- Data selection
When we are using these components, which are big (bigger than flip-flop) there is less flexibility.
However, using these components provide a quality assurance, where as when we are building with basic components all depend on the ability of the creator.
There are three kinds of counters
- Up Counters [counting from 0 to MAX again 0 to MAX]
- Down counters [counting from MAX to 0 again MAX to 0]
- Up-Down counters [counting 0 to MAX to 0 to MAX …]
These counters again divided in to two categories
With the propagation delay output, do not change at once, as a example
0011 to 0100 happens in three steps
0011 -> 0010 -> 0000 -> 0100 two highlighted parts are not needed here. With these intermediate steps, we cannot use a-sync counters for high-speed operations (have to use sync). Nevertheless, these a-sync ones are easy to build.
Counters as frequency dividers
Data selection function
We can use a multiplexer with a counter to make a programmable frequency divider.