MCUME/MCUME_teensy/teensynofrendo/nes6502.h

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4.5 KiB
C
Executable File

/*
** 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 2001/04/27 14:37:11 neil Exp $
*/
/* NOTE: 16-bit addresses avoided like the plague: use 32-bit values
** wherever humanly possible
*/
#ifndef _NES6502_H_
#define _NES6502_H_
#include "noftypes.h"
/* Define this to enable decimal mode in ADC / SBC (not needed in NES) */
/*#define NES6502_DECIMAL*/
#define NES6502_NUMBANKS 16
#define NES6502_BANKSHIFT 12
#define NES6502_BANKSIZE (0x10000 / NES6502_NUMBANKS)
#define NES6502_BANKMASK (NES6502_BANKSIZE - 1)
/* 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 */
nes6502_memread *read_handler;
nes6502_memwrite *write_handler;
uint32 pc_reg;
uint8 a_reg, p_reg;
uint8 x_reg, y_reg;
uint8 s_reg;
uint8 jammed; /* is processor jammed? */
uint8 int_pending, int_latency;
int32 total_cycles, burn_cycles;
} nes6502_context;
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/* Functions which govern the 6502's execution */
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(bool reset_flag);
extern void nes6502_burn(int cycles);
extern void nes6502_release(void);
/* 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 2001/04/27 14:37:11 neil
** wheeee
**
** Revision 1.1 2001/04/27 12:54:39 neil
** blah
**
** Revision 1.1.1.1 2001/04/27 07:03:54 neil
** initial
**
** Revision 1.17 2000/11/13 00:57:39 matt
** trying to add 1-instruction interrupt latency... and failing.
**
** Revision 1.16 2000/10/27 12:53:36 matt
** banks are always 4kB now
**
** Revision 1.15 2000/10/10 13:58:14 matt
** stroustrup squeezing his way in the door
**
** Revision 1.14 2000/09/15 03:42:32 matt
** nes6502_release to release current timeslice
**
** Revision 1.13 2000/09/11 03:55:32 matt
** cosmetics
**
** Revision 1.12 2000/09/08 11:54:48 matt
** optimize
**
** Revision 1.11 2000/09/07 21:58:18 matt
** api change for nes6502_burn, optimized core
**
** Revision 1.10 2000/09/07 01:34:55 matt
** nes6502_init deprecated, moved flag regs to separate vars
**
** Revision 1.9 2000/08/28 12:53:44 matt
** fixes for disassembler
**
** Revision 1.8 2000/08/28 01:46:15 matt
** moved some of them defines around, cleaned up jamming code
**
** Revision 1.7 2000/08/16 04:56:37 matt
** accurate CPU jamming, added dead page emulation
**
** Revision 1.6 2000/07/30 04:32:00 matt
** now emulates the NES frame IRQ
**
** Revision 1.5 2000/07/17 01:52:28 matt
** made sure last line of all source files is a newline
**
** Revision 1.4 2000/06/09 15:12:25 matt
** initial revision
**
*/