private void load_xx_mmmm(IRegister <ushort> XX)
{
var addr = WordAtPCPlusInitialOpcodeLength;
XX.Value = Memory.GetWordAt(addr);
WZ.Value = addr;
WZ.Inc();
}
private void load_mmmm_xx(IRegister <ushort> XX)
{
var addr = WordAtPCPlusInitialOpcodeLength;
Memory.SetWordAt(WordAtPCPlusInitialOpcodeLength, XX.Value);
WZ.Value = addr;
WZ.Inc();
}
private void load_a_mmmm()
{
ushort addr = WordAtPCPlusInitialOpcodeLength;
A.Value = Memory[addr];
WZ.Value = addr;
WZ.Inc();
}
private void rrd()
{
int oldHlm = HLM.Value;
int newHlm = (oldHlm >> 4) | (A.Value << 4);
A.Value = (byte)((A.Value & 0xF0) | (oldHlm & 0x0F));
HLM.Value = (byte)newHlm;
F.Value = (byte)((F.Value & 0x01) | SZ53P(A.Value));
WZ.Value = HL.Value;
WZ.Inc();
}
private void lddr()
{
ldd();
if (BC.NZ)
{
NextPC -= 2;
RecordExtraTicks = true;
}
else
{
WZ.Value = PC.Value;
WZ.Inc();
}
}
private void sbc_hl(IRegister <ushort> r2)
{
WZ.Value = HL.Value;
WZ.Inc();
int cfVal = CF ? 1 : 0;
int diff = HL.Value - r2.Value - cfVal;
F.Value = (byte)(S_NF | (diff >> 8) & (S_SF | S_F5 | S_F3));
HF = ((HL.Value & 0x0FFF) - (r2.Value & 0x0FFF)) - cfVal < 0;
VF = ((r2.Value ^ HL.Value) & (HL.Value ^ diff) & 0x8000) != 0x0000;
ZF = diff == 0;
CF = diff < 0;
HL.Value = (ushort)diff;
}
private void add(IRegister <ushort> r1, IRegister <ushort> r2)
{
WZ.Value = r1.Value;
WZ.Inc();
int sum = r1.Value + r2.Value;
F.Value = (byte)(F.Value & (S_SF | S_ZF | S_VF));
HF = ((r1.Value & 0x0FFF) + (r2.Value & 0x0FFF)) > 0x0FFF;
F5 = ((sum >> 8) & S_F5) == S_F5;
F3 = ((sum >> 8) & S_F3) == S_F3;
CF = sum > 0xFFFF;
r1.Value = (ushort)sum;
}
private void adc_hl(IRegister <ushort> r)
{
WZ.Value = HL.Value;
WZ.Inc();
int cfVal = CF ? 1 : 0;
int sum = HL.Value + r.Value + cfVal;
F.Value = (byte)((sum >> 8) & (S_SF | S_F5 | S_F3));
HF = ((HL.Value & 0x0FFF) + (r.Value & 0x0FFF) + cfVal) > 0x0FFF;
VF = ((HL.Value ^ r.Value ^ 0x8000) & (r.Value ^ sum) & 0x8000) == 0x8000;
ZF = (sum & 0xFFFF) == 0;
CF = sum > 0xFFFF;
HL.Value = (ushort)sum;
}
private void cpxr()
{
/*
* https://www.omnimaga.org/asm-language/bit-n-(hl)-flags/5/?wap2
*
* WZ: when BC=1 or A=(HL): exactly as CPI/R
* In other cases WZ = PC + 1 on each step, where PC = instruction address.
* Note since at the last execution BC=1 or A=(HL), resulting MEMPTR = PC + 1 + 1
* (if there were not interrupts during the execution)
*/
if (BC.NZ && !ZF)
{
WZ.Value = PC.Value;
WZ.Inc();
RecordExtraTicks = true;
NextPC -= 2;
Debug.Assert(PC.Value == NextPC);
}
}
private void cpi()
{
WZ.Inc();
cpx();
HL.Inc();
}
private void OutPortA()
{
OutPort(C.Value, A.Value);
WZ.Value = BC.Value;
WZ.Inc();
}
private void outi()
{
outx(true);
WZ.Value = BC.Value;
WZ.Inc();
}
private void InPortA()
{
InPortR(A);
WZ.Value = BC.Value;
WZ.Inc();
}
private void ini()
{
WZ.Value = BC.Value;
WZ.Inc();
inx(true);
}
