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 | |
602133e1 |
21 | if (!(PicoOpt&POPT_EN_Z80)) |
22 | { |
fa1e5e29 |
23 | // Z80 disabled, do some faking |
24 | static u8 zerosent = 0; |
25 | if(a == Pico.m.z80_lastaddr) { // probably polling something |
26 | u8 d = Pico.m.z80_fakeval; |
27 | if((d & 0xf) == 0xf && !zerosent) { |
28 | d = 0; zerosent = 1; |
29 | } else { |
30 | Pico.m.z80_fakeval++; |
31 | zerosent = 0; |
32 | } |
33 | return d; |
34 | } else { |
35 | Pico.m.z80_fakeval = 0; |
36 | } |
37 | } |
38 | |
39 | Pico.m.z80_lastaddr = (u16) a; |
40 | return Pico.zram[a]; |
41 | } |
42 | |
fa1e5e29 |
43 | #ifndef _ASM_MEMORY_C |
44 | static |
45 | #endif |
e5503e2f |
46 | u32 z80ReadBusReq(void) |
fa1e5e29 |
47 | { |
e5503e2f |
48 | u32 d=Pico.m.z80Run&1; |
f58f05d2 |
49 | if (!d && Pico.m.scanline != -1) { |
e5503e2f |
50 | // needed by buggy Terminator (Sega CD) |
51 | int stop_before = SekCyclesDone() - z80stopCycle; |
69996cb7 |
52 | //elprintf(EL_BUSREQ, "get_zrun: stop before: %i", stop_before); |
53 | // note: if we use 20 or more here, Barkley Shut Up and Jam! will purposedly crash itself. |
5f20bb80 |
54 | // but CD Terminator needs at least 32, so it only works because next frame cycle wrap. |
69996cb7 |
55 | if (stop_before > 0 && stop_before < 20) // Gens uses 16 here |
e5503e2f |
56 | d = 1; // bus not yet available |
57 | } |
58 | // |=0x80 for Shadow of the Beast & Super Offroad |
69996cb7 |
59 | elprintf(EL_BUSREQ, "get_zrun: %02x [%i] @%06x", d|0x80, SekCyclesDone(), SekPc); |
e5503e2f |
60 | return d|0x80; |
61 | } |
fa1e5e29 |
62 | |
e5503e2f |
63 | #ifndef _ASM_MEMORY_C |
64 | static |
65 | #endif |
66 | void z80WriteBusReq(u32 d) |
67 | { |
68 | d&=1; d^=1; |
f58f05d2 |
69 | { |
b542be46 |
70 | if (!d) |
71 | { |
f58f05d2 |
72 | // this is for a nasty situation where Z80 was enabled and disabled in the same 68k timeslice (Golden Axe III) |
bd613473 |
73 | if ((PicoOpt&POPT_EN_Z80) && Pico.m.z80Run) |
74 | { |
f58f05d2 |
75 | int lineCycles; |
76 | z80stopCycle = SekCyclesDone(); |
9a8ffeee |
77 | if ((Pico.m.z80Run&2) && Pico.m.scanline != -1) |
f58f05d2 |
78 | lineCycles=(488-SekCyclesLeft)&0x1ff; |
79 | else lineCycles=z80stopCycle-z80startCycle; // z80 was started at current line |
9a8ffeee |
80 | if (lineCycles > 0) { // && lineCycles <= 488) { |
69996cb7 |
81 | //dprintf("zrun: %i/%i cycles", lineCycles, (lineCycles>>1)-(lineCycles>>5)); |
f58f05d2 |
82 | lineCycles=(lineCycles>>1)-(lineCycles>>5); |
b542be46 |
83 | z80_run_nr(lineCycles); |
f58f05d2 |
84 | } |
e5503e2f |
85 | } |
f58f05d2 |
86 | } else { |
69996cb7 |
87 | if (!Pico.m.z80Run) |
88 | z80startCycle = SekCyclesDone(); |
89 | else |
90 | d|=Pico.m.z80Run; |
fa1e5e29 |
91 | } |
fa1e5e29 |
92 | } |
69996cb7 |
93 | elprintf(EL_BUSREQ, "set_zrun: %i->%i [%i] @%06x", Pico.m.z80Run, d, SekCyclesDone(), SekPc); |
e5503e2f |
94 | Pico.m.z80Run=(u8)d; |
95 | } |
96 | |
97 | #ifndef _ASM_MEMORY_C |
98 | static |
99 | #endif |
100 | u32 OtherRead16(u32 a, int realsize) |
101 | { |
102 | u32 d=0; |
fa1e5e29 |
103 | |
104 | if ((a&0xffffe0)==0xa10000) { // I/O ports |
105 | a=(a>>1)&0xf; |
106 | switch(a) { |
107 | case 0: d=Pico.m.hardware; break; // Hardware value (Version register) |
e5503e2f |
108 | case 1: d=PadRead(0); break; |
109 | case 2: d=PadRead(1); break; |
fa1e5e29 |
110 | default: d=Pico.ioports[a]; break; // IO ports can be used as RAM |
111 | } |
112 | d|=d<<8; |
113 | goto end; |
114 | } |
115 | |
f58f05d2 |
116 | // rotate fakes next fetched instruction for Time Killers |
fa1e5e29 |
117 | if (a==0xa11100) { // z80 busreq |
e5503e2f |
118 | d=(z80ReadBusReq()<<8)|Pico.m.rotate++; |
fa1e5e29 |
119 | goto end; |
120 | } |
121 | |
bd613473 |
122 | if ((a&0xff0000)==0xa00000) |
123 | { |
124 | if (Pico.m.z80Run&1) |
583ab72c |
125 | elprintf(EL_ANOMALY, "68k z80 read with no bus! [%06x] @ %06x", a, SekPc); |
e5503e2f |
126 | if ((a&0x4000)==0x0000) { d=z80Read8(a); d|=d<<8; goto end; } // Z80 ram (not byteswaped) |
127 | if ((a&0x6000)==0x4000) { // 0x4000-0x5fff, Fudge if disabled |
602133e1 |
128 | if(PicoOpt&POPT_EN_FM) d=YM2612Read(); |
e5503e2f |
129 | else d=Pico.m.rotate++&3; |
69996cb7 |
130 | elprintf(EL_YM2612R, "read ym2612: %02x", d); |
e5503e2f |
131 | goto end; |
132 | } |
bd613473 |
133 | elprintf(EL_ANOMALY, "68k bad read [%06x]", a); |
e5503e2f |
134 | d=0xffff; |
135 | goto end; |
136 | } |
137 | |
f53f286a |
138 | d = PicoRead16Hook(a, realsize); |
fa1e5e29 |
139 | |
140 | end: |
141 | return d; |
142 | } |
143 | |
e5503e2f |
144 | static void IoWrite8(u32 a, u32 d) |
145 | { |
146 | a=(a>>1)&0xf; |
147 | // 6 button gamepad: if TH went from 0 to 1, gamepad changes state |
583ab72c |
148 | if (PicoOpt&POPT_6BTN_PAD) |
602133e1 |
149 | { |
150 | if (a==1) { |
e5503e2f |
151 | Pico.m.padDelay[0] = 0; |
152 | if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++; |
153 | } |
602133e1 |
154 | else if (a==2) { |
e5503e2f |
155 | Pico.m.padDelay[1] = 0; |
156 | if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++; |
157 | } |
158 | } |
159 | Pico.ioports[a]=(u8)d; // IO ports can be used as RAM |
160 | } |
fa1e5e29 |
161 | |
4ff2d527 |
162 | #ifndef _ASM_CD_MEMORY_C |
163 | static |
164 | #endif |
e5503e2f |
165 | void OtherWrite8(u32 a,u32 d) |
fa1e5e29 |
166 | { |
3ec29f01 |
167 | #if !defined(_ASM_MEMORY_C) || defined(_ASM_MEMORY_C_AMIPS) |
fa1e5e29 |
168 | if ((a&0xe700f9)==0xc00011||(a&0xff7ff9)==0xa07f11) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound |
bd613473 |
169 | if ((a&0xff4000)==0xa00000) { // z80 RAM |
170 | if (!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)d; |
583ab72c |
171 | else { |
172 | elprintf(EL_ANOMALY, "68k z80 write with no bus! [%06x] %02x @ %06x", a, d, SekPc); |
173 | SekCyclesBurn(4); // hack? |
174 | } |
bd613473 |
175 | return; |
176 | } |
fa283c9a |
177 | if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=YM2612Write(a&3, d)&1; return; } // FM Sound |
e5503e2f |
178 | if ((a&0xffffe0)==0xa10000) { IoWrite8(a, d); return; } // I/O ports |
179 | #endif |
180 | if (a==0xa11100) { z80WriteBusReq(d); return; } |
fa1e5e29 |
181 | if (a==0xa11200) { |
5f20bb80 |
182 | elprintf(EL_BUSREQ, "write z80Reset: %02x", d); |
bd613473 |
183 | if (!(d&0x1)) { Pico.m.z80_reset = 1; Pico.m.z80Run = 0; YM2612ResetChip(); } |
184 | else if (Pico.m.z80_reset) { |
185 | Pico.m.z80_reset = 0; |
186 | YM2612ResetChip(); |
187 | z80_reset(); |
188 | } |
fa1e5e29 |
189 | return; |
190 | } |
3ec29f01 |
191 | #if !defined(_ASM_MEMORY_C) || defined(_ASM_MEMORY_C_AMIPS) |
fa1e5e29 |
192 | if ((a&0xff7f00)==0xa06000) // Z80 BANK register |
193 | { |
194 | Pico.m.z80_bank68k>>=1; |
195 | Pico.m.z80_bank68k|=(d&1)<<8; |
196 | Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one |
bd613473 |
197 | elprintf(EL_Z80BNK, "z80 bank=%06x", Pico.m.z80_bank68k<<15); |
fa1e5e29 |
198 | return; |
199 | } |
e5503e2f |
200 | #endif |
fa1e5e29 |
201 | if ((a&0xe700e0)==0xc00000) { |
f58f05d2 |
202 | d&=0xff; |
fa1e5e29 |
203 | PicoVideoWrite(a,(u16)(d|(d<<8))); // Byte access gets mirrored |
204 | return; |
205 | } |
206 | |
f53f286a |
207 | PicoWrite8Hook(a, d, 8); |
fa1e5e29 |
208 | } |
209 | |
210 | |
4ff2d527 |
211 | #ifndef _ASM_CD_MEMORY_C |
212 | static |
213 | #endif |
214 | void OtherWrite16(u32 a,u32 d) |
fa1e5e29 |
215 | { |
e5503e2f |
216 | if (a==0xa11100) { z80WriteBusReq(d>>8); return; } |
e5503e2f |
217 | if ((a&0xffffe0)==0xa10000) { IoWrite8(a, d); return; } // I/O ports |
e5503e2f |
218 | if ((a&0xe700f8)==0xc00010||(a&0xff7ff8)==0xa07f10) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound |
bd613473 |
219 | if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=YM2612Write(a&3, d)&1; return; } // FM Sound (??) |
220 | if ((a&0xff4000)==0xa00000) { // Z80 ram (MSB only) |
221 | if (!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)(d>>8); |
583ab72c |
222 | else elprintf(EL_ANOMALY, "68k z80 write with no bus! [%06x] %02x @ %06x", a, d, SekPc); |
bd613473 |
223 | return; |
224 | } |
225 | if (a==0xa11200) { |
226 | elprintf(EL_BUSREQ, "write z80reset: %04x", d); |
227 | if (!(d&0x100)) { Pico.m.z80_reset = 1; Pico.m.z80Run = 0; YM2612ResetChip(); } |
228 | else if (Pico.m.z80_reset) { |
229 | Pico.m.z80_reset = 0; |
230 | YM2612ResetChip(); |
231 | z80_reset(); |
232 | } |
233 | return; |
234 | } |
e5503e2f |
235 | if ((a&0xff7f00)==0xa06000) // Z80 BANK register |
236 | { |
237 | Pico.m.z80_bank68k>>=1; |
238 | Pico.m.z80_bank68k|=(d&1)<<8; |
239 | Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one |
bd613473 |
240 | elprintf(EL_Z80BNK, "z80 bank=%06x", Pico.m.z80_bank68k<<15); |
fa1e5e29 |
241 | return; |
242 | } |
fa1e5e29 |
243 | |
69996cb7 |
244 | #ifndef _CD_MEMORY_C |
7969166e |
245 | if (a >= SRam.start && a <= SRam.end) { |
1dceadae |
246 | elprintf(EL_SRAMIO, "sram w16 [%06x] %04x @ %06x", a, d, SekPc); |
9dc09829 |
247 | if ((Pico.m.sram_reg&0x16)==0x10) { // detected, not EEPROM, write not disabled |
7969166e |
248 | u8 *pm=(u8 *)(SRam.data-SRam.start+a); |
249 | *pm++=d>>8; |
250 | *pm++=d; |
251 | SRam.changed = 1; |
252 | } |
253 | else |
1dceadae |
254 | SRAMWrite(a, d); |
7969166e |
255 | return; |
256 | } |
69996cb7 |
257 | #endif |
f53f286a |
258 | |
f8ef8ff7 |
259 | PicoWrite16Hook(a, d, 16); |
fa1e5e29 |
260 | } |
261 | |