1 | /*****************************************************************************/ |
2 | /* */ |
3 | /* 6502.h */ |
4 | /* */ |
5 | /* CPU core for the 6502 */ |
6 | /* */ |
7 | /* */ |
8 | /* */ |
9 | /* (C) 2003-2012, Ullrich von Bassewitz */ |
10 | /* Roemerstrasse 52 */ |
11 | /* D-70794 Filderstadt */ |
12 | /* EMail: uz@cc65.org */ |
13 | /* */ |
14 | /* */ |
15 | /* This software is provided 'as-is', without any expressed or implied */ |
16 | /* warranty. In no event will the authors be held liable for any damages */ |
17 | /* arising from the use of this software. */ |
18 | /* */ |
19 | /* Permission is granted to anyone to use this software for any purpose, */ |
20 | /* including commercial applications, and to alter it and redistribute it */ |
21 | /* freely, subject to the following restrictions: */ |
22 | /* */ |
23 | /* 1. The origin of this software must not be misrepresented; you must not */ |
24 | /* claim that you wrote the original software. If you use this software */ |
25 | /* in a product, an acknowledgment in the product documentation would be */ |
26 | /* appreciated but is not required. */ |
27 | /* 2. Altered source versions must be plainly marked as such, and must not */ |
28 | /* be misrepresented as being the original software. */ |
29 | /* 3. This notice may not be removed or altered from any source */ |
30 | /* distribution. */ |
31 | /* */ |
32 | /*****************************************************************************/ |
33 | |
34 | |
35 | |
36 | #ifndef _6502_H |
37 | #define _6502_H |
38 | |
39 | |
40 | |
41 | /*****************************************************************************/ |
42 | /* Data */ |
43 | /*****************************************************************************/ |
44 | |
45 | |
46 | |
47 | /* Supported CPUs */ |
48 | typedef enum CPUType { |
49 | CPU_6502, |
50 | CPU_65C02 |
51 | } CPUType; |
52 | |
53 | /* Current CPU */ |
54 | extern CPUType CPU; |
55 | |
56 | /* 6502 CPU registers */ |
57 | typedef struct CPURegs CPURegs; |
58 | struct CPURegs { |
59 | unsigned AC; /* Accumulator */ |
60 | unsigned XR; /* X register */ |
61 | unsigned YR; /* Y register */ |
62 | unsigned ZR; /* Z register */ |
63 | unsigned SR; /* Status register */ |
64 | unsigned SP; /* Stackpointer */ |
65 | unsigned PC; /* Program counter */ |
66 | }; |
67 | |
68 | /* Status register bits */ |
69 | #define CF 0x01 /* Carry flag */ |
70 | #define ZF 0x02 /* Zero flag */ |
71 | #define IF 0x04 /* Interrupt flag */ |
72 | #define DF 0x08 /* Decimal flag */ |
73 | #define BF 0x10 /* Break flag */ |
74 | #define OF 0x40 /* Overflow flag */ |
75 | #define SF 0x80 /* Sign flag */ |
76 | |
77 | |
78 | |
79 | /*****************************************************************************/ |
80 | /* Code */ |
81 | /*****************************************************************************/ |
82 | |
83 | |
84 | |
85 | void Reset (void); |
86 | /* Generate a CPU RESET */ |
87 | |
88 | void IRQRequest (void); |
89 | /* Generate an IRQ */ |
90 | |
91 | void NMIRequest (void); |
92 | /* Generate an NMI */ |
93 | |
94 | unsigned ExecuteInsn (void); |
95 | /* Execute one CPU instruction. Return the number of clock cycles for the |
96 | ** executed instruction. |
97 | */ |
98 | |
99 | unsigned long GetCycles (void); |
100 | /* Return the total number of clock cycles executed */ |
101 | |
102 | extern int PrintCycles; |
103 | /* flag to print cycles at program termination */ |
104 | |
105 | |
106 | /* End of 6502.h */ |
107 | |
108 | #endif |
109 | |