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root/cebix/Frodo4/Src/CPUC64.h
Revision: 1.4
Committed: 2004-01-12T15:13:20Z (19 years, 1 month ago) by cebix
Content type: text/plain
Branch: MAIN
Changes since 1.3: +1 -1 lines
Log Message:
Happy New Year!

File Contents

# Content
1 /*
2 * CPUC64.h - 6510 (C64) emulation (line based)
3 *
4 * Frodo (C) 1994-1997,2002-2004 Christian Bauer
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU 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
21 #ifndef _CPU_C64_H
22 #define _CPU_C64_H
23
24 #include "C64.h"
25
26
27 // Set this to 1 if the 6502 PC should be represented by a real pointer
28 #ifndef FRODO_SC
29 #ifndef PC_IS_POINTER
30 #define PC_IS_POINTER 1
31 #endif
32 #endif
33
34 // Set this to 1 for more precise CPU cycle calculation
35 #ifndef PRECISE_CPU_CYCLES
36 #define PRECISE_CPU_CYCLES 0
37 #endif
38
39 // Set this to 1 for instruction-aligned CIA emulation
40 #ifndef PRECISE_CIA_CYCLES
41 #define PRECISE_CIA_CYCLES 0
42 #endif
43
44
45 // Interrupt types
46 enum {
47 INT_VICIRQ,
48 INT_CIAIRQ,
49 INT_NMI
50 // INT_RESET (private)
51 };
52
53
54 class MOS6569;
55 class MOS6581;
56 class MOS6526_1;
57 class MOS6526_2;
58 class REU;
59 class IEC;
60 struct MOS6510State;
61
62
63 // 6510 emulation (C64)
64 class MOS6510 {
65 public:
66 MOS6510(C64 *c64, uint8 *Ram, uint8 *Basic, uint8 *Kernal, uint8 *Char, uint8 *Color);
67
68 #ifdef FRODO_SC
69 void EmulateCycle(void); // Emulate one clock cycle
70 #else
71 int EmulateLine(int cycles_left); // Emulate until cycles_left underflows
72 #endif
73 void Reset(void);
74 void AsyncReset(void); // Reset the CPU asynchronously
75 void AsyncNMI(void); // Raise NMI asynchronously (NMI pulse)
76 void GetState(MOS6510State *s);
77 void SetState(MOS6510State *s);
78 uint8 ExtReadByte(uint16 adr);
79 void ExtWriteByte(uint16 adr, uint8 byte);
80 uint8 REUReadByte(uint16 adr);
81 void REUWriteByte(uint16 adr, uint8 byte);
82
83 void TriggerVICIRQ(void);
84 void ClearVICIRQ(void);
85 void TriggerCIAIRQ(void);
86 void ClearCIAIRQ(void);
87 void TriggerNMI(void);
88 void ClearNMI(void);
89
90 int ExtConfig; // Memory configuration for ExtRead/WriteByte (0..7)
91
92 MOS6569 *TheVIC; // Pointer to VIC
93 MOS6581 *TheSID; // Pointer to SID
94 MOS6526_1 *TheCIA1; // Pointer to CIA 1
95 MOS6526_2 *TheCIA2; // Pointer to CIA 2
96 REU *TheREU; // Pointer to REU
97 IEC *TheIEC; // Pointer to drive array
98
99 #ifdef FRODO_SC
100 bool BALow; // BA line for Frodo SC
101 #endif
102
103 private:
104 uint8 read_byte(uint16 adr);
105 uint8 read_byte_io(uint16 adr);
106 uint16 read_word(uint16 adr);
107 void write_byte(uint16 adr, uint8 byte);
108 void write_byte_io(uint16 adr, uint8 byte);
109
110 uint8 read_zp(uint16 adr);
111 uint16 read_zp_word(uint16 adr);
112 void write_zp(uint16 adr, uint8 byte);
113
114 void new_config(void);
115 void illegal_op(uint8 op, uint16 at);
116 void illegal_jump(uint16 at, uint16 to);
117
118 void do_adc(uint8 byte);
119 void do_sbc(uint8 byte);
120
121 uint8 read_emulator_id(uint16 adr);
122
123 C64 *the_c64; // Pointer to C64 object
124
125 uint8 *ram; // Pointer to main RAM
126 uint8 *basic_rom, *kernal_rom, *char_rom, *color_ram; // Pointers to ROMs and color RAM
127
128 union { // Pending interrupts
129 uint8 intr[4]; // Index: See definitions above
130 unsigned long intr_any;
131 } interrupt;
132 bool nmi_state; // State of NMI line
133
134 uint8 n_flag, z_flag;
135 bool v_flag, d_flag, i_flag, c_flag;
136 uint8 a, x, y, sp;
137
138 #if PC_IS_POINTER
139 uint8 *pc, *pc_base;
140 #else
141 uint16 pc;
142 #endif
143
144 #ifdef FRODO_SC
145 uint32 first_irq_cycle, first_nmi_cycle;
146
147 uint8 state, op; // Current state and opcode
148 uint16 ar, ar2; // Address registers
149 uint8 rdbuf; // Data buffer for RMW instructions
150 uint8 ddr, pr; // Processor port
151 #else
152 int borrowed_cycles; // Borrowed cycles from next line
153 #endif
154
155 bool basic_in, kernal_in, char_in, io_in;
156 uint8 dfff_byte;
157 };
158
159 // 6510 state
160 struct MOS6510State {
161 uint8 a, x, y;
162 uint8 p; // Processor flags
163 uint8 ddr, pr; // Port
164 uint16 pc, sp;
165 uint8 intr[4]; // Interrupt state
166 bool nmi_state;
167 uint8 dfff_byte;
168 bool instruction_complete;
169 };
170
171
172 // Interrupt functions
173 #ifdef FRODO_SC
174 inline void MOS6510::TriggerVICIRQ(void)
175 {
176 if (!(interrupt.intr[INT_VICIRQ] || interrupt.intr[INT_CIAIRQ]))
177 first_irq_cycle = the_c64->CycleCounter;
178 interrupt.intr[INT_VICIRQ] = true;
179 }
180
181 inline void MOS6510::TriggerCIAIRQ(void)
182 {
183 if (!(interrupt.intr[INT_VICIRQ] || interrupt.intr[INT_CIAIRQ]))
184 first_irq_cycle = the_c64->CycleCounter;
185 interrupt.intr[INT_CIAIRQ] = true;
186 }
187
188 inline void MOS6510::TriggerNMI(void)
189 {
190 if (!nmi_state) {
191 nmi_state = true;
192 interrupt.intr[INT_NMI] = true;
193 first_nmi_cycle = the_c64->CycleCounter;
194 }
195 }
196 #else
197 inline void MOS6510::TriggerVICIRQ(void)
198 {
199 interrupt.intr[INT_VICIRQ] = true;
200 }
201
202 inline void MOS6510::TriggerCIAIRQ(void)
203 {
204 interrupt.intr[INT_CIAIRQ] = true;
205 }
206
207 inline void MOS6510::TriggerNMI(void)
208 {
209 if (!nmi_state) {
210 nmi_state = true;
211 interrupt.intr[INT_NMI] = true;
212 }
213 }
214 #endif
215 inline void MOS6510::ClearVICIRQ(void)
216 {
217 interrupt.intr[INT_VICIRQ] = false;
218 }
219
220 inline void MOS6510::ClearCIAIRQ(void)
221 {
222 interrupt.intr[INT_CIAIRQ] = false;
223 }
224
225 inline void MOS6510::ClearNMI(void)
226 {
227 nmi_state = false;
228 }
229
230 #endif