We can connect full adder with controlled inverter with some modification to add or subtract binary numbers. The carry out from each full adder is the carry in to the next full adder. The numbers being processed are A7.........Ao and B7......Bo and the output is S7.......So with 8-bits, the final carry is discarded and with 16-bits, the final carry is the carry into the addition of the upper bytes.

During the addition, the sub signal is kept in the low state. Hence the binary number B7........Bo passes through the controlled inverter with no change. The full adder than perform the correct output sum.

Addition

During the addition, the SUB signal is kept in the low state. Hence the binary number B7......Bo passes through the controlled. Inverter with no change. The full adder then perform the correct output sum.

Subtraction:

During the subtraction, the SUB signal is kept in high state. So controlled inverter produces the 1's complement of B7..........Bo. Further as SUB is the carry in to the first full adder, data is processed as,

Explore

posts on Naya and its networks

Collections