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;
12 u32 OtherRead16End(u32 a, int realsize);
14 #ifdef _ASM_CD_MEMORY_C
15 static void OtherWrite8End(u32 a,u32 d,int realsize);
18 static int PadRead(int i)
21 pad=~PicoPad[i]; // Get inverse of pad MXYZ SACB RLDU
22 TH=Pico.ioports[i+1]&0x40;
24 if(PicoOpt & 0x20) { // 6 button gamepad enabled
25 int phase = Pico.m.padTHPhase[i];
27 if(phase == 2 && !TH) {
28 value=(pad&0xc0)>>2; // ?0SA 0000
30 } else if(phase == 3 && TH) {
31 value=(pad&0x30)|((pad>>8)&0xf); // ?1CB MXYZ
33 } else if(phase == 3 && !TH) {
34 value=((pad&0xc0)>>2)|0x0f; // ?0SA 1111
39 if(TH) value=(pad&0x3f); // ?1CB RLDU
40 else value=((pad&0xc0)>>2)|(pad&3); // ?0SA 00DU
44 // orr the bits, which are set as output
45 value |= Pico.ioports[i+1]&Pico.ioports[i+4];
47 return value; // will mirror later
56 if(Pico.m.z80Run&1) return 0;
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) {
73 Pico.m.z80_fakeval = 0;
77 Pico.m.z80_lastaddr = (u16) a;
85 u32 OtherRead16(u32 a, int realsize)
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);
101 if ((a&0xffffe0)==0xa10000) { // I/O ports
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
113 // |=0x80 for Shadow of the Beast & Super Offroad; rotate fakes next fetched instruction for Time Killers
114 if (a==0xa11100) { // z80 busreq
118 // needed by buggy Terminator (Sega CD)
119 int stop_before = SekCyclesDone() - z80stopCycle;
120 dprintf("stop before: %i", stop_before);
121 if (stop_before > 0 && stop_before <= 32) // Gens uses 16 here
122 d = 1; // bus not yet available
125 d=(d<<8)|0x8000|Pico.m.rotate++;
126 dprintf("get_zrun: %04x [%i|%i] @%06x", d, Pico.m.scanline, SekCyclesDone(), SekPc);
130 #ifndef _ASM_MEMORY_C
131 if ((a&0xe700e0)==0xc00000) { d=PicoVideoRead(a); goto end; }
134 d = OtherRead16End(a, realsize);
141 //extern UINT32 mz80GetRegisterValue(void *, UINT32);
143 #ifndef _ASM_CD_MEMORY_C
146 void OtherWrite8(u32 a,u32 d,int realsize)
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
153 // 6 button gamepad: if TH went from 0 to 1, gamepad changes state
156 Pico.m.padDelay[0] = 0;
157 if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++;
160 Pico.m.padDelay[1] = 0;
161 if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++;
164 Pico.ioports[a]=(u8)d; // IO ports can be used as RAM
168 //int lineCycles=(488-SekCyclesLeft)&0x1ff;
171 // this is for a nasty situation where Z80 was enabled and disabled in the same 68k timeslice (Golden Axe III)
174 z80stopCycle = SekCyclesDone();
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);
185 z80startCycle = SekCyclesDone();
186 //if(Pico.m.scanline != -1)
188 dprintf("set_zrun: %02x [%i|%i] @%06x", d, Pico.m.scanline, SekCyclesDone(), /*mz80GetRegisterValue(NULL, 0),*/ SekPc);
189 Pico.m.z80Run=(u8)d; return;
192 dprintf("write z80Reset: %02x", d);
193 if(!(d&1)) z80_reset();
197 if ((a&0xff7f00)==0xa06000) // Z80 BANK register
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
205 if ((a&0xe700e0)==0xc00000) {
206 PicoVideoWrite(a,(u16)(d|(d<<8))); // Byte access gets mirrored
210 OtherWrite8End(a, d, realsize);
214 #ifndef _ASM_CD_MEMORY_C
217 void OtherWrite16(u32 a,u32 d)
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)
222 if ((a&0xffffe0)==0xa10000) { // I/O ports
224 // 6 button gamepad: if TH went from 0 to 1, gamepad changes state
227 Pico.m.padDelay[0] = 0;
228 if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++;
231 Pico.m.padDelay[1] = 0;
232 if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++;
235 Pico.ioports[a]=(u8)d; // IO ports can be used as RAM
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; }
241 OtherWrite8(a, d>>8, 16);
242 OtherWrite8(a+1,d&0xff, 16);