FA Do 0 4x MUX TA Di 4x MUX FA 0 4x1 MUX FA 04x 1 MUX Figure 4.9 4-bit arithmetic circuit TABLE 4-4 Arithnetic Circuit Function Table Input Output Microoperation Add Add with carry Subtract with borrow Subtract Transfer A Increment A Decrement A Transfer A 0 01 D=A D=A+1 DA-1 D=A