1 // common code for Memory.c and cd/Memory.c
2 // (c) Copyright 2006-2007, Grazvydas "notaz" Ignotas
5 typedef unsigned char u8;
6 typedef unsigned short u16;
7 typedef unsigned int u32;
17 if(Pico.m.z80Run&1) return 0;
21 if (!(PicoOpt&POPT_EN_Z80))
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) {
35 Pico.m.z80_fakeval = 0;
39 Pico.m.z80_lastaddr = (u16) a;
46 u32 z80ReadBusReq(void)
48 u32 d=Pico.m.z80Run&1;
49 if (!d && Pico.m.scanline != -1) {
50 // needed by buggy Terminator (Sega CD)
51 int stop_before = SekCyclesDone() - z80stopCycle;
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.
54 // but CD Terminator needs at least 32, so it only works because next frame cycle wrap.
55 if (stop_before > 0 && stop_before < 20) // Gens uses 16 here
56 d = 1; // bus not yet available
58 // |=0x80 for Shadow of the Beast & Super Offroad
59 elprintf(EL_BUSREQ, "get_zrun: %02x [%i] @%06x", d|0x80, SekCyclesDone(), SekPc);
66 void z80WriteBusReq(u32 d)
72 // this is for a nasty situation where Z80 was enabled and disabled in the same 68k timeslice (Golden Axe III)
73 if ((PicoOpt&POPT_EN_Z80) && Pico.m.z80Run)
76 z80stopCycle = SekCyclesDone();
77 if ((Pico.m.z80Run&2) && Pico.m.scanline != -1)
78 lineCycles=(488-SekCyclesLeft)&0x1ff;
79 else lineCycles=z80stopCycle-z80startCycle; // z80 was started at current line
80 if (lineCycles > 0) { // && lineCycles <= 488) {
81 //dprintf("zrun: %i/%i cycles", lineCycles, (lineCycles>>1)-(lineCycles>>5));
82 lineCycles=(lineCycles>>1)-(lineCycles>>5);
83 z80_run_nr(lineCycles);
88 z80startCycle = SekCyclesDone();
93 elprintf(EL_BUSREQ, "set_zrun: %i->%i [%i] @%06x", Pico.m.z80Run, d, SekCyclesDone(), SekPc);
100 u32 OtherRead16(u32 a, int realsize)
104 if ((a&0xffffe0)==0xa10000) { // I/O ports
107 case 0: d=Pico.m.hardware; break; // Hardware value (Version register)
108 case 1: d=PadRead(0); break;
109 case 2: d=PadRead(1); break;
110 default: d=Pico.ioports[a]; break; // IO ports can be used as RAM
116 // rotate fakes next fetched instruction for Time Killers
117 if (a==0xa11100) { // z80 busreq
118 d=(z80ReadBusReq()<<8)|Pico.m.rotate++;
122 if ((a&0xff0000)==0xa00000)
125 elprintf(EL_ANOMALY, "68k z80 read with no bus! [%06x] @ %06x", a, SekPc);
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
128 if(PicoOpt&POPT_EN_FM) d=YM2612Read();
129 else d=Pico.m.rotate++&3;
130 elprintf(EL_YM2612R, "read ym2612: %02x", d);
133 elprintf(EL_ANOMALY, "68k bad read [%06x]", a);
138 d = PicoRead16Hook(a, realsize);
144 static void IoWrite8(u32 a, u32 d)
147 // 6 button gamepad: if TH went from 0 to 1, gamepad changes state
148 if (PicoOpt&POPT_6BTN_PAD)
151 Pico.m.padDelay[0] = 0;
152 if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++;
155 Pico.m.padDelay[1] = 0;
156 if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++;
159 Pico.ioports[a]=(u8)d; // IO ports can be used as RAM
162 #ifndef _ASM_CD_MEMORY_C
165 void OtherWrite8(u32 a,u32 d)
167 #if !defined(_ASM_MEMORY_C) || defined(_ASM_MEMORY_C_AMIPS)
168 if ((a&0xe700f9)==0xc00011||(a&0xff7ff9)==0xa07f11) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound
169 if ((a&0xff4000)==0xa00000) { // z80 RAM
170 if (!(Pico.m.z80Run&1)) Pico.zram[a&0x1fff]=(u8)d;
172 elprintf(EL_ANOMALY, "68k z80 write with no bus! [%06x] %02x @ %06x", a, d, SekPc);
173 SekCyclesBurn(4); // hack?
177 if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=YM2612Write(a&3, d)&1; return; } // FM Sound
178 if ((a&0xffffe0)==0xa10000) { IoWrite8(a, d); return; } // I/O ports
180 if (a==0xa11100) { z80WriteBusReq(d); return; }
182 elprintf(EL_BUSREQ, "write z80Reset: %02x", d);
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;
191 #if !defined(_ASM_MEMORY_C) || defined(_ASM_MEMORY_C_AMIPS)
192 if ((a&0xff7f00)==0xa06000) // Z80 BANK register
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
197 elprintf(EL_Z80BNK, "z80 bank=%06x", Pico.m.z80_bank68k<<15);
201 if ((a&0xe700e0)==0xc00000) {
203 PicoVideoWrite(a,(u16)(d|(d<<8))); // Byte access gets mirrored
207 PicoWrite8Hook(a, d, 8);
211 #ifndef _ASM_CD_MEMORY_C
214 void OtherWrite16(u32 a,u32 d)
216 if (a==0xa11100) { z80WriteBusReq(d>>8); return; }
217 if ((a&0xffffe0)==0xa10000) { IoWrite8(a, d); return; } // I/O ports
218 if ((a&0xe700f8)==0xc00010||(a&0xff7ff8)==0xa07f10) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound
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);
222 else elprintf(EL_ANOMALY, "68k z80 write with no bus! [%06x] %02x @ %06x", a, d, SekPc);
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;
235 if ((a&0xff7f00)==0xa06000) // Z80 BANK register
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
240 elprintf(EL_Z80BNK, "z80 bank=%06x", Pico.m.z80_bank68k<<15);
245 if (a >= SRam.start && a <= SRam.end) {
246 elprintf(EL_SRAMIO, "sram w16 [%06x] %04x @ %06x", a, d, SekPc);
247 if ((Pico.m.sram_reg&0x16)==0x10) { // detected, not EEPROM, write not disabled
248 u8 *pm=(u8 *)(SRam.data-SRam.start+a);
259 PicoWrite16Hook(a, d, 16);