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 */
48typedef enum CPUType {
49 CPU_6502,
50 CPU_65C02
51} CPUType;
52
53/* Current CPU */
54extern CPUType CPU;
55
56/* 6502 CPU registers */
57typedef struct CPURegs CPURegs;
58struct 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
85void Reset (void);
86/* Generate a CPU RESET */
87
88void IRQRequest (void);
89/* Generate an IRQ */
90
91void NMIRequest (void);
92/* Generate an NMI */
93
94unsigned ExecuteInsn (void);
95/* Execute one CPU instruction. Return the number of clock cycles for the
96** executed instruction.
97*/
98
99unsigned long GetCycles (void);
100/* Return the total number of clock cycles executed */
101
102extern int PrintCycles;
103/* flag to print cycles at program termination */
104
105
106/* End of 6502.h */
107
108#endif
109