simz80.h

   1 /* Header file for the instruction set simulator.
   2    Copyright (C) 1995  Frank D. Cringle.
   3
   4 This file is part of yaze - yet another Z80 emulator.
   5
   6 Yaze is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 2 of the License, or (at your
   9 option) any later version.
  10
  11 This program is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
  19
  20 #include <limits.h>
  21
  22 #if UCHAR_MAX == 255
  23 typedef unsigned char   BYTE;
  24 #else
  25 #error Need to find an 8-bit type for BYTE
  26 #endif
  27
  28 #if USHRT_MAX == 65535
  29 typedef unsigned short  WORD;
  30 #else
  31 #error Need to find an 16-bit type for WORD
  32 #endif
  33
  34 /* FASTREG needs to be at least 16 bits wide and efficient for the
  35    host architecture */
  36 #if UINT_MAX >= 65535
  37 typedef unsigned int    FASTREG;
  38 #else
  39 typedef unsigned long   FASTREG;
  40 #endif
  41
  42 /* FASTWORK needs to be wider than 16 bits and efficient for the host
  43    architecture */
  44 #if UINT_MAX > 65535
  45 typedef unsigned int    FASTWORK;
  46 #else
  47 typedef unsigned long   FASTWORK;
  48 #endif
  49
  50 /* two sets of accumulator / flags */
  51 extern WORD af[2];
  52 extern int af_sel;
  53
  54 /* two sets of 16-bit registers */
  55 extern struct ddregs {
  56         WORD bc;
  57         WORD de;
  58         WORD hl;
  59 } regs[2];
  60 extern int regs_sel;
  61
  62 extern WORD ir;
  63 extern WORD ix;
  64 extern WORD iy;
  65 extern WORD sp;
  66 extern WORD pc;
  67 extern WORD IFF;
  68
  69 #ifndef MEMSIZE
  70 #define MEMSIZE 64
  71 #endif
  72 extern BYTE ram[MEMSIZE*1024];
  73 #ifdef MMU
  74 extern BYTE *pagetable[MEMSIZE/4];
  75 #endif
  76
  77 #ifdef DEBUG
  78 extern volatile int stopsim;
  79 #endif
  80
  81 extern FASTWORK simz80(FASTREG PC, int, int (*)());
  82
  83 #define FLAG_C  1
  84 #define FLAG_N  2
  85 #define FLAG_P  4
  86 #define FLAG_H  16
  87 #define FLAG_Z  64
  88 #define FLAG_S  128
  89
  90 #define SETFLAG(f,c)    AF = (c) ? AF | FLAG_ ## f : AF & ~FLAG_ ## f
  91 #define TSTFLAG(f)      ((AF & FLAG_ ## f) != 0)
  92
  93 #define ldig(x)         ((x) & 0xf)
  94 #define hdig(x)         (((x)>>4)&0xf)
  95 #define lreg(x)         ((x)&0xff)
  96 #define hreg(x)         (((x)>>8)&0xff)
  97
  98 #define Setlreg(x, v)   x = (((x)&0xff00) | ((v)&0xff))
  99 #define Sethreg(x, v)   x = (((x)&0xff) | (((v)&0xff) << 8))
 100
 101 #ifdef MMU
 102 #define RAM(a)          *(pagetable[((a)&0xffff)>>12]+((a)&0x0fff))
 103 #else
 104 #define RAM(a)          ram[(a)&0xffff]
 105 #endif
 106 #define GetBYTE(a)      RAM(a)
 107
 108 /* Fast write inside [3K; 64K-8K]
 109
 110    NOTICE: This is dependent on the assumption that the 8KB Basic ROM
 111    is present
 112 */
 113
 114 void slow_write(unsigned int a, unsigned char v);
 115 #define PutBYTE(a,v) \
 116    do { \
 117      if (((a + 8192) & 0xFFFF) > 11*1024) \
 118        RAM(a) = v; \
 119      else \
 120        slow_write(a,v); \
 121    } while (0)
 122
 123 /*#define PutBYTE(a, v) RAM(a) = v*/
 124
 125 #define GetWORD(a)      (RAM(a) | (RAM((a)+1) << 8))
 126 #define PutWORD(a, v)                                                   \
 127     do { PutBYTE(a, ((int)(v)&255));                                    \
 128          PutBYTE((a)+1, (v) >> 8);                                      \
 129      } while (0)
 130
 131 #ifndef BIOS
 132 extern int in(unsigned int);
 133 extern void out(unsigned int, unsigned char);
 134 #define Input(port) in(port)
 135 #define Output(port, value) out(port,value)
 136 #else
 137 /* Define these as macros or functions if you really want to simulate I/O */
 138 #define Input(port)     0
 139 #define Output(port, value)
 140 #endif