Design a look-ahead carry circuit for the adder of Figure 6-10 that generates the carry C₃ to be fed to the FA of the MSB position based on the values of A₀, B₀, C₀, A₁, B₁, A₂, and B₂. In other words, derive an expression for C₃ in terms of A₀, B₀, C₀, A₁, B₁, A₂, and B₂. (Begin by writing the expression for C₁ in terms of A₀, B₀, and C₀. Then write the expression for C₂ in terms of A₁, B₁, and C₁. Substitute the expression for C₁ into the expression for C₂. Then write the expression for C₃ in terms of A_2, B₂, and C₂. Substitute the expression for C₂ into the expression for C₃. Simplify the final expression for C₃ and put it in sum-of-products form. Implement the circuit.)

Figure 6-10

Transcribed Image Text:

LOAD> C4 CLEAR> TRANSFER> CLKD FA D >CLK B₂ A₂ CLR CLEAR LOAD TRANSFER I I 4 1 T CLK D DCLK 12 FA CLR D B₂ A₂ T 1 13 S₁ CLK 1₂ FA D >CLK CLR (h) D B₂ 100 A₁ Accumulator outputs (a) 1 1 5 Sor CLK D FA D >CLK CLR Bo Ao B register -Co 4-bit adder A register