/* Execute Step Comments:
* The temp variables Rs,Rd,Operand8,etc registers are defined in constructor Main() method to avoid memory leaks.
* But, this also means they will also retain the same value even after ExecuteStep() is called again.
* So, for any temp variables, modify all its constituent variables then only use it.
* e.g. Do not use Operand16 by modifying just its LB or HB.
*/
private void ExecuteStep()
{
IC++;
CCC = CCC + Int32.Parse(I.Names[m[PC.DEC16].DEC8, 2]);
if (changeInte == true) //Interrupt control logic (as ei/de affects inte f/f only during next instruction)
{
if (changeInteTo == true)
{
inte = true;
}
else
{
inte = false;
}
changeInte = false;
UpdateInterrupt();
}
Opcode.DEC8 = m[PC.DEC16].DEC8;
// * DATA TRANSFER GROUP *
if (BitCombination(Opcode[7], Opcode[6]) == "01") //MOV,HLT
{
//Except Rs=Rd=M 01110110 hlt
if (BitCombination(Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "110110")
{
//Halt Rs=Rd=M 01110110 hlt
Stop();
return;
}
else
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
Set8BitRegisterValue(Rs.DEC8, Opcode[5], Opcode[4], Opcode[3]);
PC.INX();
}
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[2], Opcode[1], Opcode[0]) == "00110") //MVI Rd,8BitData
{
PC.INX();
Operand8.DEC8 = m[PC.DEC16].DEC8;
Set8BitRegisterValue(Operand8.DEC8, Opcode[5], Opcode[4], Opcode[3]);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "000001") //LXI Rp,16BitData
{
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
Set16BitRegisterValue(true, Operand16.DEC16, Opcode[5], Opcode[4]);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00111010") //LDA
{
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
PSW.HB.DEC8 = m[Operand16.DEC16].DEC8;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00110010") //STA
{
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
m[Operand16.DEC16].DEC8 = PSW.HB.DEC8;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00101010") //LHLD
{
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
HL.LB.DEC8 = m[Operand16.DEC16].DEC8;
Operand16.INX();
HL.HB.DEC8 = m[Operand16.DEC16].DEC8;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00100010") //SHLD
{
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
m[Operand16.DEC16].DEC8 = HL.LB.DEC8;
Operand16.INX();
m[Operand16.DEC16].DEC8 = HL.HB.DEC8;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00001010") //LDAX B
{
PSW.HB.DEC8 = m[BC.DEC16].DEC8;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00011010") //LDAX D
{
PSW.HB.DEC8 = m[DE.DEC16].DEC8;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11101010") //XCHG
{
Operand16.DEC16 = HL.DEC16;
HL.DEC16 = DE.DEC16;
DE.DEC16 = Operand16.DEC16;
PC.INX();
}
else if (Opcode.DEC8 == 219) //IN 8bitIOPortAddress
{
PC.INX();
PSW.HB.DEC8 = io[m[PC.DEC16].DEC8].DEC8;
PC.INX();
}
else if (Opcode.DEC8 == 211) //OUT 8bitIOPortAddress
{
PC.INX();
io[m[PC.DEC16].DEC8].DEC8 = PSW.HB.DEC8;
PC.INX();
}
// * ARITHMETIC GROUP *
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10000") //ADD Rs
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
if ((PSW.HB.GetLowerNibble() + Rs.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((PSW.HB.DEC8 + Rs.DEC8) > 255)
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Rs.DEC8 - 256);
}
else
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Rs.DEC8);
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10001") //ADC R
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
byte i;
if (PSW.LB[0] == true)
{
i = 1;
}
else
{
i = 0;
}
if ((PSW.HB.GetLowerNibble() + Rs.GetLowerNibble() + i) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((PSW.HB.DEC8 + Rs.DEC8 + i) > 255)
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Rs.DEC8 + i - 256);
}
else
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Rs.DEC8 + i);
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11000110") //ADI 8bitdata
{
PC.INX();
Operand8.DEC8 = m[PC.DEC16].DEC8;
if ((PSW.HB.GetLowerNibble() + Operand8.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((PSW.HB.DEC8 + Operand8.DEC8) > 255)
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Operand8.DEC8 - 256);
}
else
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Operand8.DEC8);
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11001110") //ACI 8bitdata
{
PC.INX();
Operand8.DEC8 = m[PC.DEC16].DEC8;
byte i;
if (PSW.LB[0] == true)
{
i = 1;
}
else
{
i = 0;
}
if ((PSW.HB.GetLowerNibble() + Operand8.GetLowerNibble() + i) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((PSW.HB.DEC8 + Operand8.DEC8 + i) > 255)
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Operand8.DEC8 + i - 256);
}
else
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Operand8.DEC8 + i);
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[2], Opcode[1], Opcode[0]) == "00100") //INR R
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[5], Opcode[4], Opcode[3]);
if (Rs.GetLowerNibble() == 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if (Rs.DEC8 == 255)
{
Rs.DEC8 = (byte)(0 + 1);
}
else
{
Rs.DEC8 = (byte)(Rs.DEC8 + 1);
}
Set8BitRegisterValue(Rs.DEC8, Opcode[5], Opcode[4], Opcode[3]);
UpdateP(Rs.DEC8);
UpdateS(Rs.DEC8);
UpdateZ(Rs.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10010") //SUB R
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
Rs.DEC8 = Rs.Get2sComplement();
//In 2's complement addition, complement both CY and AC. Here, it is done directly in if conditional
//by inverting true and false.
if ((PSW.HB.GetLowerNibble() + Rs.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((PSW.HB.DEC8 + Rs.DEC8) > 255)
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Rs.DEC8 - 256);
}
else
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Rs.DEC8);
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10011") //SBB R
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
if (PSW.LB[0] == true)
{
if (Rs.DEC8 == 255)
{
Rs.DEC8 = 0;
}
else
{
Rs.DEC8 = (byte)(Rs.DEC8 + 1);
}
}
Rs.DEC8 = Rs.Get2sComplement();
if ((PSW.HB.GetLowerNibble() + Rs.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((PSW.HB.DEC8 + Rs.DEC8) > 255)
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Rs.DEC8 - 256);
}
else
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Rs.DEC8);
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11010110") //SUI 8bitData
{
PC.INX();
Operand8.DEC8 = m[PC.DEC16].DEC8;
Operand8.DEC8 = Operand8.Get2sComplement();
if ((PSW.HB.GetLowerNibble() + Operand8.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((PSW.HB.DEC8 + Operand8.DEC8) > 255)
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Operand8.DEC8 - 256);
}
else
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Operand8.DEC8);
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11011110") //SBI 8BitDAta
{
PC.INX();
Operand8.DEC8 = m[PC.DEC16].DEC8;
if (PSW.LB[0] == true)
{
if (Operand8.DEC8 == 255)
{
Operand8.DEC8 = 0;
}
else
{
Operand8.DEC8 = (byte)(Operand8.DEC8 + 1);
}
}
Operand8.DEC8 = Operand8.Get2sComplement();
if ((PSW.HB.GetLowerNibble() + Operand8.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((PSW.HB.DEC8 + Operand8.DEC8) > 255)
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Operand8.DEC8 - 256);
}
else
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + Operand8.DEC8);
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[2], Opcode[1], Opcode[0]) == "00101") //DCR R
{
/*Rs.DEC8 = Get8BitRegisterValue(Opcode[5], Opcode[4], Opcode[3]);
*
* Rs.DEC8 = Rs.Get2sComplement();
*
* if (Rs.GetLowerNibble() == 15)
* PSW.LB[4] = true;
* else
* PSW.LB[4] = false;
*
* if (Rs.DEC8 == 255)
* {
* Rs.DEC8 = (byte)(0 + 1);
* }
* else
* {
* Rs.DEC8 = (byte)(Rs.DEC8 + 1);
* }
*
* Set8BitRegisterValue(Rs.DEC8, Opcode[5], Opcode[4], Opcode[3]);
* UpdateP(Rs.DEC8);
* UpdateS(Rs.DEC8);
* UpdateZ(Rs.DEC8);
*
* PC.INX();
* */
Rd.DEC8 = Get8BitRegisterValue(Opcode[5], Opcode[4], Opcode[3]);
Rs.DEC8 = 1; //As 1 is substracted
Rs.DEC8 = Rs.Get2sComplement();
//In 2's complement addition, complement both CY and AC. Here, it is done directly in if conditional
//by inverting true and false.
if ((Rd.GetLowerNibble() + Rs.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((Rd.DEC8 + Rs.DEC8) > 255)
{
PSW.LB[0] = false;
Rd.DEC8 = (byte)(Rd.DEC8 + Rs.DEC8 - 256);
}
else
{
PSW.LB[0] = true;
Rd.DEC8 = (byte)(Rd.DEC8 + Rs.DEC8);
}
Set8BitRegisterValue(Rd.DEC8, Opcode[5], Opcode[4], Opcode[3]);
UpdateP(Rd.DEC8);
UpdateS(Rd.DEC8);
UpdateZ(Rd.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "000011") //INX Rp
{
switch (BitCombination(Opcode[5], Opcode[4]))
{
case "00":
{
BC.INX();
break;
}
case "01":
{
DE.INX();
break;
}
case "10":
{
HL.INX();
break;
}
case "11":
{
SP.INX();
break;
}
}
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "001011") //DCX Rp
{
switch (BitCombination(Opcode[5], Opcode[4]))
{
case "00":
{
BC.DCX();
break;
}
case "01":
{
DE.DCX();
break;
}
case "10":
{
HL.DCX();
break;
}
case "11":
{
SP.DCX();
break;
}
}
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "001001") //DAD Rp,16BitData
{
Operand16.DEC16 = Get16BitRegisterValue(true, Opcode[5], Opcode[4]);
if ((HL.DEC16 + Operand16.DEC16) > 65535)
{
PSW.LB[0] = true;
HL.DEC16 = (ushort)(HL.DEC16 + Operand16.DEC16 - 65536);
}
else
{
PSW.LB[0] = false;
HL.DEC16 = (ushort)(HL.DEC16 + Operand16.DEC16);
}
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00100111") //DAA
{
if ((PSW.HB.GetLowerNibble() > 9) || (PSW.LB[4] == true))
{
//Add 6 to lower nibble
if ((PSW.HB.GetLowerNibble() + 6) > 15)
{
PSW.LB[4] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + 6 - 16); //6 is added, 16 is sub to neutralize overflow out of nibble
}
else
{
PSW.LB[4] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + 6);
}
}
else
{
PSW.LB[4] = false;
}
byte i;
if (PSW.LB[4] == true)
{
i = 1;
}
else
{
i = 0;
}
if ((PSW.HB.GetHigherNibble() > 9) || (PSW.LB[0] == true))
{
bool PreviousCY = PSW.LB[0];
//Add 6 to higher nibble
if ((PSW.HB.GetHigherNibble() + 6 + i) > 15)
{
PSW.LB[0] = true;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + (6 + i - 16) * 16); //i is carry from lower nibble, Multiply by 16 to reach uppaer nibble ( i.e. up by 4 bits 2^4)
}
else
{
PSW.LB[0] = false;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 + (6 + i) * 16);
}
if (PreviousCY) //Set CY if it was initially set
{
PSW.LB[0] = true;
}
}
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
// * LOGICAL GROUP *
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10100") //ANA R
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 & Rs.DEC8);
PSW.LB[0] = false;
PSW.LB[4] = true;
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11100110") //ANI 8bitData
{
PC.INX();
Operand8.DEC8 = m[PC.DEC16].DEC8;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 & Operand8.DEC8);
PSW.LB[0] = false;
PSW.LB[4] = true;
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10110") //ORA R
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 | Rs.DEC8);
PSW.LB[0] = false;
PSW.LB[4] = false;
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11110110") //ORI 8bitData
{
PC.INX();
Operand8.DEC8 = m[PC.DEC16].DEC8;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 | Operand8.DEC8);
PSW.LB[0] = false;
PSW.LB[4] = false;
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10101") //XRA R
{
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 ^ Rs.DEC8);
PSW.LB[0] = false;
PSW.LB[4] = false;
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11101110") //XRI 8bitData
{
PC.INX();
Operand8.DEC8 = m[PC.DEC16].DEC8;
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 ^ Operand8.DEC8);
PSW.LB[0] = false;
PSW.LB[4] = false;
UpdateP(PSW.HB.DEC8);
UpdateS(PSW.HB.DEC8);
UpdateZ(PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00101111") //CMA
{
PSW.HB.DEC8 = (byte)(~PSW.HB.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00111111") //CMC
{
PSW.LB[0] = !PSW.LB[0];
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00110111") //STC
{
PSW.LB[0] = true;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10111") //CMP R
{
Operand8.DEC8 = PSW.HB.DEC8;
Rs.DEC8 = Get8BitRegisterValue(Opcode[2], Opcode[1], Opcode[0]);
Rs.DEC8 = Rs.Get2sComplement();
if ((Operand8.GetLowerNibble() + Rs.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((Operand8.DEC8 + Rs.DEC8) > 255)
{
PSW.LB[0] = false;
Operand8.DEC8 = (byte)(Operand8.DEC8 + Rs.DEC8 - 256);
}
else
{
PSW.LB[0] = true;
Operand8.DEC8 = (byte)(Operand8.DEC8 + Rs.DEC8);
}
UpdateP(Operand8.DEC8);
UpdateS(Operand8.DEC8);
UpdateZ(Operand8.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3]) == "10111") //CPI 8bitData
{
Operand8.DEC8 = PSW.HB.DEC8;
PC.INX();
Rs.DEC8 = m[PC.DEC16].DEC8;
Rs.DEC8 = Rs.Get2sComplement();
if ((Operand8.GetLowerNibble() + Rs.GetLowerNibble()) > 15)
{
PSW.LB[4] = true;
}
else
{
PSW.LB[4] = false;
}
if ((Operand8.DEC8 + Rs.DEC8) > 255)
{
PSW.LB[0] = false;
Operand8.DEC8 = (byte)(Operand8.DEC8 + Rs.DEC8 - 256);
}
else
{
PSW.LB[0] = true;
Operand8.DEC8 = (byte)(Operand8.DEC8 + Rs.DEC8);
}
UpdateP(Operand8.DEC8);
UpdateS(Operand8.DEC8);
UpdateZ(Operand8.DEC8);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00000111") //RLC
{
bool D7 = PSW.HB[7];
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 << 1);
PSW.HB[0] = D7;
PSW.LB[0] = D7;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00001111") //RRC
{
bool D0 = PSW.HB[0];
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 >> 1);
PSW.HB[7] = D0;
PSW.LB[0] = D0;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00010111") //RAL
{
bool D7 = PSW.HB[7];
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 << 1);
PSW.HB[0] = PSW.LB[0];
PSW.LB[0] = D7;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "00011111") //RAR
{
bool D0 = PSW.HB[0];
PSW.HB.DEC8 = (byte)(PSW.HB.DEC8 >> 1);
PSW.HB[7] = PSW.LB[0];
PSW.LB[0] = D0;
PC.INX();
}
// * STACK AND MACHINE CONTROL GROUP *
else if (BitCombination(Opcode[7], Opcode[6], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "110101") //PUSH Rp
{
//FOR Push/Pop and in Branching only , IsSP = false i.e. return PC
Operand16.DEC16 = Get16BitRegisterValue(false, Opcode[5], Opcode[4]);
SP.DCX();
m[SP.DEC16].DEC8 = Operand16.HB.DEC8;
SP.DCX();
m[SP.DEC16].DEC8 = Operand16.LB.DEC8;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "110001") //POP Rp
{
Operand16.LB.DEC8 = m[SP.DEC16].DEC8;
SP.INX();
Operand16.HB.DEC8 = m[SP.DEC16].DEC8;
SP.INX();
Set16BitRegisterValue(false, Operand16.DEC16, Opcode[5], Opcode[4]);
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11111001") //SPHL
{
SP.DEC16 = HL.DEC16;
PC.INX();
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11100011") //XTHL
{
Operand16.DEC16 = HL.DEC16;
HL.LB.DEC8 = m[SP.DEC16].DEC8;
m[SP.DEC16].DEC8 = Operand16.LB.DEC8;
if (SP.DEC16 == 255) //Check for overflow
{
HL.HB.DEC8 = m[0].DEC8;
m[0].DEC8 = Operand16.HB.DEC8;
}
else
{
HL.HB.DEC8 = m[SP.DEC16 + 1].DEC8;
m[SP.DEC16 + 1].DEC8 = Operand16.HB.DEC8;
}
PC.INX();
}
else if (Opcode.DEC8 == 0) //NOP
{
PC.INX();
}
else if (Opcode.DEC8 == 251) //EI
{
changeInte = true;
changeInteTo = true;
PC.INX();
}
else if (Opcode.DEC8 == 251) //DI
{
changeInte = true;
changeInteTo = false;
PC.INX();
}
else if (Opcode.DEC8 == 32) //RIM
{
//Read sid and output to d7 bit of accumulator
if (rbSid0.IsChecked == true)
{
PC.HB[7] = false;
}
else
{
PC.HB[7] = true;
}
//No logic for interrupts pending in simulator
//Read inte
if (inte == true)
{
PC.HB[3] = true;
}
else
{
PC.HB[3] = false;
}
//Reads masks
if (interrupt[2] == true) //M7.5
{
PC.HB[2] = true;
}
else
{
PC.HB[2] = false;
}
if (interrupt[1] == true) //M6.5
{
PC.HB[1] = true;
}
else
{
PC.HB[1] = false;
}
if (interrupt[0] == true) //M5.5
{
PC.HB[0] = true;
}
else
{
PC.HB[0] = false;
}
PC.INX();
UpdateInterrupt();
}
else if (Opcode.DEC8 == 48) //SIM
{
//Set sod=1 if sde=1 else sod=0
if (PC.HB[6] == true)
{
if (PC.HB[7] == true)
{
tbSod.Text = "1";
}
else
{
tbSod.Text = "0";
}
}
if (PC.HB[4] == true) //Resets r7.5 f/f, else has no effect
{
r75 = false;
}
if (PC.HB[3] == true) //MSE
{
if (PC.HB[2] == true) //M'7.5
{
interrupt[2] = true;
}
else
{
interrupt[2] = false;
}
if (PC.HB[1] == true) //M'6.5
{
interrupt[1] = true;
}
else
{
interrupt[1] = false;
}
if (PC.HB[0] == true) //M'5.5
{
interrupt[0] = true;
}
else
{
interrupt[0] = false;
}
}
PC.INX();
UpdateInterrupt();
}
// * BRANCH GROUP *
//In branch group, take care of whether to execute PC.INX() or not at end.
else if (BitCombination(Opcode[7], Opcode[6], Opcode[5], Opcode[4], Opcode[3], Opcode[2], Opcode[1], Opcode[0]) == "11101001") //PCHL
{
PC.DEC16 = HL.DEC16;
}
else if (Opcode.DEC8 == 195) //JMP
{
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
PC.DEC16 = Operand16.DEC16;
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[2], Opcode[1], Opcode[0]) == "11010") //Conditional Jump
{
if (CheckCondition(Opcode[5], Opcode[4], Opcode[3]) == true)
{
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
PC.DEC16 = Operand16.DEC16;
}
else
{
PC.INX();
PC.INX();
PC.INX();
}
}
else if (Opcode.DEC8 == 205) //CALL
{
//Storing address to be branched in temp register Operand16
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
//Push contents of PC onto stack
SP.DCX();
m[SP.DEC16].DEC8 = PC.HB.DEC8;
SP.DCX();
m[SP.DEC16].DEC8 = PC.LB.DEC8;
//Branch
PC.DEC16 = Operand16.DEC16;
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[2], Opcode[1], Opcode[0]) == "11100") //Conditional CALL
{
if (CheckCondition(Opcode[5], Opcode[4], Opcode[3]) == true)
{
//Storing address to be branched in temp register Operand16
PC.INX();
Operand16.LB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
Operand16.HB.DEC8 = m[PC.DEC16].DEC8;
PC.INX();
//Push contents of PC onto stack
SP.DCX();
m[SP.DEC16].DEC8 = PC.HB.DEC8;
SP.DCX();
m[SP.DEC16].DEC8 = PC.LB.DEC8;
//Branch
PC.DEC16 = Operand16.DEC16;
}
else
{
PC.INX();
PC.INX();
PC.INX();
}
}
else if (Opcode.DEC8 == 201) //RET
{
//Pop content from stack to temp RegisterPair Operand16
Operand16.LB.DEC8 = m[SP.DEC16].DEC8;
SP.INX();
Operand16.HB.DEC8 = m[SP.DEC16].DEC8;
SP.INX();
//Branch
PC.DEC16 = Operand16.DEC16;
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[2], Opcode[1], Opcode[0]) == "11000") //Conditional Return
{
if (CheckCondition(Opcode[5], Opcode[4], Opcode[3]) == true)
{
Operand16.LB.DEC8 = m[SP.DEC16].DEC8;
SP.INX();
Operand16.HB.DEC8 = m[SP.DEC16].DEC8;
SP.INX();
//Branch
PC.DEC16 = Operand16.DEC16;
}
else
{
PC.INX();
}
}
else if (BitCombination(Opcode[7], Opcode[6], Opcode[2], Opcode[1], Opcode[0]) == "11111") //RST N
{
PC.INX();
//Push contents of PC onto stack
SP.DCX();
m[SP.DEC16].DEC8 = PC.HB.DEC8;
SP.DCX();
m[SP.DEC16].DEC8 = PC.LB.DEC8;
//Branch
switch (BitCombination(Opcode[5], Opcode[4], Opcode[3]))
{
case "000":
{
PC.DEC16 = 0;
break;
}
case "001":
{
PC.DEC16 = 8;
break;
}
case "010":
{
PC.DEC16 = 16;
break;
}
case "011":
{
PC.DEC16 = 24;
break;
}
case "100":
{
PC.DEC16 = 32;
break;
}
case "101":
{
PC.DEC16 = 40;
break;
}
case "110":
{
PC.DEC16 = 48;
break;
}
case "111":
{
PC.DEC16 = 56;
break;
}
}
}
else
{
//Unrecognised Instructions
PC.INX();
}
RefreshMIO(false); //Nofocus, as it will cause Stop button never to gain focus
UpdateAll();
//Rucurse in Fast Mode but in idle priority
if (rbFast.IsChecked == true)
{
bStep.IsEnabled = false;
if (IsStopped == false)
{
bStart.Dispatcher.BeginInvoke(DispatcherPriority.SystemIdle, new ExecuteStepDelegate(ExecuteStep));
}
}
}