The figure below shows a 16-bit carry-bypass adder. The inputs are denoted as (A₁₅A₁₄…A₀) and (B₁₅B₁₄…B₀), where A₁₅ and B₁₅ are the MSBs. P_i and G_i follow the definitions in the lecture (i.e., P_i=A_i xor B_i, G_i=A_i & B_i). Outputs S_i are omitted for simplicity. Please note that independent calculations can be performed concurrently in hardware (e.g., all Pi’s and Gi’s can be calculated simultaneously).

The following figure shows the detail inside each full adder based on P and G.

 

BP= P.PP:P, AB A,B A,B A, B FA FA FA Co2 BP= PPP&P, AB AB AB A, B FARFA FA FA Cos C06 Cot BP= P&P,P10P11 AB A,B, A1B10 ALB11 FARFARFARFA Co Co.10 BP= P1:P13P14 P15 AB12 A1B13 AB4 A15B15 Coll FARFARFARFA Coll Co,13 Coll 0,15