apple2ix/src/cpu.h
2013-06-11 00:08:15 -07:00

132 lines
3.7 KiB
C

/*
* Apple // emulator for Linux: Virtual 6502/65C02 interface
*
* Copyright 1994 Alexander Jean-Claude Bottema
* Copyright 1995 Stephen Lee
* Copyright 1997, 1998 Aaron Culliney
* Copyright 1998, 1999, 2000 Michael Deutschmann
*
* This software package is subject to the GNU General Public License
* version 2 or later (your choice) as published by the Free Software
* Foundation.
*
* THERE ARE NO WARRANTIES WHATSOEVER.
*
*/
#ifndef __ASSEMBLER__
#include <sys/types.h>
/* types */
typedef void *WMEM;
typedef void *RMEM;
struct memory_vector
{
RMEM r;
WMEM w;
};
struct cpu65_state
{
u_int16_t pc; /* Program counter */
u_int8_t a; /* Accumulator */
u_int8_t f; /* Flags (order not same as in real 6502) */
u_int8_t x,y; /* Index register */
u_int8_t sp; /* Stack Pointer */
};
struct cpu65_extra /* for debugging */
{
u_int16_t ea; /* Last effective address */
u_int8_t d; /* Last data byte written */
u_int8_t op; /* 1 = read occured, 2 = write, 3 = both */
};
/* 6502 CPU models */
#define CPU65_NMOS 0x0
#define CPU65_C02 0x1
#define CPU65_FAULT 0x100 /* Undoc. opcodes are BRK */
#define CPU65_SYNCHRO 0x200 /* Synchronize speed, not imp. */
/* Set up the processor for a new run. Sets up opcode table.
*/
extern void cpu65_set(int flags);
/* Interrupt the processor */
extern void cpu65_interrupt(int reason);
extern void cpu65_run(void);
extern void cpu65_step(void);
extern void cpu65_direct_write(int ea,int data);
extern struct memory_vector cpu65_vmem[65536];
extern struct cpu65_state cpu65_current;
extern struct cpu65_extra cpu65_debug;
extern unsigned char cpu65_flags_encode[256];
extern unsigned char cpu65_flags_decode[256];
extern unsigned int cpu65_delay;
#endif /* !__ASSEMBLER__ */
#define RebootSig 0x01
#define ResetSig 0x02
#define DebugStepSig 0x04
#define EnterDebugSig 0x08
/* Note: These are *not* the bit positions used for the flags in the P
* register of a real 6502. Rather, they have been distorted so that C,
* N and Z match the analogous flags in the _80386_ flags register.
*
* Additionally, V matches the position of the overflow flag in the high byte
* of the 80386 register.
*
*/
#define C_Flag 0x1 /* 6502 Carry */
#define X_Flag 0x2 /* 6502 Xtra */
#define I_Flag 0x4 /* 6502 Interrupt disable */
#define V_Flag 0x8 /* 6502 Overflow */
#define B_Flag 0x10 /* 6502 Break */
#define D_Flag 0x20 /* 6502 Decimal mode */
#define Z_Flag 0x40 /* 6502 Zero */
#define N_Flag 0x80 /* 6502 Neg */
#define C_Flag_Bit 8 /* 6502 Carry */
#define X_Flag_Bit 9 /* 6502 Xtra */
#define I_Flag_Bit 10 /* 6502 Interrupt disable */
#define V_Flag_Bit 11 /* 6502 Overflow */
#define B_Flag_Bit 12 /* 6502 Break */
#define D_Flag_Bit 13 /* 6502 Decimal mode */
#define Z_Flag_Bit 14 /* 6502 Zero */
#define N_Flag_Bit 15 /* 6502 Neg */
#define X_Reg %bl /* 6502 X register in %bl */
#define Y_Reg %bh /* 6502 Y register in %bh */
#define A_Reg %cl /* 6502 A register in %cl */
#define F_Reg %ch /* 6502 flags in %ch */
#define FF_Reg %ecx /* 6502 flags for bt */
#define SP_Reg %edx /* 6502 Stack pointer */
#define SP_Reg_L %dl /* 6502 Stack pointer low */
#define SP_Reg_H %dh /* 6502 Stack pointer high */
#define PC_Reg %si /* 6502 Program Counter */
#define PC_Reg_E %esi /* 6502 Program Counter */
#define EffectiveAddr %di /* Effective address */
#define EffectiveAddr_E %edi /* Effective address */
#ifndef __ASSEMBLER__
/* Private data. */
extern void *cpu65__opcodes[256];
extern void *const cpu65__nmos[256];
extern void *const cpu65__nmosbrk[256];
extern void *const cpu65__cmos[256];
extern unsigned char cpu65__signal;
#endif /* !__ASSEMBLER__ */