Test: Counters - GATE MCQ

The parallel outputs of a counter circuit represent the clock count. A counter counts the number of times an event takes place in accordance to the clock pulse.

Three decade counter has 30 states and a BCD counter has 10 states. So, it would require 3 BCD counters. Thus, a three decade counter will count from 0 to 29.

Ripple counters are also called asynchronous counter. In Asynchronous counters, only the first flip-flop is connected to an external clock while the rest of the flip-flops have their preceding flip-flop output as clock to them.

Counters are of 3 types, namely, (i)asynchronous/synchronous, (ii)single and multi-mode & (iii)modulus counter. These further can be subdivided into Ring Counter, Johnson Counter, Cascade Counter, Up/Down Counter and such like.

A counter circuit is usually constructed of a number of flip-flops connected in cascade. Preferably, JK Flip-flops are used to construct counters and registers.

BCD counter is also known as decade counter because both have the same number of stages and both count from 0 to 9.

Synchronous Counter is a Medium Scale Integrated (MSI). In Synchronous Counters, the clock pulse is supplied to all the flip-flops simultaneously.

Decimal counter is also known as 10 stage counter. So, it has 10 states. It is also known as Decade Counter counting from 0 to 9.

The maximum possible range of bit-count specifically in n-bit binary counter consisting of ‘n’ number of flip-flops is 0 to 2ⁿ-1. For say, there is a 2-bit counter, then it will count till 2²-1 = 3. Thus, it will count from 0 to 3.

In digital logic and computing, a counter is a device which stores (and sometimes displays) the number of times a particular event or process has occurred, often in relationship to a clock signal.