6cadc2da |
1 | // common code for Memory.c and cd/Memory.c |
2 | // (c) Copyright 2006-2007, Grazvydas "notaz" Ignotas |
fa1e5e29 |
3 | |
eff55556 |
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 | |
fa1e5e29 |
11 | |
12 | #ifndef _ASM_MEMORY_C |
13 | static |
14 | #endif |
15 | u8 z80Read8(u32 a) |
16 | { |
17 | if(Pico.m.z80Run&1) return 0; |
18 | |
19 | a&=0x1fff; |
20 | |
21 | if(!(PicoOpt&4)) { |
22 | // Z80 disabled, do some faking |
23 | static u8 zerosent = 0; |
24 | if(a == Pico.m.z80_lastaddr) { // probably polling something |
25 | u8 d = Pico.m.z80_fakeval; |
26 | if((d & 0xf) == 0xf && !zerosent) { |
27 | d = 0; zerosent = 1; |
28 | } else { |
29 | Pico.m.z80_fakeval++; |
30 | zerosent = 0; |
31 | } |
32 | return d; |
33 | } else { |
34 | Pico.m.z80_fakeval = 0; |
35 | } |
36 | } |
37 | |
38 | Pico.m.z80_lastaddr = (u16) a; |
39 | return Pico.zram[a]; |
40 | } |
41 | |
fa1e5e29 |
42 | #ifndef _ASM_MEMORY_C |
43 | static |
44 | #endif |
e5503e2f |
45 | u32 z80ReadBusReq(void) |
fa1e5e29 |
46 | { |
e5503e2f |
47 | u32 d=Pico.m.z80Run&1; |
f58f05d2 |
48 | if (!d && Pico.m.scanline != -1) { |
e5503e2f |
49 | // needed by buggy Terminator (Sega CD) |
50 | int stop_before = SekCyclesDone() - z80stopCycle; |
69996cb7 |
51 | //elprintf(EL_BUSREQ, "get_zrun: stop before: %i", stop_before); |
52 | // note: if we use 20 or more here, Barkley Shut Up and Jam! will purposedly crash itself. |
5f20bb80 |
53 | // but CD Terminator needs at least 32, so it only works because next frame cycle wrap. |
69996cb7 |
54 | if (stop_before > 0 && stop_before < 20) // Gens uses 16 here |
e5503e2f |
55 | d = 1; // bus not yet available |
56 | } |
57 | // |=0x80 for Shadow of the Beast & Super Offroad |
69996cb7 |
58 | elprintf(EL_BUSREQ, "get_zrun: %02x [%i] @%06x", d|0x80, SekCyclesDone(), SekPc); |
e5503e2f |
59 | return d|0x80; |
60 | } |
fa1e5e29 |
61 | |
e5503e2f |
62 | #ifndef _ASM_MEMORY_C |
63 | static |
64 | #endif |
65 | void z80WriteBusReq(u32 d) |
66 | { |
67 | d&=1; d^=1; |
f58f05d2 |
68 | { |
b542be46 |
69 | if (!d) |
70 | { |
f58f05d2 |
71 | // this is for a nasty situation where Z80 was enabled and disabled in the same 68k timeslice (Golden Axe III) |
72 | if (Pico.m.z80Run) { |
73 | int lineCycles; |
74 | z80stopCycle = SekCyclesDone(); |
9a8ffeee |
75 | if ((Pico.m.z80Run&2) && Pico.m.scanline != -1) |
f58f05d2 |
76 | lineCycles=(488-SekCyclesLeft)&0x1ff; |
77 | else lineCycles=z80stopCycle-z80startCycle; // z80 was started at current line |
9a8ffeee |
78 | if (lineCycles > 0) { // && lineCycles <= 488) { |
69996cb7 |
79 | //dprintf("zrun: %i/%i cycles", lineCycles, (lineCycles>>1)-(lineCycles>>5)); |
f58f05d2 |
80 | lineCycles=(lineCycles>>1)-(lineCycles>>5); |
b542be46 |
81 | z80_run_nr(lineCycles); |
f58f05d2 |
82 | } |
e5503e2f |
83 | } |
f58f05d2 |
84 | } else { |
69996cb7 |
85 | if (!Pico.m.z80Run) |
86 | z80startCycle = SekCyclesDone(); |
87 | else |
88 | d|=Pico.m.z80Run; |
fa1e5e29 |
89 | } |
fa1e5e29 |
90 | } |
69996cb7 |
91 | elprintf(EL_BUSREQ, "set_zrun: %i->%i [%i] @%06x", Pico.m.z80Run, d, SekCyclesDone(), SekPc); |
e5503e2f |
92 | Pico.m.z80Run=(u8)d; |
93 | } |
94 | |
95 | #ifndef _ASM_MEMORY_C |
96 | static |
97 | #endif |
98 | u32 OtherRead16(u32 a, int realsize) |
99 | { |
100 | u32 d=0; |
fa1e5e29 |
101 | |
102 | if ((a&0xffffe0)==0xa10000) { // I/O ports |
103 | a=(a>>1)&0xf; |
104 | switch(a) { |
105 | case 0: d=Pico.m.hardware; break; // Hardware value (Version register) |
e5503e2f |
106 | case 1: d=PadRead(0); break; |
107 | case 2: d=PadRead(1); break; |
fa1e5e29 |
108 | default: d=Pico.ioports[a]; break; // IO ports can be used as RAM |
109 | } |
110 | d|=d<<8; |
111 | goto end; |
112 | } |
113 | |
f58f05d2 |
114 | // rotate fakes next fetched instruction for Time Killers |
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115 | if (a==0xa11100) { // z80 busreq |
e5503e2f |
116 | d=(z80ReadBusReq()<<8)|Pico.m.rotate++; |
fa1e5e29 |
117 | goto end; |
118 | } |
119 | |
e5503e2f |
120 | if ((a&0xff0000)==0xa00000) { |
121 | if ((a&0x4000)==0x0000) { d=z80Read8(a); d|=d<<8; goto end; } // Z80 ram (not byteswaped) |
122 | if ((a&0x6000)==0x4000) { // 0x4000-0x5fff, Fudge if disabled |
123 | if(PicoOpt&1) d=YM2612Read(); |
124 | else d=Pico.m.rotate++&3; |
69996cb7 |
125 | elprintf(EL_YM2612R, "read ym2612: %02x", d); |
e5503e2f |
126 | goto end; |
127 | } |
128 | d=0xffff; |
129 | goto end; |
130 | } |
131 | |
f53f286a |
132 | d = PicoRead16Hook(a, realsize); |
fa1e5e29 |
133 | |
134 | end: |
135 | return d; |
136 | } |
137 | |
e5503e2f |
138 | static void IoWrite8(u32 a, u32 d) |
139 | { |
140 | a=(a>>1)&0xf; |
141 | // 6 button gamepad: if TH went from 0 to 1, gamepad changes state |
142 | if(PicoOpt&0x20) { |
143 | if(a==1) { |
144 | Pico.m.padDelay[0] = 0; |
145 | if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++; |
146 | } |
147 | else if(a==2) { |
148 | Pico.m.padDelay[1] = 0; |
149 | if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++; |
150 | } |
151 | } |
152 | Pico.ioports[a]=(u8)d; // IO ports can be used as RAM |
153 | } |
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154 | |
4ff2d527 |
155 | #ifndef _ASM_CD_MEMORY_C |
156 | static |
157 | #endif |
e5503e2f |
158 | void OtherWrite8(u32 a,u32 d) |
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159 | { |
3ec29f01 |
160 | #if !defined(_ASM_MEMORY_C) || defined(_ASM_MEMORY_C_AMIPS) |
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161 | if ((a&0xe700f9)==0xc00011||(a&0xff7ff9)==0xa07f11) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound |
162 | if ((a&0xff4000)==0xa00000) { if(!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)d; return; } // Z80 ram |
fa283c9a |
163 | if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=YM2612Write(a&3, d)&1; return; } // FM Sound |
e5503e2f |
164 | if ((a&0xffffe0)==0xa10000) { IoWrite8(a, d); return; } // I/O ports |
165 | #endif |
166 | if (a==0xa11100) { z80WriteBusReq(d); return; } |
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167 | if (a==0xa11200) { |
5f20bb80 |
168 | elprintf(EL_BUSREQ, "write z80Reset: %02x", d); |
fa1e5e29 |
169 | if(!(d&1)) z80_reset(); |
170 | return; |
171 | } |
3ec29f01 |
172 | #if !defined(_ASM_MEMORY_C) || defined(_ASM_MEMORY_C_AMIPS) |
fa1e5e29 |
173 | if ((a&0xff7f00)==0xa06000) // Z80 BANK register |
174 | { |
175 | Pico.m.z80_bank68k>>=1; |
176 | Pico.m.z80_bank68k|=(d&1)<<8; |
177 | Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one |
178 | return; |
179 | } |
e5503e2f |
180 | #endif |
fa1e5e29 |
181 | if ((a&0xe700e0)==0xc00000) { |
f58f05d2 |
182 | d&=0xff; |
fa1e5e29 |
183 | PicoVideoWrite(a,(u16)(d|(d<<8))); // Byte access gets mirrored |
184 | return; |
185 | } |
186 | |
f53f286a |
187 | PicoWrite8Hook(a, d, 8); |
fa1e5e29 |
188 | } |
189 | |
190 | |
4ff2d527 |
191 | #ifndef _ASM_CD_MEMORY_C |
192 | static |
193 | #endif |
194 | void OtherWrite16(u32 a,u32 d) |
fa1e5e29 |
195 | { |
e5503e2f |
196 | if (a==0xa11100) { z80WriteBusReq(d>>8); return; } |
ca61ee42 |
197 | if (a==0xa11200) { elprintf(EL_BUSREQ, "write z80reset: %04x", d); if(!(d&0x100)) z80_reset(); return; } |
e5503e2f |
198 | if ((a&0xffffe0)==0xa10000) { IoWrite8(a, d); return; } // I/O ports |
fa1e5e29 |
199 | if ((a&0xff4000)==0xa00000) { if(!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)(d>>8); return; } // Z80 ram (MSB only) |
e5503e2f |
200 | if ((a&0xe700f8)==0xc00010||(a&0xff7ff8)==0xa07f10) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound |
fa283c9a |
201 | if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=YM2612Write(a&3, d)&1; return; } // FM Sound (??) |
e5503e2f |
202 | if ((a&0xff7f00)==0xa06000) // Z80 BANK register |
203 | { |
204 | Pico.m.z80_bank68k>>=1; |
205 | Pico.m.z80_bank68k|=(d&1)<<8; |
206 | Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one |
fa1e5e29 |
207 | return; |
208 | } |
fa1e5e29 |
209 | |
69996cb7 |
210 | #ifndef _CD_MEMORY_C |
7969166e |
211 | if (a >= SRam.start && a <= SRam.end) { |
1dceadae |
212 | elprintf(EL_SRAMIO, "sram w16 [%06x] %04x @ %06x", a, d, SekPc); |
9dc09829 |
213 | if ((Pico.m.sram_reg&0x16)==0x10) { // detected, not EEPROM, write not disabled |
7969166e |
214 | u8 *pm=(u8 *)(SRam.data-SRam.start+a); |
215 | *pm++=d>>8; |
216 | *pm++=d; |
217 | SRam.changed = 1; |
218 | } |
219 | else |
1dceadae |
220 | SRAMWrite(a, d); |
7969166e |
221 | return; |
222 | } |
69996cb7 |
223 | #endif |
f53f286a |
224 | |
f8ef8ff7 |
225 | PicoWrite16Hook(a, d, 16); |
fa1e5e29 |
226 | } |
227 | |