Digital Building Blocks

Up to this point, we have examined the design of combinational and sequential circuits using Boolean equations, schematics, and HDLs. This chapter introduces more elaborate combinational and sequential building blocks used in digital systems. These blocks include arithmetic circuits, couters, shift registers, memory arrays, and logic arrays. The building blocks are hierarchically assembled from simpler components such as logic gates, multiplexers, and decoders. Each buliding block has a well-defined interface and can be treated as a black box when the underlying implementation is unimportant. The regular structure of each building block is easily extended to different sizes. Later, we use many of these building blocks to build a microprocessor.