Chapter 9 The Adder
One function that every engineer will need many times in his or her lifetime is an adder. Each particular implementation will be slightly different. In this chapter, I present a 32-bit synchronous adder. Like the other examples in the book, the idea here is to provide a very complex function that can be scaled down and stripped down to fit your particular need. This design can be stripped down for smaller bit widths and less functionality.
The schematic representation of this adder is shown in Figure 9-1. Note that there is an output called
valid. This signal is asserted when the output of the adder is valid. This is done because in our behavioral implementation, the output is valid after one clock cycle, whereas the RTL implementation ...