Answer to Question #208394 in Electrical Engineering for Muhammad Usman

Question

Design a 4-bit truncated ripple counter using T-flipflops which can count from 0 to 8.

Answer 1

A down counter, like an up counter, may be designed to count down a truncated sequence, but an up counter can count up to any truncated sequence. A down counter counts down from the highest count value to a predetermined count value that corresponds to the last count value in the shortened sequence. When the down-counter reaches the last count value, the counter is reset to the maximum count value rather than being cleared to zero count value as in the case of an up-counter. A 3-bit down-counter is shown in the circuit, which is set to count down a truncated sequence from 111 to 011. When the counter reaches the count value 011, it is reset to 111 before being decremented to 010 on the negative clock transition.

Truth table