auto PPU::interlace() const -> bool {
  return display.interlace;
}

auto PPU::overscan() const -> bool {
  return display.overscan;
}

auto PPU::latch_counters() -> void {
  cpu.synchronizePPU();
  regs.hcounter = hdot();
  regs.vcounter = vcounter();
  regs.counters_latched = true;
}

auto PPU::get_vram_address() -> uint16 {
  uint16 addr = regs.vram_addr;
  switch(regs.vram_mapping) {
  case 0: break;  //direct mapping
  case 1: addr = (addr & 0xff00) | ((addr & 0x001f) << 3) | ((addr >> 5) & 7); break;
  case 2: addr = (addr & 0xfe00) | ((addr & 0x003f) << 3) | ((addr >> 6) & 7); break;
  case 3: addr = (addr & 0xfc00) | ((addr & 0x007f) << 3) | ((addr >> 7) & 7); break;
  }
  return (addr << 1);
}

auto PPU::vram_read(uint addr) -> uint8 {
  uint8 data = 0x00;
  if(regs.display_disable || vcounter() >= (!regs.overscan ? 225 : 240)) {
    data = vram[addr];
    debugger.vram_read(addr, data);
  }
  return data;
}

auto PPU::vram_write(uint addr, uint8 data) -> void {
  if(regs.display_disable || vcounter() >= (!regs.overscan ? 225 : 240)) {
    vram[addr] = data;
    debugger.vram_write(addr, data);
  }
}

auto PPU::oam_read(uint addr) -> uint8 {
  uint8 data = oam[addr];
  debugger.oam_read(addr, data);
  return data;
}

auto PPU::oam_write(uint addr, uint8 data) -> void {
  oam[addr] = data;
  sprite.update(addr, data);
  debugger.oam_write(addr, data);
}

auto PPU::cgram_read(uint addr) -> uint8 {
  uint8 data = cgram[addr];
  debugger.cgram_read(addr, data);
  return data;
}

auto PPU::cgram_write(uint addr, uint8 data) -> void {
  cgram[addr] = data;
  debugger.cgram_write(addr, data);
}

auto PPU::mmio_update_video_mode() -> void {
  switch(regs.bgmode) {
  case 0:
    bg1.regs.mode = Background::Mode::BPP2; bg1.regs.priority0 = 8; bg1.regs.priority1 = 11;
    bg2.regs.mode = Background::Mode::BPP2; bg2.regs.priority0 = 7; bg2.regs.priority1 = 10;
    bg3.regs.mode = Background::Mode::BPP2; bg3.regs.priority0 = 2; bg3.regs.priority1 =  5;
    bg4.regs.mode = Background::Mode::BPP2; bg4.regs.priority0 = 1; bg4.regs.priority1 =  4;
    sprite.regs.priority0 = 3; sprite.regs.priority1 = 6; sprite.regs.priority2 = 9; sprite.regs.priority3 = 12;
    break;

  case 1:
    bg1.regs.mode = Background::Mode::BPP4;
    bg2.regs.mode = Background::Mode::BPP4;
    bg3.regs.mode = Background::Mode::BPP2;
    bg4.regs.mode = Background::Mode::Inactive;
    if(regs.bg3_priority) {
      bg1.regs.priority0 = 5; bg1.regs.priority1 =  8;
      bg2.regs.priority0 = 4; bg2.regs.priority1 =  7;
      bg3.regs.priority0 = 1; bg3.regs.priority1 = 10;
      sprite.regs.priority0 = 2; sprite.regs.priority1 = 3; sprite.regs.priority2 = 6; sprite.regs.priority3 = 9;
    } else {
      bg1.regs.priority0 = 6; bg1.regs.priority1 =  9;
      bg2.regs.priority0 = 5; bg2.regs.priority1 =  8;
      bg3.regs.priority0 = 1; bg3.regs.priority1 =  3;
      sprite.regs.priority0 = 2; sprite.regs.priority1 = 4; sprite.regs.priority2 = 7; sprite.regs.priority3 = 10;
    }
    break;

  case 2:
    bg1.regs.mode = Background::Mode::BPP4;
    bg2.regs.mode = Background::Mode::BPP4;
    bg3.regs.mode = Background::Mode::Inactive;
    bg4.regs.mode = Background::Mode::Inactive;
    bg1.regs.priority0 = 3; bg1.regs.priority1 = 7;
    bg2.regs.priority0 = 1; bg2.regs.priority1 = 5;
    sprite.regs.priority0 = 2; sprite.regs.priority1 = 4; sprite.regs.priority2 = 6; sprite.regs.priority3 = 8;
    break;

  case 3:
    bg1.regs.mode = Background::Mode::BPP8;
    bg2.regs.mode = Background::Mode::BPP4;
    bg3.regs.mode = Background::Mode::Inactive;
    bg4.regs.mode = Background::Mode::Inactive;
    bg1.regs.priority0 = 3; bg1.regs.priority1 = 7;
    bg2.regs.priority0 = 1; bg2.regs.priority1 = 5;
    sprite.regs.priority0 = 2; sprite.regs.priority1 = 4; sprite.regs.priority2 = 6; sprite.regs.priority3 = 8;
    break;

  case 4:
    bg1.regs.mode = Background::Mode::BPP8;
    bg2.regs.mode = Background::Mode::BPP2;
    bg3.regs.mode = Background::Mode::Inactive;
    bg4.regs.mode = Background::Mode::Inactive;
    bg1.regs.priority0 = 3; bg1.regs.priority1 = 7;
    bg2.regs.priority0 = 1; bg2.regs.priority1 = 5;
    sprite.regs.priority0 = 2; sprite.regs.priority1 = 4; sprite.regs.priority2 = 6; sprite.regs.priority3 = 8;
    break;

  case 5:
    bg1.regs.mode = Background::Mode::BPP4;
    bg2.regs.mode = Background::Mode::BPP2;
    bg3.regs.mode = Background::Mode::Inactive;
    bg4.regs.mode = Background::Mode::Inactive;
    bg1.regs.priority0 = 3; bg1.regs.priority1 = 7;
    bg2.regs.priority0 = 1; bg2.regs.priority1 = 5;
    sprite.regs.priority0 = 2; sprite.regs.priority1 = 4; sprite.regs.priority2 = 6; sprite.regs.priority3 = 8;
    break;

  case 6:
    bg1.regs.mode = Background::Mode::BPP4;
    bg2.regs.mode = Background::Mode::Inactive;
    bg3.regs.mode = Background::Mode::Inactive;
    bg4.regs.mode = Background::Mode::Inactive;
    bg1.regs.priority0 = 2; bg1.regs.priority1 = 5;
    sprite.regs.priority0 = 1; sprite.regs.priority1 = 3; sprite.regs.priority2 = 4; sprite.regs.priority3 = 6;
    break;

  case 7:
    if(regs.mode7_extbg == false) {
      bg1.regs.mode = Background::Mode::Mode7;
      bg2.regs.mode = Background::Mode::Inactive;
      bg3.regs.mode = Background::Mode::Inactive;
      bg4.regs.mode = Background::Mode::Inactive;
      bg1.regs.priority0 = 2; bg1.regs.priority1 = 2;
      sprite.regs.priority0 = 1; sprite.regs.priority1 = 3; sprite.regs.priority2 = 4; sprite.regs.priority3 = 5;
    } else {
      bg1.regs.mode = Background::Mode::Mode7;
      bg2.regs.mode = Background::Mode::Mode7;
      bg3.regs.mode = Background::Mode::Inactive;
      bg4.regs.mode = Background::Mode::Inactive;
      bg1.regs.priority0 = 3; bg1.regs.priority1 = 3;
      bg2.regs.priority0 = 1; bg2.regs.priority1 = 5;
      sprite.regs.priority0 = 2; sprite.regs.priority1 = 4; sprite.regs.priority2 = 6; sprite.regs.priority3 = 7;
    }
    break;
  }
}

//INIDISP
auto PPU::mmio_w2100(uint8 data) -> void {
  if(regs.display_disable && vcounter() == (!regs.overscan ? 225 : 240)) sprite.address_reset();
  regs.display_disable = data & 0x80;
  regs.display_brightness = data & 0x0f;
}

//OBSEL
auto PPU::mmio_w2101(uint8 data) -> void {
  sprite.regs.base_size = (data >> 5) & 7;
  sprite.regs.nameselect = (data >> 3) & 3;
  sprite.regs.tiledata_addr = (data & 3) << 14;
}

//OAMADDL
auto PPU::mmio_w2102(uint8 data) -> void {
  regs.oam_baseaddr = (regs.oam_baseaddr & 0x0200) | (data << 1);
  sprite.address_reset();
}

//OAMADDH
auto PPU::mmio_w2103(uint8 data) -> void {
  regs.oam_priority = data & 0x80;
  regs.oam_baseaddr = ((data & 0x01) << 9) | (regs.oam_baseaddr & 0x01fe);
  sprite.address_reset();
}

//OAMDATA
auto PPU::mmio_w2104(uint8 data) -> void {
  bool latch = regs.oam_addr & 1;
  uint10 addr = regs.oam_addr++;
  if(regs.display_disable == false && vcounter() < (!regs.overscan ? 225 : 240)) addr = regs.oam_iaddr;
  if(addr & 0x0200) addr &= 0x021f;

  if(latch == 0) regs.oam_latchdata = data;
  if(addr & 0x0200) {
    oam_write(addr, data);
  } else if(latch == 1) {
    oam_write((addr & ~1) + 0, regs.oam_latchdata);
    oam_write((addr & ~1) + 1, data);
  }
  sprite.set_first_sprite();
}

//BGMODE
auto PPU::mmio_w2105(uint8 data) -> void {
  bg4.regs.tile_size = (data & 0x80);
  bg3.regs.tile_size = (data & 0x40);
  bg2.regs.tile_size = (data & 0x20);
  bg1.regs.tile_size = (data & 0x10);
  regs.bg3_priority = (data & 0x08);
  regs.bgmode = (data & 0x07);
  mmio_update_video_mode();
}

//MOSAIC
auto PPU::mmio_w2106(uint8 data) -> void {
  unsigned mosaic_size = (data >> 4) & 15;
  bg4.regs.mosaic = (data & 0x08 ? mosaic_size : 0);
  bg3.regs.mosaic = (data & 0x04 ? mosaic_size : 0);
  bg2.regs.mosaic = (data & 0x02 ? mosaic_size : 0);
  bg1.regs.mosaic = (data & 0x01 ? mosaic_size : 0);
}

//BG1SC
auto PPU::mmio_w2107(uint8 data) -> void {
  bg1.regs.screen_addr = (data & 0x7c) << 9;
  bg1.regs.screen_size = data & 3;
}

//BG2SC
auto PPU::mmio_w2108(uint8 data) -> void {
  bg2.regs.screen_addr = (data & 0x7c) << 9;
  bg2.regs.screen_size = data & 3;
}

//BG3SC
auto PPU::mmio_w2109(uint8 data) -> void {
  bg3.regs.screen_addr = (data & 0x7c) << 9;
  bg3.regs.screen_size = data & 3;
}

//BG4SC
auto PPU::mmio_w210a(uint8 data) -> void {
  bg4.regs.screen_addr = (data & 0x7c) << 9;
  bg4.regs.screen_size = data & 3;
}

//BG12NBA
auto PPU::mmio_w210b(uint8 data) -> void {
  bg1.regs.tiledata_addr = (data & 0x07) << 13;
  bg2.regs.tiledata_addr = (data & 0x70) <<  9;
}

//BG34NBA
auto PPU::mmio_w210c(uint8 data) -> void {
  bg3.regs.tiledata_addr = (data & 0x07) << 13;
  bg4.regs.tiledata_addr = (data & 0x70) <<  9;
}

//BG1HOFS
auto PPU::mmio_w210d(uint8 data) -> void {
  regs.mode7_hoffset = (data << 8) | regs.mode7_latchdata;
  regs.mode7_latchdata = data;

  bg1.regs.hoffset = (data << 8) | (regs.bgofs_latchdata & ~7) | ((bg1.regs.hoffset >> 8) & 7);
  regs.bgofs_latchdata = data;
}

//BG1VOFS
auto PPU::mmio_w210e(uint8 data) -> void {
  regs.mode7_voffset = (data << 8) | regs.mode7_latchdata;
  regs.mode7_latchdata = data;

  bg1.regs.voffset = (data << 8) | regs.bgofs_latchdata;
  regs.bgofs_latchdata = data;
}

//BG2HOFS
auto PPU::mmio_w210f(uint8 data) -> void {
  bg2.regs.hoffset = (data << 8) | (regs.bgofs_latchdata & ~7) | ((bg2.regs.hoffset >> 8) & 7);
  regs.bgofs_latchdata = data;
}

//BG2VOFS
auto PPU::mmio_w2110(uint8 data) -> void {
  bg2.regs.voffset = (data << 8) | regs.bgofs_latchdata;
  regs.bgofs_latchdata = data;
}

//BG3HOFS
auto PPU::mmio_w2111(uint8 data) -> void {
  bg3.regs.hoffset = (data << 8) | (regs.bgofs_latchdata & ~7) | ((bg3.regs.hoffset >> 8) & 7);
  regs.bgofs_latchdata = data;
}

//BG3VOFS
auto PPU::mmio_w2112(uint8 data) -> void {
  bg3.regs.voffset = (data << 8) | regs.bgofs_latchdata;
  regs.bgofs_latchdata = data;
}

//BG4HOFS
auto PPU::mmio_w2113(uint8 data) -> void {
  bg4.regs.hoffset = (data << 8) | (regs.bgofs_latchdata & ~7) | ((bg4.regs.hoffset >> 8) & 7);
  regs.bgofs_latchdata = data;
}

//BG4VOFS
auto PPU::mmio_w2114(uint8 data) -> void {
  bg4.regs.voffset = (data << 8) | regs.bgofs_latchdata;
  regs.bgofs_latchdata = data;
}

//VMAIN
auto PPU::mmio_w2115(uint8 data) -> void {
  regs.vram_incmode = data & 0x80;
  regs.vram_mapping = (data >> 2) & 3;
  switch(data & 3) {
  case 0: regs.vram_incsize =   1; break;
  case 1: regs.vram_incsize =  32; break;
  case 2: regs.vram_incsize = 128; break;
  case 3: regs.vram_incsize = 128; break;
  }
}

//VMADDL
auto PPU::mmio_w2116(uint8 data) -> void {
  regs.vram_addr &= 0xff00;
  regs.vram_addr |= (data << 0);
  uint16 addr = get_vram_address();
  regs.vram_readbuffer  = vram_read(addr + 0) << 0;
  regs.vram_readbuffer |= vram_read(addr + 1) << 8;
}

//VMADDH
auto PPU::mmio_w2117(uint8 data) -> void {
  regs.vram_addr &= 0x00ff;
  regs.vram_addr |= (data << 8);
  uint16 addr = get_vram_address();
  regs.vram_readbuffer  = vram_read(addr + 0) << 0;
  regs.vram_readbuffer |= vram_read(addr + 1) << 8;
}

//VMDATAL
auto PPU::mmio_w2118(uint8 data) -> void {
  uint16 addr = get_vram_address() + 0;
  vram_write(addr, data);
  if(regs.vram_incmode == 0) regs.vram_addr += regs.vram_incsize;
}

//VMDATAH
auto PPU::mmio_w2119(uint8 data) -> void {
  uint16 addr = get_vram_address() + 1;
  vram_write(addr, data);
  if(regs.vram_incmode == 1) regs.vram_addr += regs.vram_incsize;
}

//M7SEL
auto PPU::mmio_w211a(uint8 data) -> void {
  regs.mode7_repeat = (data >> 6) & 3;
  regs.mode7_vflip = data & 0x02;
  regs.mode7_hflip = data & 0x01;
}

//M7A
auto PPU::mmio_w211b(uint8 data) -> void {
  regs.m7a = (data << 8) | regs.mode7_latchdata;
  regs.mode7_latchdata = data;
}

//M7B
auto PPU::mmio_w211c(uint8 data) -> void {
  regs.m7b = (data << 8) | regs.mode7_latchdata;
  regs.mode7_latchdata = data;
}

//M7C
auto PPU::mmio_w211d(uint8 data) -> void {
  regs.m7c = (data << 8) | regs.mode7_latchdata;
  regs.mode7_latchdata = data;
}

//M7D
auto PPU::mmio_w211e(uint8 data) -> void {
  regs.m7d = (data << 8) | regs.mode7_latchdata;
  regs.mode7_latchdata = data;
}

//M7X
auto PPU::mmio_w211f(uint8 data) -> void {
  regs.m7x = (data << 8) | regs.mode7_latchdata;
  regs.mode7_latchdata = data;
}

//M7Y
auto PPU::mmio_w2120(uint8 data) -> void {
  regs.m7y = (data << 8) | regs.mode7_latchdata;
  regs.mode7_latchdata = data;
}

//CGADD
auto PPU::mmio_w2121(uint8 data) -> void {
  regs.cgram_addr = data << 1;
}

//CGDATA
auto PPU::mmio_w2122(uint8 data) -> void {
  bool latch = regs.cgram_addr & 1;
  uint9 addr = regs.cgram_addr++;
  if(regs.display_disable == false
  && vcounter() > 0 && vcounter() < (!regs.overscan ? 225 : 240)
  && hcounter() >= 88 && hcounter() < 1096
  ) addr = regs.cgram_iaddr;

  if(latch == 0) {
    regs.cgram_latchdata = data;
  } else {
    cgram_write((addr & ~1) + 0, regs.cgram_latchdata);
    cgram_write((addr & ~1) + 1, data & 0x7f);
  }
}

//W12SEL
auto PPU::mmio_w2123(uint8 data) -> void {
  window.regs.bg2_two_enable = data & 0x80;
  window.regs.bg2_two_invert = data & 0x40;
  window.regs.bg2_one_enable = data & 0x20;
  window.regs.bg2_one_invert = data & 0x10;
  window.regs.bg1_two_enable = data & 0x08;
  window.regs.bg1_two_invert = data & 0x04;
  window.regs.bg1_one_enable = data & 0x02;
  window.regs.bg1_one_invert = data & 0x01;
}

//W34SEL
auto PPU::mmio_w2124(uint8 data) -> void {
  window.regs.bg4_two_enable = data & 0x80;
  window.regs.bg4_two_invert = data & 0x40;
  window.regs.bg4_one_enable = data & 0x20;
  window.regs.bg4_one_invert = data & 0x10;
  window.regs.bg3_two_enable = data & 0x08;
  window.regs.bg3_two_invert = data & 0x04;
  window.regs.bg3_one_enable = data & 0x02;
  window.regs.bg3_one_invert = data & 0x01;
}

//WOBJSEL
auto PPU::mmio_w2125(uint8 data) -> void {
  window.regs.col_two_enable = data & 0x80;
  window.regs.col_two_invert = data & 0x40;
  window.regs.col_one_enable = data & 0x20;
  window.regs.col_one_invert = data & 0x10;
  window.regs.oam_two_enable = data & 0x08;
  window.regs.oam_two_invert = data & 0x04;
  window.regs.oam_one_enable = data & 0x02;
  window.regs.oam_one_invert = data & 0x01;
}

//WH0
auto PPU::mmio_w2126(uint8 data) -> void {
  window.regs.one_left = data;
}

//WH1
auto PPU::mmio_w2127(uint8 data) -> void {
  window.regs.one_right = data;
}

//WH2
auto PPU::mmio_w2128(uint8 data) -> void {
  window.regs.two_left = data;
}

//WH3
auto PPU::mmio_w2129(uint8 data) -> void {
  window.regs.two_right = data;
}

//WBGLOG
auto PPU::mmio_w212a(uint8 data) -> void {
  window.regs.bg4_mask = (data >> 6) & 3;
  window.regs.bg3_mask = (data >> 4) & 3;
  window.regs.bg2_mask = (data >> 2) & 3;
  window.regs.bg1_mask = (data >> 0) & 3;
}

//WOBJLOG
auto PPU::mmio_w212b(uint8 data) -> void {
  window.regs.col_mask = (data >> 2) & 3;
  window.regs.oam_mask = (data >> 0) & 3;
}

//TM
auto PPU::mmio_w212c(uint8 data) -> void {
  sprite.regs.main_enable = data & 0x10;
  bg4.regs.main_enable = data & 0x08;
  bg3.regs.main_enable = data & 0x04;
  bg2.regs.main_enable = data & 0x02;
  bg1.regs.main_enable = data & 0x01;
}

//TS
auto PPU::mmio_w212d(uint8 data) -> void {
  sprite.regs.sub_enable = data & 0x10;
  bg4.regs.sub_enable = data & 0x08;
  bg3.regs.sub_enable = data & 0x04;
  bg2.regs.sub_enable = data & 0x02;
  bg1.regs.sub_enable = data & 0x01;
}

//TMW
auto PPU::mmio_w212e(uint8 data) -> void {
  window.regs.oam_main_enable = data & 0x10;
  window.regs.bg4_main_enable = data & 0x08;
  window.regs.bg3_main_enable = data & 0x04;
  window.regs.bg2_main_enable = data & 0x02;
  window.regs.bg1_main_enable = data & 0x01;
}

//TSW
auto PPU::mmio_w212f(uint8 data) -> void {
  window.regs.oam_sub_enable = data & 0x10;
  window.regs.bg4_sub_enable = data & 0x08;
  window.regs.bg3_sub_enable = data & 0x04;
  window.regs.bg2_sub_enable = data & 0x02;
  window.regs.bg1_sub_enable = data & 0x01;
}

//CGWSEL
auto PPU::mmio_w2130(uint8 data) -> void {
  window.regs.col_main_mask = (data >> 6) & 3;
  window.regs.col_sub_mask = (data >> 4) & 3;
  screen.regs.addsub_mode = data & 0x02;
  screen.regs.direct_color = data & 0x01;
}

//CGADDSUB
auto PPU::mmio_w2131(uint8 data) -> void {
  screen.regs.color_mode = data & 0x80;
  screen.regs.color_halve = data & 0x40;
  screen.regs.back_color_enable = data & 0x20;
  screen.regs.oam_color_enable = data & 0x10;
  screen.regs.bg4_color_enable = data & 0x08;
  screen.regs.bg3_color_enable = data & 0x04;
  screen.regs.bg2_color_enable = data & 0x02;
  screen.regs.bg1_color_enable = data & 0x01;
}

//COLDATA
auto PPU::mmio_w2132(uint8 data) -> void {
  if(data & 0x80) screen.regs.color_b = data & 0x1f;
  if(data & 0x40) screen.regs.color_g = data & 0x1f;
  if(data & 0x20) screen.regs.color_r = data & 0x1f;
}

//SETINI
auto PPU::mmio_w2133(uint8 data) -> void {
  regs.mode7_extbg = data & 0x40;
  regs.pseudo_hires = data & 0x08;
  regs.overscan = data & 0x04;
  sprite.regs.interlace = data & 0x02;
  regs.interlace = data & 0x01;
  mmio_update_video_mode();
}

//MPYL
auto PPU::mmio_r2134() -> uint8 {
  unsigned result = ((int16)regs.m7a * (int8)(regs.m7b >> 8));
  regs.ppu1_mdr = (result >>  0);
  return regs.ppu1_mdr;
}

//MPYM
auto PPU::mmio_r2135() -> uint8 {
  unsigned result = ((int16)regs.m7a * (int8)(regs.m7b >> 8));
  regs.ppu1_mdr = (result >>  8);
  return regs.ppu1_mdr;
}

//MPYH
auto PPU::mmio_r2136() -> uint8 {
  unsigned result = ((int16)regs.m7a * (int8)(regs.m7b >> 8));
  regs.ppu1_mdr = (result >> 16);
  return regs.ppu1_mdr;
}

//SLHV
auto PPU::mmio_r2137() -> uint8 {
  if(cpu.pio() & 0x80) latch_counters();
  return cpu.regs.mdr;
}

//OAMDATAREAD
auto PPU::mmio_r2138() -> uint8 {
  uint10 addr = regs.oam_addr++;
  if(regs.display_disable == false && vcounter() < (!regs.overscan ? 225 : 240)) addr = regs.oam_iaddr;
  if(addr & 0x0200) addr &= 0x021f;

  regs.ppu1_mdr = oam_read(addr);
  sprite.set_first_sprite();
  return regs.ppu1_mdr;
}

//VMDATALREAD
auto PPU::mmio_r2139() -> uint8 {
  uint16 addr = get_vram_address() + 0;
  regs.ppu1_mdr = regs.vram_readbuffer >> 0;
  if(regs.vram_incmode == 0) {
    addr &= ~1;
    regs.vram_readbuffer  = vram_read(addr + 0) << 0;
    regs.vram_readbuffer |= vram_read(addr + 1) << 8;
    regs.vram_addr += regs.vram_incsize;
  }
  return regs.ppu1_mdr;
}

//VMDATAHREAD
auto PPU::mmio_r213a() -> uint8 {
  uint16 addr = get_vram_address() + 1;
  regs.ppu1_mdr = regs.vram_readbuffer >> 8;
  if(regs.vram_incmode == 1) {
    addr &= ~1;
    regs.vram_readbuffer  = vram_read(addr + 0) << 0;
    regs.vram_readbuffer |= vram_read(addr + 1) << 8;
    regs.vram_addr += regs.vram_incsize;
  }
  return regs.ppu1_mdr;
}

//CGDATAREAD
auto PPU::mmio_r213b() -> uint8 {
  bool latch = regs.cgram_addr & 1;
  uint9 addr = regs.cgram_addr++;
  if(regs.display_disable == false
  && vcounter() > 0 && vcounter() < (!regs.overscan ? 225 : 240)
  && hcounter() >= 88 && hcounter() < 1096
  ) addr = regs.cgram_iaddr;

  if(latch == 0) {
    regs.ppu2_mdr  = cgram_read(addr);
  } else {
    regs.ppu2_mdr &= 0x80;
    regs.ppu2_mdr |= cgram_read(addr);
  }
  return regs.ppu2_mdr;
}

//OPHCT
auto PPU::mmio_r213c() -> uint8 {
  if(regs.latch_hcounter == 0) {
    regs.ppu2_mdr  = (regs.hcounter >> 0);
  } else {
    regs.ppu2_mdr &= 0xfe;
    regs.ppu2_mdr |= (regs.hcounter >> 8) & 1;
  }
  regs.latch_hcounter ^= 1;
  return regs.ppu2_mdr;
}

//OPVCT
auto PPU::mmio_r213d() -> uint8 {
  if(regs.latch_vcounter == 0) {
    regs.ppu2_mdr  = (regs.vcounter >> 0);
  } else {
    regs.ppu2_mdr &= 0xfe;
    regs.ppu2_mdr |= (regs.vcounter >> 8) & 1;
  }
  regs.latch_vcounter ^= 1;
  return regs.ppu2_mdr;
}

//STAT77
auto PPU::mmio_r213e() -> uint8 {
  regs.ppu1_mdr &= 0x10;
  regs.ppu1_mdr |= sprite.regs.time_over << 7;
  regs.ppu1_mdr |= sprite.regs.range_over << 6;
  regs.ppu1_mdr |= ppu1_version & 0x0f;
  return regs.ppu1_mdr;
}

//STAT78
auto PPU::mmio_r213f() -> uint8 {
  regs.latch_hcounter = 0;
  regs.latch_vcounter = 0;

  regs.ppu2_mdr &= 0x20;
  regs.ppu2_mdr |= field() << 7;
  if((cpu.pio() & 0x80) == 0) {
    regs.ppu2_mdr |= 0x40;
  } else if(regs.counters_latched) {
    regs.ppu2_mdr |= 0x40;
    regs.counters_latched = false;
  }
  regs.ppu2_mdr |= (system.region() == System::Region::NTSC ? 0 : 1) << 4;
  regs.ppu2_mdr |= ppu2_version & 0x0f;
  return regs.ppu2_mdr;
}

auto PPU::mmio_reset() -> void {
  regs.ppu1_mdr = random(0xff);
  regs.ppu2_mdr = random(0xff);

  regs.vram_readbuffer = random(0x0000);
  regs.oam_latchdata = random(0x00);
  regs.cgram_latchdata = random(0x00);
  regs.bgofs_latchdata = random(0x00);
  regs.mode7_latchdata = random(0x00);
  regs.counters_latched = false;
  regs.latch_hcounter = 0;
  regs.latch_vcounter = 0;

  regs.oam_iaddr = 0x0000;
  regs.cgram_iaddr = 0x00;

  //$2100  INIDISP
  regs.display_disable = true;
  regs.display_brightness = 0;

  //$2102  OAMADDL
  //$2103  OAMADDH
  regs.oam_baseaddr = random(0x0000);
  regs.oam_addr = random(0x0000);
  regs.oam_priority = random(false);

  //$2105  BGMODE
  regs.bg3_priority = false;
  regs.bgmode = 0;

  //$210d  BG1HOFS
  regs.mode7_hoffset = random(0x0000);

  //$210e  BG1VOFS
  regs.mode7_voffset = random(0x0000);

  //$2115  VMAIN
  regs.vram_incmode = random(1);
  regs.vram_mapping = random(0);
  regs.vram_incsize = 1;

  //$2116  VMADDL
  //$2117  VMADDH
  regs.vram_addr = random(0x0000);

  //$211a  M7SEL
  regs.mode7_repeat = random(0);
  regs.mode7_vflip = random(false);
  regs.mode7_hflip = random(false);

  //$211b  M7A
  regs.m7a = random(0x0000);

  //$211c  M7B
  regs.m7b = random(0x0000);

  //$211d  M7C
  regs.m7c = random(0x0000);

  //$211e  M7D
  regs.m7d = random(0x0000);

  //$211f  M7X
  regs.m7x = random(0x0000);

  //$2120  M7Y
  regs.m7y = random(0x0000);

  //$2121  CGADD
  regs.cgram_addr = random(0x0000);

  //$2133  SETINI
  regs.mode7_extbg = random(false);
  regs.pseudo_hires = random(false);
  regs.overscan = false;
  regs.interlace = false;

  //$213c  OPHCT
  regs.hcounter = 0;

  //$213d  OPVCT
  regs.vcounter = 0;
}

auto PPU::mmio_read(uint addr, uint8 data) -> uint8 {
  cpu.synchronizePPU();

  switch(addr & 0xffff) {
  case 0x2104:
  case 0x2105:
  case 0x2106:
  case 0x2108:
  case 0x2109:
  case 0x210a:
  case 0x2114:
  case 0x2115:
  case 0x2116:
  case 0x2118:
  case 0x2119:
  case 0x211a:
  case 0x2124:
  case 0x2125:
  case 0x2126:
  case 0x2128:
  case 0x2129:
  case 0x212a: return regs.ppu1_mdr;
  case 0x2134: return mmio_r2134();  //MPYL
  case 0x2135: return mmio_r2135();  //MPYM
  case 0x2136: return mmio_r2136();  //MYPH
  case 0x2137: return mmio_r2137();  //SLHV
  case 0x2138: return mmio_r2138();  //OAMDATAREAD
  case 0x2139: return mmio_r2139();  //VMDATALREAD
  case 0x213a: return mmio_r213a();  //VMDATAHREAD
  case 0x213b: return mmio_r213b();  //CGDATAREAD
  case 0x213c: return mmio_r213c();  //OPHCT
  case 0x213d: return mmio_r213d();  //OPVCT
  case 0x213e: return mmio_r213e();  //STAT77
  case 0x213f: return mmio_r213f();  //STAT78
  }

  return data;
}

auto PPU::mmio_write(uint addr, uint8 data) -> void {
  cpu.synchronizePPU();

  switch(addr & 0xffff) {
  case 0x2100: return mmio_w2100(data);  //INIDISP
  case 0x2101: return mmio_w2101(data);  //OBSEL
  case 0x2102: return mmio_w2102(data);  //OAMADDL
  case 0x2103: return mmio_w2103(data);  //OAMADDH
  case 0x2104: return mmio_w2104(data);  //OAMDATA
  case 0x2105: return mmio_w2105(data);  //BGMODE
  case 0x2106: return mmio_w2106(data);  //MOSAIC
  case 0x2107: return mmio_w2107(data);  //BG1SC
  case 0x2108: return mmio_w2108(data);  //BG2SC
  case 0x2109: return mmio_w2109(data);  //BG3SC
  case 0x210a: return mmio_w210a(data);  //BG4SC
  case 0x210b: return mmio_w210b(data);  //BG12NBA
  case 0x210c: return mmio_w210c(data);  //BG34NBA
  case 0x210d: return mmio_w210d(data);  //BG1HOFS
  case 0x210e: return mmio_w210e(data);  //BG1VOFS
  case 0x210f: return mmio_w210f(data);  //BG2HOFS
  case 0x2110: return mmio_w2110(data);  //BG2VOFS
  case 0x2111: return mmio_w2111(data);  //BG3HOFS
  case 0x2112: return mmio_w2112(data);  //BG3VOFS
  case 0x2113: return mmio_w2113(data);  //BG4HOFS
  case 0x2114: return mmio_w2114(data);  //BG4VOFS
  case 0x2115: return mmio_w2115(data);  //VMAIN
  case 0x2116: return mmio_w2116(data);  //VMADDL
  case 0x2117: return mmio_w2117(data);  //VMADDH
  case 0x2118: return mmio_w2118(data);  //VMDATAL
  case 0x2119: return mmio_w2119(data);  //VMDATAH
  case 0x211a: return mmio_w211a(data);  //M7SEL
  case 0x211b: return mmio_w211b(data);  //M7A
  case 0x211c: return mmio_w211c(data);  //M7B
  case 0x211d: return mmio_w211d(data);  //M7C
  case 0x211e: return mmio_w211e(data);  //M7D
  case 0x211f: return mmio_w211f(data);  //M7X
  case 0x2120: return mmio_w2120(data);  //M7Y
  case 0x2121: return mmio_w2121(data);  //CGADD
  case 0x2122: return mmio_w2122(data);  //CGDATA
  case 0x2123: return mmio_w2123(data);  //W12SEL
  case 0x2124: return mmio_w2124(data);  //W34SEL
  case 0x2125: return mmio_w2125(data);  //WOBJSEL
  case 0x2126: return mmio_w2126(data);  //WH0
  case 0x2127: return mmio_w2127(data);  //WH1
  case 0x2128: return mmio_w2128(data);  //WH2
  case 0x2129: return mmio_w2129(data);  //WH3
  case 0x212a: return mmio_w212a(data);  //WBGLOG
  case 0x212b: return mmio_w212b(data);  //WOBJLOG
  case 0x212c: return mmio_w212c(data);  //TM
  case 0x212d: return mmio_w212d(data);  //TS
  case 0x212e: return mmio_w212e(data);  //TMW
  case 0x212f: return mmio_w212f(data);  //TSW
  case 0x2130: return mmio_w2130(data);  //CGWSEL
  case 0x2131: return mmio_w2131(data);  //CGADDSUB
  case 0x2132: return mmio_w2132(data);  //COLDATA
  case 0x2133: return mmio_w2133(data);  //SETINI
  }
}