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added ppu register access

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Lauchmelder 2021-10-23 20:16:29 +02:00
parent 19d138fb5f
commit 7c0957325f
7 changed files with 113 additions and 19 deletions
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78
NES Emulator/ppu.c
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@ -54,12 +54,17 @@ struct PPU* createPPU(struct Bus* parent)
exit(1);
}
ppu->ppuctrl.raw = 0b00000000;
ppu->ppumask.raw = 0b00000000;
ppu->ppustatus.raw = 0b10100000;
ppu->ppuCtrl.raw = 0b00000000;
ppu->ppuMask.raw = 0b00000000;
ppu->ppuStatus.raw = 0b10100000;
ppu->oamaddr = 0x00;
ppu->ppuAddr = 0x00;
ppu->ppuData = 0x00;
ppu->scrollX = 0;
ppu->scrollY = 0;
ppu->scrollWriteTarget = 0;
ppu->ppuAddress.raw = 0x00;
ppu->ppuAddressWriteTarget = 0;
ppu->x = 0;
ppu->y = 0;
@ -79,11 +84,72 @@ void destroyPPU(struct PPU* ppu)
Byte ppuRead(struct PPU* ppu, Word addr)
{
return 0x00;
Byte val = 0x00;
switch (addr)
{
case 0x2000:
break;
case 0x2001:
break;
case 0x2002:
val = ppu->ppuStatus.raw;
break;
case 0x2005:
break;
case 0x2006:
break;
case 0x2007:
val = ppu->nametables[ppu->ppuAddress.raw & 0x2000][ppu->ppuAddress.raw & 0x1FFF];
ppu->ppuAddress.raw += ppu->ppuCtrl.increment;
break;
default:
fprintf(stderr, "Read access violation at PPU register $%04X", addr);
exit(1);
}
return val;
}
void ppuWrite(struct PPU* ppu, Word addr, Byte val)
{
switch (addr)
{
case 0x2000:
ppu->ppuCtrl.raw = val;
break;
case 0x2001:
ppu->ppuMask.raw = val;
break;
case 0x2002:
break;
case 0x2005:
*((&ppu->scrollX) + ppu->scrollWriteTarget) = val;
ppu->scrollWriteTarget = 1 - ppu->scrollWriteTarget;
break;
case 0x2006:
*((&ppu->ppuAddress.lo) + ppu->ppuAddressWriteTarget) = val;
ppu->ppuAddressWriteTarget = 1 - ppu->ppuAddressWriteTarget;
break;
case 0x2007:
ppu->nametables[ppu->ppuAddress.raw & 0x2000][ppu->ppuAddress.raw & 0x1FFF] = val;
ppu->ppuAddress.raw += ppu->ppuCtrl.increment;
break;
default:
fprintf(stderr, "Write access violation at PPU register: $%04X", addr);
exit(1);
}
}
void tickPPU(struct PPU* ppu)