private static Operand ReadOperand(MemoryScanner scanner, byte type)
{
switch (type)
{
case 0x0: return(new Operand(OperandType.Constant, 0));
case 0x1: return(new Operand(OperandType.Constant, (uint)(sbyte)scanner.NextByte()));
case 0x2: return(new Operand(OperandType.Constant, (uint)(short)scanner.NextWord()));
case 0x3: return(new Operand(OperandType.Constant, scanner.NextDWord()));
case 0x5: return(new Operand(OperandType.Address, scanner.NextByte()));
case 0x6: return(new Operand(OperandType.Address, scanner.NextWord()));
case 0x7: return(new Operand(OperandType.Address, scanner.NextDWord()));
case 0x8: return(new Operand(OperandType.Stack, 0));
case 0x9: return(new Operand(OperandType.LocalAddress, scanner.NextByte()));
case 0xa: return(new Operand(OperandType.LocalAddress, scanner.NextWord()));
case 0xb: return(new Operand(OperandType.LocalAddress, scanner.NextDWord()));
case 0xd: return(new Operand(OperandType.RamAddress, scanner.NextByte()));
case 0xe: return(new Operand(OperandType.RamAddress, scanner.NextWord()));
case 0xf: return(new Operand(OperandType.RamAddress, scanner.NextDWord()));
default: throw new InvalidOperationException($"Invalid operand type byte: {type}");
}
}
private static uint ReadOpcodeNumber(MemoryScanner scanner)
{
var firstByte = scanner.PeekByte();
if ((firstByte & 0xC0) == 0xC0)
{
return(scanner.NextDWord() & 0x0fffffffu);
}
if ((firstByte & 0x80) == 0x80)
{
return(scanner.NextWord() & 0x3fffu);
}
return(scanner.NextByte() & 0x7fu);
}