public int PC_J()
{
int[] bus_bits = busModule.busBits;
for (int i = bus_bits.Length - 5; i >= 0; i--)
{
pcBits[i] = bus_bits[i + 4];
if (pcBits[i] == 1)
{
pcBitGameObj[i].GetComponent <Renderer>().material.SetColor("_Color", Color.green);
}
else
{
pcBitGameObj[i].GetComponent <Renderer>().material.SetColor("_Color", Color.white);
}
}
bits = externalFunc.convertIntArrayToInt(bus_bits);
return(bits);
}
public void RAM_MI()
{
int bus_bits = externalFunc.convertIntArrayToInt(busModule.busBits);
memoryAddress = bus_bits;
}
// 4-Bit Adder Logic
int arithmeticRegisterContents(int index_reg_A, int index_reg_B, bool add, bool sub)
{
int reg_A_bits_to_int = externalFunc.convertIntArrayToInt(gameObjRegs[index_reg_A].GetComponent <RegisterModule>().bits);
int reg_B_bits_to_int = externalFunc.convertIntArrayToInt(gameObjRegs[index_reg_B].GetComponent <RegisterModule>().bits);
int carry = 0;
int sum = 0;
if (add)
{
for (int i = 0; i < 8; i++)
{
bool bit_regA_i = (reg_A_bits_to_int & (1 << i)) != 0;
bool bit_regB_i = (reg_B_bits_to_int & (1 << i)) != 0;
int bit_A = bit_regA_i == true ? 1 : 0;
int bit_B = bit_regB_i == true ? 1 : 0;
int res_xor_AB = bit_A ^ bit_B;
int res_and_AB = bit_A & bit_B;
// Sum
if ((res_xor_AB ^ carry) == 1)
{
sum += 1 * (int)Math.Pow(2, i); // sum += 1 * 2^i
carry = 0;
}
if (((carry & res_xor_AB) ^ res_and_AB) == 1)
{
carry = 1;
}
}
if (carry == 1)
{
Debug.Log("Overflow Detected");
}
}
else if (sub)
{
carry = 1; // need to carry in one bit for two's compliment
for (int i = 0; i < 8; i++)
{
bool bit_regA_i = (reg_A_bits_to_int & (1 << i)) != 0;
bool bit_regB_i = (reg_B_bits_to_int & (1 << i)) != 0;
int bit_A = bit_regA_i == true ? 1 : 0;
int bit_B = bit_regB_i == true ? 0 : 1; // invert bits for 2's compliment
int res_xor_AB = bit_A ^ bit_B;
int res_and_AB = bit_A & bit_B;
// Sum
if ((res_xor_AB ^ carry) == 1)
{
sum += 1 * (int)Math.Pow(2, i); // sum += 1 * 2^i
carry = 0;
}
if (((carry & res_xor_AB) ^ res_and_AB) == 1)
{
carry = 1;
}
}
Debug.Log(sum);
if (carry == 1) // result of subtraction is positive or zero
{
Debug.Log("Result of Sub. is positive or zero");
}
else
{
Debug.Log("Value is represented in unsigned interpretation");
Debug.Log("Signed Rep:");
Debug.Log(-256 + sum);
}
}
return(sum);
}