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Cyclone.h
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1 
2 // Cyclone 68000 Emulator - Header File
3 
4 // Copyright (c) 2004,2011 FinalDave (emudave (at) gmail.com)
5 // Copyright (c) 2005-2011 GraÅžvydas "notaz" Ignotas (notasas (at) gmail.com)
6 
7 // This code is licensed under the GNU General Public License version 2.0 and the MAME License.
8 // You can choose the license that has the most advantages for you.
9 
10 // SVN repository can be found at http://code.google.com/p/cyclone68000/
11 
12 
13 #ifndef __CYCLONE_H__
14 #define __CYCLONE_H__
15 
16 #ifdef __cplusplus
17 extern "C" {
18 #endif
19 
20 extern int CycloneVer; // Version number of library
21 
22 struct Cyclone
23 {
24  unsigned int d[8]; // [r7,#0x00]
25  unsigned int a[8]; // [r7,#0x20]
26  unsigned int pc; // [r7,#0x40] Memory Base (.membase) + 68k PC
27  unsigned char srh; // [r7,#0x44] Status Register high (T_S__III)
28  unsigned char unused; // [r7,#0x45] Unused
29  unsigned char flags; // [r7,#0x46] Flags (ARM order: ____NZCV) [68k order is XNZVC]
30  unsigned char irq; // [r7,#0x47] IRQ level
31  unsigned int osp; // [r7,#0x48] Other Stack Pointer (USP/SSP)
32  unsigned int xc; // [r7,#0x4c] Extend flag (bit29: ??X? _)
33  unsigned int prev_pc; // [r7,#0x50] Set to start address of currently executed opcode + 2 (if enabled in config.h)
34  unsigned int jumptab; // [r7,#0x54] Jump table pointer
35  int state_flags; // [r7,#0x58] bit: 0: stopped state, 1: trace state, 2: activity bit, 3: addr error, 4: fatal halt
36  int cycles; // [r7,#0x5c] Number of cycles to execute - 1. Updates to cycles left after CycloneRun()
37  int membase; // [r7,#0x60] Memory Base (ARM address minus 68000 address)
38  unsigned int (*checkpc)(unsigned int pc); // [r7,#0x64] called to recalc Memory Base+pc
39  unsigned int (*read8 )(unsigned int a); // [r7,#0x68]
40  unsigned int (*read16 )(unsigned int a); // [r7,#0x6c]
41  unsigned int (*read32 )(unsigned int a); // [r7,#0x70]
42  void (*write8 )(unsigned int a,unsigned char d); // [r7,#0x74]
43  void (*write16)(unsigned int a,unsigned short d); // [r7,#0x78]
44  void (*write32)(unsigned int a,unsigned int d); // [r7,#0x7c]
45  unsigned int (*fetch8 )(unsigned int a); // [r7,#0x80]
46  unsigned int (*fetch16)(unsigned int a); // [r7,#0x84]
47  unsigned int (*fetch32)(unsigned int a); // [r7,#0x88]
48  int (*IrqCallback)(int int_level); // [r7,#0x8c] optional irq callback function, see config.h
49  void (*ResetCallback)(void); // [r7,#0x90] if enabled in config.h, calls this whenever RESET opcode is encountered.
50  int (*UnrecognizedCallback)(void); // [r7,#0x94] if enabled in config.h, calls this whenever unrecognized opcode is encountered.
51  unsigned int internal[6]; // [r7,#0x98] reserved for internal use, do not change.
52 };
53 
54 // Initialize. Used only if Cyclone was compiled with compressed jumptable, see config.h
55 void CycloneInit(void);
56 
57 // Reset
58 void CycloneReset(struct Cyclone *pcy);
59 
60 // Run cyclone. Cycles should be specified in context (pcy->cycles)
61 void CycloneRun(struct Cyclone *pcy);
62 
63 // Utility functions to get and set SR
64 void CycloneSetSr(struct Cyclone *pcy, unsigned int sr);
65 unsigned int CycloneGetSr(const struct Cyclone *pcy);
66 
67 // Generates irq exception if needed (if pcy->irq > mask).
68 // Returns cycles used for exception if it was generated, 0 otherwise.
69 int CycloneFlushIrq(struct Cyclone *pcy);
70 
71 // Functions for saving and restoring state.
72 // CycloneUnpack() uses checkpc(), so it must be initialized.
73 // save_buffer must point to buffer of 128 (0x80) bytes of size.
74 void CyclonePack(const struct Cyclone *pcy, void *save_buffer);
75 void CycloneUnpack(struct Cyclone *pcy, const void *save_buffer);
76 
77 // genesis: if 1, switch to normal TAS handlers
78 void CycloneSetRealTAS(int use_real);
79 
80 
81 // These values are special return values for IrqCallback.
82 
83 // Causes an interrupt autovector (0x18 + interrupt level) to be taken.
84 // This happens in a real 68K if VPA or AVEC is asserted during an interrupt
85 // acknowledge cycle instead of DTACK (the most common situation).
86 #define CYCLONE_INT_ACK_AUTOVECTOR -1
87 
88 // Causes the spurious interrupt vector (0x18) to be taken
89 // This happens in a real 68K if BERR is asserted during the interrupt
90 // acknowledge cycle (i.e. no devices responded to the acknowledge).
91 #define CYCLONE_INT_ACK_SPURIOUS -2
92 
93 
94 #ifdef __cplusplus
95 } // End of extern "C"
96 #endif
97 
98 #endif // __CYCLONE_H__
99