// CPI Compare Immediate With Accumulator
// The byte of immediate data is compared to the contents of the accumulator.
private int CPI(byte b)
{
var cmp16 = Accumulator - b;
Flags = Flags
.Set(FlagIndex.Carry, ((cmp16 & 0x00FF) >= Accumulator && b != 0))
.Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_subAC(Accumulator, b))
.calc_SZP((byte)cmp16);
return(7);
}
// Compare
private int CMP(IByteOperandStrategy operand)
{
var cmp16 = Accumulator - operand.Read(this);
Flags = Flags
.Set(FlagIndex.Carry, ((cmp16 & 0x00FF) >= Accumulator && operand.Read(this) != 0))
.Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_subAC(Accumulator, operand.Read(this)))
.calc_SZP((byte)cmp16);
return(operand == OpMem ? 7 : 4);
}
// INR Increment Register or Memory
// If register C contains 99H, the instruction: INR C will cause register C to contain 9AH
private int INR(IByteOperandStrategy op)
{
var in8 = op.Read(this);
var out8 = (byte)(in8 + 1);
Flags = Flags
.Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_AC(in8, 1))
.calc_SZP(out8);
op.Write(this, out8);
return(op == OpMem ? 10 : 5);
}
//SUI Subtract Immediate From Accumulator
// The byte of immediate data is subtracted from the contents of the accumulator using two's complement arithmetic.
private int SUI(byte b)
{
var out16 = (ushort)(Accumulator - b);
Flags = Flags
.Set(FlagIndex.Carry, ((out16 & 0x00FF) >= Accumulator && b != 0))
.Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_subAC(Accumulator, b))
.calc_SZP((byte)out16);
Accumulator = (byte)out16;
return(7);
}
// SUB Subtract Register or Memory From Accumulator
private int SUB(IByteOperandStrategy operand)
{
var in8 = operand.Read(this);
var out16 = Accumulator - in8;
Flags = Flags
.Set(FlagIndex.Carry, ((out16 & 0x00FF) >= Accumulator && in8 != 0))
.Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_subAC(Accumulator, in8))
.calc_SZP((byte)out16);
Accumulator = (byte)out16;
return(operand == OpMem ? 7 : 4);
}
// ADI Add Immediate To Accumulator
// The byte of immediate data is added to the contents of the accumulator using two's complement arithmetic.
private int ADI(byte b)
{
var out16 = Accumulator + b;
Flags = Flags
.Set(FlagIndex.Carry, ((out16 & 0xFF00) != 0)).Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_AC(Accumulator, b))
.calc_SZP((byte)out16);
Accumulator = (byte)out16;
return(7);
}