define M_ZERO	8
#define M_ZERX	9
#define M_ZERY	10
#define M_ABS	11
#define M_ABSX	12
#define M_ABSY	13
#define M_AIND	14
#define M_INDX	15
#define M_INDY	16
#define M_REL	17
#define M_FC	18
#define M_FD	19
#define M_FI	20
#define M_FV	21
#define M_ADDR	22
#define M_	23

#ifndef NO_UNDOC_CMDS
#define M_ACIM	24	/* Source: AC & IMMED (bus collision) */
#define M_ANXR	25	/* Source: AC & XR (bus collision) */
#define M_AXIM	26	/* Source: (AC | #EE) & XR & IMMED (bus collision) */
#define M_ACNC	27	/* Dest: M_AC and Carry = Negative */
#define M_ACXR	28	/* Dest: M_AC, M_XR */

#define M_SABY	29	/* Source: (ABS_Y & SP) (bus collision) */
#define M_ACXS	30	/* Dest: M_AC, M_XR, M_SP */
#define M_STH0	31	/* Dest: Store (src & Addr_Hi+1) to (Addr +0x100) */
#define M_STH1	32
#define M_STH2	33
#define M_STH3	34

#else
#define M_ACIM	M_NONE
#define M_ANXR	M_NONE
#define M_AXIM	M_NONE
#define M_ACNC	M_NONE
#define M_ACXR	M_NONE

#define M_SABY	M_NONE
#define M_ACXS	M_NONE
#define M_STH0	M_NONE
#define M_STH1	M_NONE
#define M_STH2	M_NONE
#define M_STH3	M_NONE
#endif



#endif  /* X64_CPU_H */