bsnes/higan/sfc/coprocessor/hitachidsp/memory.cpp

auto HitachiDSP::read(uint24 addr) -> uint8 {
  if((addr & 0x40ec00) == 0x006c00) {  //$00-3f,80-bf:6c00-6cff,7c00-7cff
    return dspRead(addr, 0x00);
  }
  if((addr & 0x40e000) == 0x006000) {  //$00-3f,80-bf:6000-6bff,7000-7bff
    return dramRead(addr, 0x00);
  }
  if((addr & 0x408000) == 0x008000) {  //$00-3f,80-bf:8000-ffff
    if(rom.size() == 0) return 0x00;
    addr = ((addr & 0x3f0000) >> 1) | (addr & 0x7fff);
    addr = Bus::mirror(addr, rom.size());
    return rom.read(addr, 0);
  }
  if((addr & 0xf88000) == 0x700000) {  //$70-77:0000-7fff
    if(ram.size() == 0) return 0x00;
    addr = ((addr & 0x070000) >> 1) | (addr & 0x7fff);
    addr = Bus::mirror(addr, ram.size());
    return ram.read(addr);
  }
  return 0x00;
}

auto HitachiDSP::write(uint24 addr, uint8 data) -> void {
  if((addr & 0x40ec00) == 0x006c00) {  //$00-3f,80-bf:6c00-6fff,7c00-7fff
    return dspWrite(addr, data);
  }
  if((addr & 0x40e000) == 0x006000) {  //$00-3f,80-bf:6000-6bff,7000-7bff
    return dramWrite(addr, data);
  }
  if((addr & 0xf88000) == 0x700000) {  //$70-77:0000-7fff
    if(ram.size() == 0) return;
    addr = ((addr & 0x070000) >> 1) | (addr & 0x7fff);
    addr = Bus::mirror(addr, ram.size());
    return ram.write(addr, data);
  }
}

auto HitachiDSP::romRead(uint24 addr, uint8 data) -> uint8 {
  if(hitachidsp.active() || regs.halt) {
    addr = Bus::mirror(addr, rom.size());
  //if(Roms == 2 && mmio.r1f52 == 1 && addr >= (bit::round(rom.size()) >> 1)) return 0x00;
    return rom.read(addr, data);
  }
  if((addr & 0x40ffe0) == 0x00ffe0) return mmio.vector[addr & 0x1f];
  return data;
}

auto HitachiDSP::romWrite(uint24 addr, uint8 data) -> void {
}

auto HitachiDSP::ramRead(uint24 addr, uint8 data) -> uint8 {
  if(ram.size() == 0) return 0x00;  //not open bus
  return ram.read(Bus::mirror(addr, ram.size()), data);
}

auto HitachiDSP::ramWrite(uint24 addr, uint8 data) -> void {
  if(ram.size() == 0) return;
  return ram.write(Bus::mirror(addr, ram.size()), data);
}

auto HitachiDSP::dramRead(uint24 addr, uint8 data) -> uint8 {
  addr &= 0xfff;
  if(addr >= 0xc00) return data;
  return dataRAM[addr];
}

auto HitachiDSP::dramWrite(uint24 addr, uint8 data) -> void {
  addr &= 0xfff;
  if(addr >= 0xc00) return;
  dataRAM[addr] = data;
}

auto HitachiDSP::dspRead(uint24 addr, uint8) -> uint8 {
  addr = 0x7c00 | (addr & 0x03ff);

  //MMIO
  switch(addr) {
  case 0x7f40: return mmio.dmaSource >>  0;
  case 0x7f41: return mmio.dmaSource >>  8;
  case 0x7f42: return mmio.dmaSource >> 16;
  case 0x7f43: return mmio.dmaLength >>  0;
  case 0x7f44: return mmio.dmaLength >>  8;
  case 0x7f45: return mmio.dmaTarget >>  0;
  case 0x7f46: return mmio.dmaTarget >>  8;
  case 0x7f47: return mmio.dmaTarget >> 16;
  case 0x7f48: return mmio.r1f48;
  case 0x7f49: return mmio.programOffset >>  0;
  case 0x7f4a: return mmio.programOffset >>  8;
  case 0x7f4b: return mmio.programOffset >> 16;
  case 0x7f4c: return mmio.r1f4c;
  case 0x7f4d: return mmio.pageNumber >> 0;
  case 0x7f4e: return mmio.pageNumber >> 8;
  case 0x7f4f: return mmio.programCounter;
  case 0x7f50: return mmio.r1f50;
  case 0x7f51: return mmio.r1f51;
  case 0x7f52: return mmio.r1f52;
  case 0x7f53: case 0x7f54: case 0x7f55: case 0x7f56:
  case 0x7f57: case 0x7f58: case 0x7f59: case 0x7f5a:
  case 0x7f5b: case 0x7f5c: case 0x7f5d: case 0x7f5e:
  case 0x7f5f: return ((regs.halt == false) << 6) | ((regs.halt == true) << 1);
  }

  //Vector
  if(addr >= 0x7f60 && addr <= 0x7f7f) {
    return mmio.vector[addr & 0x1f];
  }

  //GPRs
  if((addr >= 0x7f80 && addr <= 0x7faf) || (addr >= 0x7fc0 && addr <= 0x7fef)) {
    uint index = (addr & 0x3f) / 3;        //0..15
    uint shift = ((addr & 0x3f) % 3) * 8;  //0, 8, 16
    return regs.gpr[index] >> shift;
  }

  return 0x00;
}

auto HitachiDSP::dspWrite(uint24 addr, uint8 data) -> void {
  addr = 0x7c00 | (addr & 0x03ff);

  //MMIO
  switch(addr) {
  case 0x7f40: mmio.dmaSource = (mmio.dmaSource & 0xffff00) | (data <<  0); return;
  case 0x7f41: mmio.dmaSource = (mmio.dmaSource & 0xff00ff) | (data <<  8); return;
  case 0x7f42: mmio.dmaSource = (mmio.dmaSource & 0x00ffff) | (data << 16); return;
  case 0x7f43: mmio.dmaLength = (mmio.dmaLength &   0xff00) | (data <<  0); return;
  case 0x7f44: mmio.dmaLength = (mmio.dmaLength &   0x00ff) | (data <<  8); return;
  case 0x7f45: mmio.dmaTarget = (mmio.dmaTarget & 0xffff00) | (data <<  0); return;
  case 0x7f46: mmio.dmaTarget = (mmio.dmaTarget & 0xff00ff) | (data <<  8); return;
  case 0x7f47: mmio.dmaTarget = (mmio.dmaTarget & 0x00ffff) | (data << 16);
    if(regs.halt) mmio.dma = true;
    return;
  case 0x7f48: mmio.r1f48 = data & 0x01; return;
  case 0x7f49: mmio.programOffset = (mmio.programOffset & 0xffff00) | (data <<  0); return;
  case 0x7f4a: mmio.programOffset = (mmio.programOffset & 0xff00ff) | (data <<  8); return;
  case 0x7f4b: mmio.programOffset = (mmio.programOffset & 0x00ffff) | (data << 16); return;
  case 0x7f4c: mmio.r1f4c = data & 0x03; return;
  case 0x7f4d: mmio.pageNumber = (mmio.pageNumber & 0x7f00) | ((data & 0xff) << 0); return;
  case 0x7f4e: mmio.pageNumber = (mmio.pageNumber & 0x00ff) | ((data & 0x7f) << 8); return;
  case 0x7f4f: mmio.programCounter = data;
    if(regs.halt) {
      regs.pc = mmio.pageNumber * 256 + mmio.programCounter;
      regs.halt = false;
    }
    return;
  case 0x7f50: mmio.r1f50 = data & 0x77; return;
  case 0x7f51: mmio.r1f51 = data & 0x01; return;
  case 0x7f52: mmio.r1f52 = data & 0x01; return;
  }

  //Vector
  if(addr >= 0x7f60 && addr <= 0x7f7f) {
    mmio.vector[addr & 0x1f] = data;
    return;
  }

  //GPRs
  if((addr >= 0x7f80 && addr <= 0x7faf) || (addr >= 0x7fc0 && addr <= 0x7fef)) {
    uint index = (addr & 0x3f) / 3;
    switch((addr & 0x3f) % 3) {
    case 0: regs.gpr[index] = (regs.gpr[index] & 0xffff00) | (data <<  0); return;
    case 1: regs.gpr[index] = (regs.gpr[index] & 0xff00ff) | (data <<  8); return;
    case 2: regs.gpr[index] = (regs.gpr[index] & 0x00ffff) | (data << 16); return;
    }
  }
}