Question

Draw the circuit of an asynchronous counter that converts seconds into minutes. Use positive edge triggered jk ffs. You need to show the following:

Number of FFs used and Mod-number of the counter

Label of all necessary jnputs (with their status) and outputs.

Label the overall input and overall output

Necessary circuitry.

Answer 1

we know that for every 60 seconds we get a minute:

hence we will need a counter which counts to 59 and when it reaches 60 it resets and gives an output of 1. giving us a minute output.

in order to count till 59 we will need (represent 59 in binary 111011) 6 flip flops

since the counter needs to be async. the output of the fist flip flop should be connected to the clock of the second.

hence in order to count up we will need to connect Q bar of the stage N counter to stage N+1 clock hence creating an up counter.

resetting cito reset circuit at 59 and giving a minute output

the circuit is shown below: