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1 | // common code for Memory.c and cd/Memory.c |
2 | // (c) Copyright 2006-2007, Grazvydas "notaz" Ignotas |
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3 | |
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4 | #ifndef UTYPES_DEFINED |
5 | typedef unsigned char u8; |
6 | typedef unsigned short u16; |
7 | typedef unsigned int u32; |
8 | #define UTYPES_DEFINED |
9 | #endif |
10 | |
11 | #ifdef _ASM_MEMORY_C |
12 | u32 OtherRead16End(u32 a, int realsize); |
13 | #endif |
14 | #ifdef _ASM_CD_MEMORY_C |
15 | static void OtherWrite8End(u32 a,u32 d,int realsize); |
16 | #endif |
17 | |
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18 | static int PadRead(int i) |
19 | { |
20 | int pad=0,value=0,TH; |
21 | pad=~PicoPad[i]; // Get inverse of pad MXYZ SACB RLDU |
22 | TH=Pico.ioports[i+1]&0x40; |
23 | |
24 | if(PicoOpt & 0x20) { // 6 button gamepad enabled |
25 | int phase = Pico.m.padTHPhase[i]; |
26 | |
27 | if(phase == 2 && !TH) { |
28 | value=(pad&0xc0)>>2; // ?0SA 0000 |
29 | goto end; |
30 | } else if(phase == 3 && TH) { |
31 | value=(pad&0x30)|((pad>>8)&0xf); // ?1CB MXYZ |
32 | goto end; |
33 | } else if(phase == 3 && !TH) { |
34 | value=((pad&0xc0)>>2)|0x0f; // ?0SA 1111 |
35 | goto end; |
36 | } |
37 | } |
38 | |
39 | if(TH) value=(pad&0x3f); // ?1CB RLDU |
40 | else value=((pad&0xc0)>>2)|(pad&3); // ?0SA 00DU |
41 | |
42 | end: |
43 | |
44 | // orr the bits, which are set as output |
45 | value |= Pico.ioports[i+1]&Pico.ioports[i+4]; |
46 | |
47 | return value; // will mirror later |
48 | } |
49 | |
50 | |
51 | #ifndef _ASM_MEMORY_C |
52 | static |
53 | #endif |
54 | u8 z80Read8(u32 a) |
55 | { |
56 | if(Pico.m.z80Run&1) return 0; |
57 | |
58 | a&=0x1fff; |
59 | |
60 | if(!(PicoOpt&4)) { |
61 | // Z80 disabled, do some faking |
62 | static u8 zerosent = 0; |
63 | if(a == Pico.m.z80_lastaddr) { // probably polling something |
64 | u8 d = Pico.m.z80_fakeval; |
65 | if((d & 0xf) == 0xf && !zerosent) { |
66 | d = 0; zerosent = 1; |
67 | } else { |
68 | Pico.m.z80_fakeval++; |
69 | zerosent = 0; |
70 | } |
71 | return d; |
72 | } else { |
73 | Pico.m.z80_fakeval = 0; |
74 | } |
75 | } |
76 | |
77 | Pico.m.z80_lastaddr = (u16) a; |
78 | return Pico.zram[a]; |
79 | } |
80 | |
81 | |
82 | #ifndef _ASM_MEMORY_C |
83 | static |
84 | #endif |
85 | u32 OtherRead16(u32 a, int realsize) |
86 | { |
87 | u32 d=0; |
88 | |
89 | if ((a&0xff0000)==0xa00000) { |
90 | if ((a&0x4000)==0x0000) { d=z80Read8(a); d|=d<<8; goto end; } // Z80 ram (not byteswaped) |
91 | if ((a&0x6000)==0x4000) { // 0x4000-0x5fff, Fudge if disabled |
92 | if(PicoOpt&1) d=YM2612Read(); |
93 | else d=Pico.m.rotate++&3; |
94 | dprintf("read ym2612: %04x", d); |
95 | goto end; |
96 | } |
97 | d=0xffff; |
98 | goto end; |
99 | } |
100 | |
101 | if ((a&0xffffe0)==0xa10000) { // I/O ports |
102 | a=(a>>1)&0xf; |
103 | switch(a) { |
104 | case 0: d=Pico.m.hardware; break; // Hardware value (Version register) |
105 | case 1: d=PadRead(0); d|=Pico.ioports[1]&0x80; break; |
106 | case 2: d=PadRead(1); d|=Pico.ioports[2]&0x80; break; |
107 | default: d=Pico.ioports[a]; break; // IO ports can be used as RAM |
108 | } |
109 | d|=d<<8; |
110 | goto end; |
111 | } |
112 | |
113 | // |=0x80 for Shadow of the Beast & Super Offroad; rotate fakes next fetched instruction for Time Killers |
114 | if (a==0xa11100) { // z80 busreq |
115 | d=Pico.m.z80Run&1; |
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116 | #if 1 |
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117 | if (!d) { |
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118 | // needed by buggy Terminator (Sega CD) |
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119 | int stop_before = SekCyclesDone() - z80stopCycle; |
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120 | dprintf("stop before: %i", stop_before); |
121 | if (stop_before > 0 && stop_before <= 32) // Gens uses 16 here |
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122 | d = 1; // bus not yet available |
123 | } |
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124 | #endif |
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125 | d=(d<<8)|0x8000|Pico.m.rotate++; |
126 | dprintf("get_zrun: %04x [%i|%i] @%06x", d, Pico.m.scanline, SekCyclesDone(), SekPc); |
127 | goto end; |
128 | } |
129 | |
130 | #ifndef _ASM_MEMORY_C |
131 | if ((a&0xe700e0)==0xc00000) { d=PicoVideoRead(a); goto end; } |
132 | #endif |
133 | |
134 | d = OtherRead16End(a, realsize); |
135 | |
136 | end: |
137 | return d; |
138 | } |
139 | |
140 | |
141 | //extern UINT32 mz80GetRegisterValue(void *, UINT32); |
142 | |
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143 | #ifndef _ASM_CD_MEMORY_C |
144 | static |
145 | #endif |
146 | void OtherWrite8(u32 a,u32 d,int realsize) |
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147 | { |
148 | if ((a&0xe700f9)==0xc00011||(a&0xff7ff9)==0xa07f11) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound |
149 | if ((a&0xff4000)==0xa00000) { if(!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)d; return; } // Z80 ram |
150 | if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=YM2612Write(a&3, d); return; } // FM Sound |
151 | if ((a&0xffffe0)==0xa10000) { // I/O ports |
152 | a=(a>>1)&0xf; |
153 | // 6 button gamepad: if TH went from 0 to 1, gamepad changes state |
154 | if(PicoOpt&0x20) { |
155 | if(a==1) { |
156 | Pico.m.padDelay[0] = 0; |
157 | if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++; |
158 | } |
159 | else if(a==2) { |
160 | Pico.m.padDelay[1] = 0; |
161 | if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++; |
162 | } |
163 | } |
164 | Pico.ioports[a]=(u8)d; // IO ports can be used as RAM |
165 | return; |
166 | } |
167 | if (a==0xa11100) { |
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168 | //int lineCycles=(488-SekCyclesLeft)&0x1ff; |
169 | d&=1; d^=1; |
170 | if(!d) { |
171 | // this is for a nasty situation where Z80 was enabled and disabled in the same 68k timeslice (Golden Axe III) |
172 | if (Pico.m.z80Run) { |
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173 | int lineCycles; |
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174 | z80stopCycle = SekCyclesDone(); |
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175 | if (Pico.m.z80Run&2) |
176 | lineCycles=(488-SekCyclesLeft)&0x1ff; |
177 | else lineCycles=z80stopCycle-z80startCycle; // z80 was started at current line |
178 | if (lineCycles > 0 && lineCycles <= 488) { |
179 | dprintf("zrun: %i/%i cycles", lineCycles, (lineCycles>>1)-(lineCycles>>5)); |
180 | lineCycles=(lineCycles>>1)-(lineCycles>>5); |
181 | z80_run(lineCycles); |
182 | } |
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183 | } |
184 | } else { |
185 | z80startCycle = SekCyclesDone(); |
186 | //if(Pico.m.scanline != -1) |
187 | } |
188 | dprintf("set_zrun: %02x [%i|%i] @%06x", d, Pico.m.scanline, SekCyclesDone(), /*mz80GetRegisterValue(NULL, 0),*/ SekPc); |
189 | Pico.m.z80Run=(u8)d; return; |
190 | } |
191 | if (a==0xa11200) { |
192 | dprintf("write z80Reset: %02x", d); |
193 | if(!(d&1)) z80_reset(); |
194 | return; |
195 | } |
196 | |
197 | if ((a&0xff7f00)==0xa06000) // Z80 BANK register |
198 | { |
199 | Pico.m.z80_bank68k>>=1; |
200 | Pico.m.z80_bank68k|=(d&1)<<8; |
201 | Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one |
202 | return; |
203 | } |
204 | |
205 | if ((a&0xe700e0)==0xc00000) { |
206 | PicoVideoWrite(a,(u16)(d|(d<<8))); // Byte access gets mirrored |
207 | return; |
208 | } |
209 | |
210 | OtherWrite8End(a, d, realsize); |
211 | } |
212 | |
213 | |
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214 | #ifndef _ASM_CD_MEMORY_C |
215 | static |
216 | #endif |
217 | void OtherWrite16(u32 a,u32 d) |
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218 | { |
219 | if ((a&0xe700e0)==0xc00000) { PicoVideoWrite(a,(u16)d); return; } |
220 | if ((a&0xff4000)==0xa00000) { if(!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)(d>>8); return; } // Z80 ram (MSB only) |
221 | |
222 | if ((a&0xffffe0)==0xa10000) { // I/O ports |
223 | a=(a>>1)&0xf; |
224 | // 6 button gamepad: if TH went from 0 to 1, gamepad changes state |
225 | if(PicoOpt&0x20) { |
226 | if(a==1) { |
227 | Pico.m.padDelay[0] = 0; |
228 | if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++; |
229 | } |
230 | else if(a==2) { |
231 | Pico.m.padDelay[1] = 0; |
232 | if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++; |
233 | } |
234 | } |
235 | Pico.ioports[a]=(u8)d; // IO ports can be used as RAM |
236 | return; |
237 | } |
238 | if (a==0xa11100) { OtherWrite8(a, d>>8, 16); return; } |
239 | if (a==0xa11200) { dprintf("write z80reset: %04x", d); if(!(d&0x100)) z80_reset(); return; } |
240 | |
241 | OtherWrite8(a, d>>8, 16); |
242 | OtherWrite8(a+1,d&0xff, 16); |
243 | } |
244 | |
245 | |