My initial problem was: Return 1 if the number of logic 1's in a 7 bit number is multiple of 3.
Thanks to some older threads I managed to come up with a way to do it.
But now I not sure if I could simplify the circuit


In x[7];
Out fxe;
FullAdder(a=x[0], b=x[1], c=x[2], sum=sum0, car=car0);
FullAdder(a=x[3], b=x[4], c=x[5], sum=sum1, car=car1);
FullAdder(a=sum0, b=sum1, c=x[6], sum=sum2, car=car2);
FullAdder(a=car0, b=car1, c=car2, sum=sum3, car=car3);
Xor(a=sum2, b=car3, out=q0);
And(a=q0, b=sum3, out=fxe);

 

Step 1.
Truth table.

Step 2.
Karnaugh Map. (K-map)

That is how normal people do it.

 

Step 1.
Truth table.

Step 2.
Karnaugh Map. (K-map)

That is how normal people do it.

Asked my teacher if I should do that and she pulled a funny face... I guess I need a new teacher