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- // common code for Memory.c and cd/Memory.c
- // (c) Copyright 2006-2007, Grazvydas "notaz" Ignotas
- #ifndef UTYPES_DEFINED
- typedef unsigned char u8;
- typedef unsigned short u16;
- typedef unsigned int u32;
- #define UTYPES_DEFINED
- #endif
- #ifndef _ASM_MEMORY_C
- static
- #endif
- u8 z80Read8(u32 a)
- {
- if(Pico.m.z80Run&1) return 0;
- a&=0x1fff;
- if (!(PicoOpt&POPT_EN_Z80))
- {
- // Z80 disabled, do some faking
- static u8 zerosent = 0;
- if(a == Pico.m.z80_lastaddr) { // probably polling something
- u8 d = Pico.m.z80_fakeval;
- if((d & 0xf) == 0xf && !zerosent) {
- d = 0; zerosent = 1;
- } else {
- Pico.m.z80_fakeval++;
- zerosent = 0;
- }
- return d;
- } else {
- Pico.m.z80_fakeval = 0;
- }
- }
- Pico.m.z80_lastaddr = (u16) a;
- return Pico.zram[a];
- }
- #ifndef _ASM_MEMORY_C
- static
- #endif
- u32 z80ReadBusReq(void)
- {
- u32 d=Pico.m.z80Run&1;
- if (!d) {
- // needed by buggy Terminator (Sega CD)
- int stop_before = SekCyclesDone() - z80stopCycle;
- //elprintf(EL_BUSREQ, "get_zrun: stop before: %i", stop_before);
- // note: if we use 20 or more here, Barkley Shut Up and Jam! will purposedly crash itself.
- // but CD Terminator needs at least 32, so it only works because next frame cycle wrap.
- if (stop_before > 0 && stop_before < 20) // Gens uses 16 here
- d = 1; // bus not yet available
- }
- elprintf(EL_BUSREQ, "get_zrun: %02x [%i] @%06x", d|0x80, SekCyclesDone(), SekPc);
- return d|0x80;
- }
- static void z80WriteBusReq(u32 d)
- {
- d&=1; d^=1;
- elprintf(EL_BUSREQ, "set_zrun: %i->%i [%i] @%06x", Pico.m.z80Run, d, SekCyclesDone(), SekPc);
- if (d ^ Pico.m.z80Run)
- {
- if (d)
- {
- z80_cycle_cnt = cycles_68k_to_z80(SekCyclesDone());
- }
- else
- {
- z80stopCycle = SekCyclesDone();
- if ((PicoOpt&POPT_EN_Z80) && !Pico.m.z80_reset)
- PicoSyncZ80(z80stopCycle);
- }
- Pico.m.z80Run=d;
- }
- }
- static void z80WriteReset(u32 d)
- {
- d&=1; d^=1;
- elprintf(EL_BUSREQ, "set_zreset: %i->%i [%i] @%06x", Pico.m.z80_reset, d, SekCyclesDone(), SekPc);
- if (d ^ Pico.m.z80_reset)
- {
- if (d)
- {
- if ((PicoOpt&POPT_EN_Z80) && Pico.m.z80Run)
- PicoSyncZ80(SekCyclesDone());
- }
- else
- {
- z80_cycle_cnt = cycles_68k_to_z80(SekCyclesDone());
- z80_reset();
- }
- YM2612ResetChip();
- timers_reset();
- Pico.m.z80_reset=d;
- }
- }
- #ifndef _ASM_MEMORY_C
- static
- #endif
- u32 OtherRead16(u32 a, int realsize)
- {
- u32 d=0;
- if ((a&0xffffe0)==0xa10000) { // I/O ports
- a=(a>>1)&0xf;
- switch(a) {
- case 0: d=Pico.m.hardware; break; // Hardware value (Version register)
- case 1: d=PadRead(0); break;
- case 2: d=PadRead(1); break;
- default: d=Pico.ioports[a]; break; // IO ports can be used as RAM
- }
- d|=d<<8;
- goto end;
- }
- // rotate fakes next fetched instruction for Time Killers
- if (a==0xa11100) { // z80 busreq
- d=(z80ReadBusReq()<<8)|Pico.m.rotate++;
- goto end;
- }
- if ((a&0xff0000)==0xa00000)
- {
- if (Pico.m.z80Run&1)
- elprintf(EL_ANOMALY, "68k z80 read with no bus! [%06x] @ %06x", a, SekPc);
- if ((a&0x4000)==0x0000) { d=z80Read8(a); d|=d<<8; goto end; } // Z80 ram (not byteswaped)
- if ((a&0x6000)==0x4000) { d=ym2612_read_local_68k(); goto end; } // 0x4000-0x5fff
- elprintf(EL_ANOMALY, "68k bad read [%06x]", a);
- d=0xffff;
- goto end;
- }
- d = PicoRead16Hook(a, realsize);
- end:
- return d;
- }
- static void IoWrite8(u32 a, u32 d)
- {
- a=(a>>1)&0xf;
- // 6 button gamepad: if TH went from 0 to 1, gamepad changes state
- if (PicoOpt&POPT_6BTN_PAD)
- {
- if (a==1) {
- Pico.m.padDelay[0] = 0;
- if(!(Pico.ioports[1]&0x40) && (d&0x40)) Pico.m.padTHPhase[0]++;
- }
- else if (a==2) {
- Pico.m.padDelay[1] = 0;
- if(!(Pico.ioports[2]&0x40) && (d&0x40)) Pico.m.padTHPhase[1]++;
- }
- }
- Pico.ioports[a]=(u8)d; // IO ports can be used as RAM
- }
- #ifndef _ASM_CD_MEMORY_C
- static
- #endif
- void OtherWrite8(u32 a,u32 d)
- {
- #if !defined(_ASM_MEMORY_C) || defined(_ASM_MEMORY_C_AMIPS)
- if ((a&0xe700f9)==0xc00011||(a&0xff7ff9)==0xa07f11) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound
- if ((a&0xff4000)==0xa00000) { // z80 RAM
- SekCyclesBurn(2); // hack
- if (!(Pico.m.z80Run&1) && !Pico.m.z80_reset) Pico.zram[a&0x1fff]=(u8)d;
- else elprintf(EL_ANOMALY, "68k z80 write with no bus or reset! [%06x] %02x @ %06x", a, d&0xff, SekPc);
- return;
- }
- if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=ym2612_write_local(a&3, d&0xff, 0)&1; return; } // FM Sound
- if ((a&0xffffe0)==0xa10000) { IoWrite8(a, d); return; } // I/O ports
- #endif
- if (a==0xa11100) { z80WriteBusReq(d); return; }
- if (a==0xa11200) { z80WriteReset(d); return; }
- #if !defined(_ASM_MEMORY_C) || defined(_ASM_MEMORY_C_AMIPS)
- if ((a&0xff7f00)==0xa06000) // Z80 BANK register
- {
- Pico.m.z80_bank68k>>=1;
- Pico.m.z80_bank68k|=(d&1)<<8;
- Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one
- elprintf(EL_Z80BNK, "z80 bank=%06x", Pico.m.z80_bank68k<<15);
- return;
- }
- #endif
- if ((a&0xe700e0)==0xc00000) {
- d&=0xff;
- PicoVideoWrite(a,(u16)(d|(d<<8))); // Byte access gets mirrored
- return;
- }
- PicoWrite8Hook(a, d&0xff, 8);
- }
- #ifndef _ASM_CD_MEMORY_C
- static
- #endif
- void OtherWrite16(u32 a,u32 d)
- {
- if (a==0xa11100) { z80WriteBusReq(d>>8); return; }
- if ((a&0xffffe0)==0xa10000) { IoWrite8(a, d); return; } // I/O ports
- if ((a&0xe700f8)==0xc00010||(a&0xff7ff8)==0xa07f10) { if(PicoOpt&2) SN76496Write(d); return; } // PSG Sound
- if ((a&0xff6000)==0xa04000) { if(PicoOpt&1) emustatus|=ym2612_write_local(a&3, d&0xff, 0)&1; return; } // FM Sound
- if ((a&0xff4000)==0xa00000) { // Z80 ram (MSB only)
- if (!(Pico.m.z80Run&1) && !Pico.m.z80_reset) Pico.zram[a&0x1fff]=(u8)(d>>8);
- else elprintf(EL_ANOMALY, "68k z80 write with no bus or reset! [%06x] %04x @ %06x", a, d&0xffff, SekPc);
- return;
- }
- if (a==0xa11200) { z80WriteReset(d>>8); return; }
- if ((a&0xff7f00)==0xa06000) // Z80 BANK register
- {
- Pico.m.z80_bank68k>>=1;
- Pico.m.z80_bank68k|=(d&1)<<8;
- Pico.m.z80_bank68k&=0x1ff; // 9 bits and filled in the new top one
- elprintf(EL_Z80BNK, "z80 bank=%06x", Pico.m.z80_bank68k<<15);
- return;
- }
- #ifndef _CD_MEMORY_C
- if (a >= SRam.start && a <= SRam.end) {
- elprintf(EL_SRAMIO, "sram w16 [%06x] %04x @ %06x", a, d, SekPc);
- if ((Pico.m.sram_reg&0x16)==0x10) { // detected, not EEPROM, write not disabled
- u8 *pm=(u8 *)(SRam.data-SRam.start+a);
- *pm++=d>>8;
- *pm++=d;
- SRam.changed = 1;
- }
- else
- SRAMWrite(a, d);
- return;
- }
- #endif
- PicoWrite16Hook(a, d&0xffff, 16);
- }
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