/// <summary>
/// Writes one byte to the specified bank, at the specified offset
/// </summary>
/// <param name="memoryType"></param>
/// <param name="offset"></param>
/// <param name="data"></param>
public void WriteByte(int offset, byte data)
{
//CHR ROM
if (offset < 0x2000)
{
_chrRom[offset] = data;
return;
}
//PPU Interceptors
if (offset <= 0x3FFF || offset == 0x4014)
{
if (!WriteInterceptors.TryGetValue(offset, out currentWriteInterceptor))
{
return;
}
currentWriteInterceptor(offset, data);
return;
}
if (offset >= 0x8000 && offset <= 0xFFFF)
{
_prgRom[offset - 0x8000] = data;
return;
}
throw new ArgumentOutOfRangeException(nameof(offset), offset, "Maximum value of offset is 0xFFFF");
}
/// <summary>
/// Writes one byte to the specified bank, at the specified offset
/// </summary>
/// <param name="offset"></param>
/// <param name="data"></param>
public void WriteByte(int offset, byte data)
{
//CHR ROM+RAM Writes
if (offset < 0x2000)
{
_chrRom[offset] = data;
return;
}
//PPU Registers
if (offset <= 0x3FFF || offset == 0x4014)
{
if (WriteInterceptors.TryGetValue(offset, out currentWriteInterceptor))
{
currentWriteInterceptor(offset, data);
}
return;
}
//Some UxROM boards from Nintendo have bus conflicts, we avoid these here
if (offset >= 0x6000 && offset <= 0x7FFF)
{
return;
}
//Bank Select
if (offset >= 0xC000 && offset <= 0xFFFF)
{
_prgBank0Offset = (data & 0x0F) * 0x4000;
return;
}
throw new ArgumentOutOfRangeException(nameof(offset), offset, "Maximum value of offset is 0xFFFF");
}
/// <summary>
/// Writes one byte to the specified bank, at the specified offset
///
/// CHR Bank Switching is handled at $8000->$FFFF
/// </summary>
/// <param name="memoryType"></param>
/// <param name="offset"></param>
/// <param name="data"></param>
public void WriteByte(int offset, byte data)
{
//CHR ROM+RAM Writes
if (offset < 0x2000)
{
_chrRom[_chrRomOffset + offset] = data;
return;
}
//PPU Registers
if (offset <= 0x3FFF || offset == 0x4014)
{
if (WriteInterceptors.TryGetValue(offset, out currentWriteInterceptor))
{
currentWriteInterceptor(offset, data);
}
return;
}
//CHR Bank Select
if (offset >= 0x8000 && offset <= 0xFFFF)
{
_chrRomOffset = (data & 0x03) * 0x2000;
return;
}
throw new ArgumentOutOfRangeException(nameof(offset), offset, "Maximum value of offset is 0xFFFF");
}
/// <summary>
/// Writes one byte to the specified bank, at the specified offset
/// </summary>
/// <param name="memoryType"></param>
/// <param name="offset"></param>
/// <param name="data"></param>
public void WriteByte(int offset, byte data)
{
// CHR Bank 0 == $0000-$0FFF
// CHR Bank 1 == $1000-$1FFF
if (offset <= 0x1FFF)
{
if (!_useChrRam)
{
throw new AccessViolationException($"Invalid write to CHR ROM (CHR RAM not enabled). Offset: {offset:X4}");
}
var chrOffset = (offset / 0x1000) == 0 ? _chrBank0Offset : _chrBank1Offset;
chrOffset += offset % 0x1000;
_chrRom[chrOffset] = data;
return;
}
//PPU Registers
if (offset <= 0x3FFF || offset == 0x4014)
{
if (WriteInterceptors.TryGetValue(offset, out currentWriteInterceptor))
{
currentWriteInterceptor(offset, data);
}
return;
}
// PRG RAM Bank == $6000-$7FFF
if (offset >= 0x6000 && offset <= 0x7FFF)
{
if (!_usePrgRam)
{
throw new AccessViolationException($"Attempt to write PRG RAM when disabled. Offset ${offset:X4}");
}
_prgRam[offset - 0x6000] = data;
return;
}
//Writes to this range are handled by the Load Register
if (offset >= 0x8000 && offset <= 0xFFFF)
{
WriteLoadRegister(offset, data);
return;
}
//Sanity Check if we reach this point
throw new ArgumentOutOfRangeException(nameof(offset), "Maximum value of offset is 0xFFFF");
}
/// <summary>
/// Writes one byte to the specified bank, at the specified offset
/// </summary>
/// <param name="memoryType"></param>
/// <param name="offset"></param>
/// <param name="data"></param>
public void WriteByte(enumMemoryType memoryType, int offset, byte data)
{
switch (memoryType)
{
case enumMemoryType.CPU:
_prgRom[CpuOffsetToPrgRomOffset(offset)] = data;
return;
case enumMemoryType.PPU:
if (!WriteInterceptors.TryGetValue(offset, out currentWriteInterceptor))
{
_chrRom[offset] = data;
}
else
{
currentWriteInterceptor(offset, data);
}
return;
default:
throw new ArgumentOutOfRangeException(nameof(memoryType), memoryType, null);
}
}
