nes6502.h

   1 #ifndef __NES6502_H
   2 #define __NES6502_H
   3
   4 #include "types.h"
   5
   6 #define  NES6502_NUMBANKS  16
   7 #define  NES6502_BANKSHIFT 12
   8 #define  NES6502_BANKSIZE  (0x10000 / NES6502_NUMBANKS)
   9 #define  NES6502_BANKMASK  (NES6502_BANKSIZE - 1)
  10
  11 /* Stack base address (page 1) */
  12 #define NES6502_STACK_OFFSET 0x100
  13
  14 /* Vector addresses */
  15 #define NES6502_NMI_VECTOR     0xFFFA
  16 #define NES6502_RESET_VECTOR   0xFFFC
  17 #define NES6502_IRQ_VECTOR     0xFFFE
  18
  19 /* cycle counts for interrupts */
  20 #define NES6502_INT_CYCLES   7
  21 #define NES6502_RESET_CYCLES 6
  22
  23
  24 /* P (flag) register bitmasks */
  25 #define NES6502_C_FLAG      1
  26 #define NES6502_Z_FLAG      2
  27 #define NES6502_I_FLAG      4
  28 #define NES6502_D_FLAG      8
  29 #define NES6502_B_FLAG     16
  30 #define NES6502_R_FLAG     32
  31 #define NES6502_V_FLAG     64
  32 #define NES6502_N_FLAG    128
  33
  34 typedef struct
  35 {
  36    uint32 min_range, max_range;
  37    uint8 (*read_func) (uint32 address);
  38 } nes6502_memread;
  39
  40 typedef struct
  41 {
  42    uint32 min_range, max_range;
  43    void (*write_func) (uint32 address, uint8 value);
  44 } nes6502_memwrite;
  45
  46 #ifdef DEBUGGER_ENABLED
  47 #define NES6502_MAX_BREAKPOINTS     8
  48 #define NES6502_DEBUG_READ          1
  49 #define NES6502_DEBUG_WRITE         2
  50 #define NES6502_DEBUG_DISABLED    128
  51 typedef void (*nes6502_debugf) (int first_insn);
  52 #endif
  53
  54 typedef struct
  55 {
  56    uint8 *mem_page[NES6502_NUMBANKS];  /* memory page pointers */
  57
  58    nes6502_memread *read_handler;
  59    nes6502_memwrite *write_handler;
  60
  61    uint32 pc_reg;
  62    uint32 a_reg, p_reg;
  63    uint32 x_reg, y_reg;
  64    uint32 s_reg;
  65
  66    int32 total_cycles;
  67    int32 remaining_cycles;
  68    int32 burn_cycles;
  69
  70    int halted;
  71    int int_pending;
  72
  73 #ifdef DEBUGGER_ENABLED
  74    nes6502_debugf debug_handler;
  75
  76    uint32 num_bp;
  77    uint32 bp_addr[NES6502_MAX_BREAKPOINTS];
  78    uint32 bp_mask[NES6502_MAX_BREAKPOINTS];
  79    int32 bp_flags[NES6502_MAX_BREAKPOINTS];
  80
  81 #endif
  82 } nes6502_context;
  83
  84
  85
  86 void nes6502_power (void);
  87 void nes6502_reset (void);
  88 void nes6502_halt (void);
  89 int nes6502_ishalted (void);
  90 int32 nes6502_execute (int32 cycles);
  91
  92 uint8 nes6502_readbyte (uint32 address);
  93 void nes6502_writebyte (uint32 address, uint8 value);
  94 uint8 nes6502_getbyte (uint32 address);
  95 void nes6502_putbyte (uint32 address, uint8 value);
  96
  97 void nes6502_nmi (void);
  98 void nes6502_irq (void);
  99 void nes6502_burn (int32 cycles);
 100 void nes6502_release (void);
 101
 102 void nes6502_setcontext (nes6502_context *cpu);
 103 void nes6502_getcontext (nes6502_context *cpu);
 104
 105 #ifdef DEBUGGER_ENABLED
 106 int nes6502_addbreakpoint (uint32 address, uint32 mask, int32 flags);
 107 void nes6502_editbreakpoint (uint32 bp, uint32 address, uint32 mask, int32 flags);
 108 void nes6502_getbreakpoint (uint32 bp, uint32 *address, uint32 *mask, int32 *flags);
 109 void nes6502_removebreakpoint (uint32 bp);
 110 uint32 nes6502_numbreakpoints (void);
 111 #endif
 112
 113 #endif /* __NES6502_H */