7.2.7 Worked Examples Pipelining
We are given a CBit module shown here. This module takes corresponding bits of two unsigned binary numbers, A and B, along with two Cin bits from higher-order CBit modules. Its output bit R, is the appropriate bit of the larger among A and B. It also has two additional output bits Cout which indicate respectively if A>B or B>A in the bits considered so far. The propagation delay of each Cbit module is 4ns. The CBit module is used to create a product MAXC which is a combinational device that determines the maximum of its two 4-bit unsigned binary inputs. It is constructed using 4 CBit modules as shown here. The first question we want to consider is what are the propagation delay and throughput of this combinational circuit? The propagation delay of a combinational circuit is the propagation delay along its longest path from input to output. In this case, the longest path is through 4 CBit modules. Since each CBit module has a propagation delay of 4 ns, the propagatio...