z80.h

ESS3890+SL原代码（1*16内存）

/* Copyright 2001, ESS Technology, Inc.     
/* SCCSID @(#)z80.h	1.4 12/07/01 */


/*
 * $Log$
 */

/** VGB: portable GameBoy emulator ***************************/
/**                                                         **/
/**                           Z80.h                         **/
/**                                                         **/
/** This file contains declarations relevant to emulation   **/
/** of Z80 CPU. See GB.h for #defines related to drivers    **/
/** and GameBoy emulation.                                  **/
/**                                                         **/
/** Copyright (C) Marat Fayzullin 1994-2001                 **/
/**     The contents of this file are property of Marat     **/
/**     Fayzullin and should only be used as agreed with    **/
/**     him. The file is confidential. Absolutely no        **/
/**     distribution allowed.                               **/
/*************************************************************/
#ifndef GBZ80_H
#define GBZ80_H

/* #define DEBUG */            /* Compile debugging version  */
/* #define LSB_FIRST */        /* Compile for low-endian CPU */
/* #define MSB_FIRST */        /* Compile for hi-endian CPU  */

                               /* LoopZ80() may return:      */
#define INT_VBLANK  0x01       /* VBlank interrupt           */
#define INT_LCD     0x02       /* LCD interrupt              */
#define INT_TIMER   0x04       /* Timer interrupt            */
#define INT_SERIAL  0x08       /* Serial I/O interrupt       */
#define INT_EXTERN  0x10       /* External interrupt         */
#define INT_ALL     0x1F       /* All interrupts             */
#define INT_NONE    0x00       /* No interrupts              */
#define INT_QUIT    0xE0       /* Exit the emulation         */

                               /* Interrupt vectors:         */
#define VEC_VBLANK  0x0040     /* VBlank interrupt           */
#define VEC_LCD     0x0048     /* LCD interrupt              */
#define VEC_TIMER   0x0050     /* Timer interrupt            */
#define VEC_SERIAL  0x0058     /* Serial I/O interrupt       */
#define VEC_EXTERN  0x0060     /* External interrupt         */

                               /* Bits in GBZ80 F register:  */
#define Z_FLAG      0x40       /* 1: Result is zero          */
#define H_FLAG      0x10       /* 1: Halfcarry/Halfborrow    */
#define P_FLAG      0x04       /* 1: Result is even          */
#define V_FLAG      0x04       /* 1: Overflow occured        */
#define N_FLAG      0x02       /* 1: Subtraction occured     */
#define C_FLAG      0x01       /* 1: Carry/Borrow occured    */

/** Simple Datatypes *****************************************/
/** NOTICE: sizeof(byte)=1 and sizeof(word)=2               **/
/*************************************************************/
#ifndef BYTE_TYPE_DEFINED
#define BYTE_TYPE_DEFINED
typedef unsigned char byte;
#endif
#ifndef WORD_TYPE_DEFINED
#define WORD_TYPE_DEFINED
typedef unsigned short word;
#endif

/** Structured Datatypes *************************************/
/** NOTICE: #define LSB_FIRST for machines where least      **/
/**         signifcant byte goes first.                     **/
/*************************************************************/
typedef union
{
#ifdef LSB_FIRST
  struct { byte l,h; } B;
#else
  struct { byte h,l; } B;
#endif
  word W;
} pair;

typedef struct
{
  pair AF,BC,DE,HL,IX,IY,SP;       /* Main registers      */
  int IFF,I;                         /* Interrupt registers */

  int  IPeriod;       /* Set IPeriod to number of CPU cycles */
                      /* between calls to LoopZ80()          */
  int  ICount;        /* Number of cycles to next LoopZ80()  */
  int  IBackup;       /* Private, don't touch                */
  int IRQs;          /* Set bits for pending IRQs           */
} GBZ80;

/** ResetZ80() ***********************************************/
/** This function can be used to reset the registers before **/
/** starting execution with RunZ80(). It sets registers to  **/
/** their initial values.                                   **/
/*************************************************************/
void ResetZ80(register GBZ80 *R);
  
/** ExecZ80() ************************************************/
/** This function will execute a single Z80 opcode. It will **/
/** then return next PC, and current register values in R.  **/
/*************************************************************/
#ifndef GAMEBOY
word ExecZ80(register GBZ80 *R);
#endif

/** IntZ80() *************************************************/
/** This function will call the next pending interrupt      **/
/** based on priority.                                      **/
/*************************************************************/
void IntZ80(register GBZ80 *R);

/** RunZ80() *************************************************/
/** This function will run Z80 code until an LoopZ80() call **/
/** returns INT_QUIT. It will return the PC at which        **/
/** emulation stopped, and current register values in R.    **/
/*************************************************************/
word RunZ80(register GBZ80 *R);

/** RdZ80()/WrZ80() ******************************************/
/** These functions are called when access to RAM occurs.   **/
/** They allow to control memory access.                    **/
/************************************ TO BE WRITTEN BY USER **/
void WrZ80(register int Addr,register int Value);
int RdZ80(register int Addr);

/** DebugZ80() ***********************************************/
/** This function should exist if DEBUG is #defined. When   **/
/** Trace!=0, it is called after each command executed by   **/
/** the CPU, and given the Z80 registers. Emulation exits   **/
/** if DebugZ80() returns 0.                                **/
/*************************************************************/

/** LoopZ80() ************************************************/
/** Z80 emulation calls this function periodically to check **/
/** if the system hardware requires any interrupts. This    **/
/** function must return one or more ORed interrupt bits    **/
/** (INT_VBLANK, INT_LCD, etc.) or INT_NONE for no intrpts. **/
/** Return INT_QUIT to exit the emulation loop.             **/
/************************************ TO BE WRITTEN BY USER **/
int LoopZ80(register GBZ80 *R);

#endif /* GBZ80_H */