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/*
** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
**
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of version 2 of the GNU Library General
** Public License as published by the Free Software Foundation.
**
** 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
** Library General Public License for more details. To obtain a
** copy of the GNU Library General Public License, write to the Free
** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Any permitted reproduction of these routines, in whole or in part,
** must bear this legend.
**
**
** nes6502.h
**
** NES custom 6502 CPU definitions / prototypes
** $Id: nes6502.h,v 1.2 2003/12/05 15:55:01 f1rmb Exp $
*/
/* straitm */
#include "types.h"
/* NOTE: 16-bit addresses avoided like the plague: use 32-bit values
** wherever humanly possible
*/
#ifndef _NES6502_H_
#define _NES6502_H_
/* Define this to enable decimal mode in ADC / SBC (not needed in NES) */
/*#define NES6502_DECIMAL*/
/* number of bank pointers the CPU emulation core handles */
#ifdef NSF_PLAYER
#define NES6502_4KBANKS
#endif
#ifdef NES6502_4KBANKS
#define NES6502_NUMBANKS 16
#define NES6502_BANKSHIFT 12
#else
#define NES6502_NUMBANKS 8
#define NES6502_BANKSHIFT 13
#endif
#define NES6502_BANKMASK ((0x10000 / NES6502_NUMBANKS) - 1)
/* Add memory access control flags. This is a ram shadow memory that holds
* for each memory bytes access flags for read, write and execute access.
* The nes6502_mem_access holds all new access (all mode all location). It is
* used to determine if the player has loop in playing time calculation.
*/
#ifdef NES6502_MEM_ACCESS_CTRL
extern uint8 nes6502_mem_access;
# define NES6502_READ_ACCESS 1
# define NES6502_WRITE_ACCESS 2
# define NES6502_EXE_ACCESS 4
#endif /* #ifdef NES6502_MEM_ACCESS_CTRL */
/* P (flag) register bitmasks */
#define N_FLAG 0x80
#define V_FLAG 0x40
#define R_FLAG 0x20 /* Reserved, always 1 */
#define B_FLAG 0x10
#define D_FLAG 0x08
#define I_FLAG 0x04
#define Z_FLAG 0x02
#define C_FLAG 0x01
/* Vector addresses */
#define NMI_VECTOR 0xFFFA
#define RESET_VECTOR 0xFFFC
#define IRQ_VECTOR 0xFFFE
/* cycle counts for interrupts */
#define INT_CYCLES 7
#define RESET_CYCLES 6
#define NMI_MASK 0x01
#define IRQ_MASK 0x02
/* Stack is located on 6502 page 1 */
#define STACK_OFFSET 0x0100
typedef struct
{
uint32 min_range, max_range;
uint8 (*read_func)(uint32 address);
} nes6502_memread;
typedef struct
{
uint32 min_range, max_range;
void (*write_func)(uint32 address, uint8 value);
} nes6502_memwrite;
typedef struct
{
uint8 * mem_page[NES6502_NUMBANKS]; /* memory page pointers */
#ifdef NES6502_MEM_ACCESS_CTRL
uint8 * acc_mem_page[NES6502_NUMBANKS]; /* memory access page pointer */
#endif
nes6502_memread *read_handler;
nes6502_memwrite *write_handler;
int dma_cycles;
uint32 pc_reg;
uint8 a_reg, p_reg, x_reg, y_reg, s_reg;
uint8 int_pending;
} nes6502_context;
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/* Functions which govern the 6502's execution */
extern void nes6502_init(void);
extern void nes6502_reset(void);
extern int nes6502_execute(int total_cycles);
extern void nes6502_nmi(void);
extern void nes6502_irq(void);
extern uint8 nes6502_getbyte(uint32 address);
extern uint32 nes6502_getcycles(boolean reset_flag);
extern void nes6502_setdma(int cycles);
#ifdef NES6502_MEM_ACCESS_CTRL
extern void nes6502_chk_mem_access(uint8 * access, int flags);
#else
#define nes6502_chk_mem_access(access,flags)
#endif
/* Context get/set */
extern void nes6502_setcontext(nes6502_context *cpu);
extern void nes6502_getcontext(nes6502_context *cpu);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _NES6502_H_ */
/*
** $Log: nes6502.h,v $
** Revision 1.2 2003/12/05 15:55:01 f1rmb
** cleanup phase II. use xprintf when it's relevant, use xine_xmalloc when it's relevant too. Small other little fix (can't remember). Change few internal function prototype because it xine_t pointer need to be used if some xine's internal sections. NOTE: libdvd{nav,read} is still too noisy, i will take a look to made it quit, without invasive changes. To be continued...
**
** Revision 1.1 2003/01/08 07:04:35 tmmm
** initial import of Nosefart sources
**
** Revision 1.4 2000/06/09 15:12:25 matt
** initial revision
**
*/
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