12.7 Counter ICs
In Sec. 12.6.5, you saw how flip-flops could be combined to make both asynchronous (ripple) and synchronous counters. In practice, using discrete flip-flops is to be avoided. Instead, use a prefabricated counter IC. These ICs cost a dollar or two and come with many additional features, like control enable inputs, parallel loading, and so on. A number of different kinds of counter ICs are available. They come in either synchronous (ripple) or asynchronous forms and are usually designed to count in binary or binary-coded decimal (BCD).
12.7.1 Asynchronous Counter (Ripple Counter) ICs
Asynchronous counters work fine for many noncritical applications, but for high-frequency applications that require precise timing, synchronous ...