Asynchronous Counter

By BYJU'S Exam Prep

Updated on: September 25th, 2023

The Asynchronous Counter is made of two words asynchronous and counter. The word Asynchronous refers to managing the operation timing in a computer or communications stream by delivering a pulse only when the preceding operation is done rather than sending it at regular intervals.

A counter is a device that can count any specific event based on how many times that event(s) occurs. Therefore, An Asynchronous counter can count using Asynchronous clock input. An Asynchronous counter can count 2n- 1 possible counting states. Here, we will see the Asynchronous Counter in detail along with its applications, advantages, and disadvantages, along with knowing what “Asynchronous Counter is also known as”.

Download Formulas for GATE Computer Science Engineering – Programming & Data Structures

What is an Asynchronous Counter?

Asynchronous counters have an output that is independent of the clock signal. Because the flip flops in asynchronous counters are provided with distinct clock signals, the output may be delayed. The number of logic gates required to build asynchronous counters is quite small. As a result, their design is straightforward. The asynchronous counter is also known as Ripple counters.

The number of flip-flops needed in a ripple counter is determined by the number of counter states (ex: Mod 4, Mod 2, etc.). The number of output states of a counter is referred to as its Modulus or MOD. A counter can have a maximum of 2n states, where n is the number of flip-flops utilized in the counter.

Download Formulas for GATE Computer Science Engineering – Algorithms

Asynchronous Counter Applications

Asynchronous counters, often known as divide by N counters, are used as frequency dividers. These are utilized for low-power applications and emit less noise. These are utilized in the creation of an asynchronous decade counter.

The Asynchronous counter is also included in the Ring counter and the Johnson counter. Mod N ripple counters employ asynchronous counters. For example, the ripple counters are Mod 3, Mod 4, Mod 8, Mod 14, Mod 10, etc.

Advantages of Asynchronous counter

Asynchronous counters may be simply constructed with Toggle or D-type flip-flops. Because the clock inputs of the flip-flops are not all controlled by the same clock signal, they are referred to as Asynchronous Counters.

Each output in the chain is dependent on the previous flip-flop’s output. Asynchronous counters are sometimes known as ripple-counters because the data seems to
ipple from one flip-flop’s output to the next input.

Download Formulas for GATE Computer Science Engineering – Digital Logic

Disadvantages of Asynchronous counter

An additional
e-synchronizing output flip-flop may be needed. Extra feedback circuitry is necessary to count a shortened sequence that is not equal to 2n. When a significant number of bits are counted, the propagation delay via succeeding steps may grow unacceptably long. Because of this delay, they are known as Propagation Counters.

At high clocking frequencies, counting mistakes arise. Because they use the same clock signal for all flip-flops, synchronous counters are quicker and more dependable.

Important Topics for Gate Exam
Brittle Material Capacitors in Parallel
Capacitors in Series Carnot Cycle
Cement Test Clamping Circuit
Clipping Circuit CMOS Fabrication
CMOS Converter Column Base
Our Apps Playstore
SSC and Bank
Other Exams
GradeStack Learning Pvt. Ltd.Windsor IT Park, Tower - A, 2nd Floor, Sector 125, Noida, Uttar Pradesh 201303
Home Practice Test Series Premium