Re: Counters
A counter is a time-based and a counter based application.
What I mean is that it's used to syncronize other circuits.
For example, If I want one gate to turn on after another gate, I can use a counter.
The counter starts at zero. and (usually binary) begins counting up 1,2,3...
So lets say gate 1 activated and sent output to another gate. I could set an and-gate in circuit and tie one input to count 3.
Now this circuit will not allow anything through until the counter is at three.
Counters can be used as time delays, clock circuits (for telling time) etc...
As for the size of counter (4,8,12 bits)? This depends on how high you want your counter to count.
4- bit = 0-15
8- bit = 0-255
12- bit = 0-4095
As you can see, The more bits, the higher your counter can count. It is up to the designer to see how high a count they need.
The rule of thumb for counters is that they are in powers of 2
ex. 2^x where x is any positive number.
So 2^2 = 4, 2^3 = 8, 2^4 = 16 etc...
I hope this helps somewhat.
wa