crru1 by RTb FA Do 0 4x 1 MUX FA Mux FA 0 4x1 1 MUX C3 FA 04x 1MUX Figure 4.9 4-bit arithnetic circuit TABLE 4-4 Arithmetic Circuit Function Table Microoperation Add Add with carry Subtract with borrow Subtract Transfer A 1) = A + B + 1 D., A + D-A +1 10 1 Decrement A Transfer A