Question

The frequency (in Hz) of the pulse at Z in the network shown in figure below is __________.

• A. 5

Answer 1

The correct option is A 5
Form the given circuit, we deduce the following results
1. 10-bit ring counter is a Mod-10 counter. So it divides the 160 KHz input by 10, therefore
$w=\frac{160}{10}KHz=16KHz$

2. 4-bit parallel counter counts the number of states
i.e. it is Mod -16 counter
So, $x=\frac{1600}{16}Hz=1000Hz$
3. Mod. 25 ripple counter produces the frequency as it's output as
$y=\frac{1000}{25}Hz=40Hz$
4. 4-bit Johnson counter counts the $2n$states,
i.e., it is a Mod-8 counter.
Hence, $z=\frac{40}{8}=5Hz$