Difference between Synchronous and Asynchronous Sequential Circuits

Computer EngineeringComputer NetworkMCA

As the name suggests both Synchronous and Asynchronous Sequential Circuits are the type of sequential circuits which uses feedback for the next output generation however on the basis of the type of this feedback both circuits can be get differentiated.

Following are the important differences between Synchronous and Asynchronous Sequential Circuits −

Sr. No.KeySynchronous Sequential CircuitsAsynchronous Sequential Circuits
1DefinitionSynchronous sequential circuits are digital sequential circuits in which the feedback to the input for next output generation is governed by clock signals.On other hand Asynchronous sequential circuits are digital sequential circuits in which the feedback to the input for next output generation is not governed by clock signals.
2Memory UnitIn Synchronous sequential circuits, the memory unit which is being get used for governance is clocked flip flop.On other hand unclocked flip flop or time delay is used as memory element in case of Asynchronous sequential circuits.
3StateThe states of Synchronous sequential circuits are always predictable and thus reliable.On other hand there are chances for the Asynchronous circuits to enter into a wrong state because of the time difference between the arrivals of inputs. This is called as race condition.
4ComplexityIt is easy to design Synchronous sequential circuitsHowever on other hand the presence of feedback among logic gates causes instability issues making the design of Asynchronous sequential circuits difficult.
5PerformanceDue to the propagation delay of clock signal in reaching all elements of the circuit the Synchronous sequential circuits are slower in its operation speedSince there is no clock signal delay, these are fast compared to the Synchronous Sequential Circuits
6ExampleSynchronous circuits are used in counters, shift registers, memory units.On other hand Asynchronous circuits are used in low power and high speed operations such as simple microprocessors, digital signal processing units and in communication systems for email applications, internet access and networking.
raja
Published on 09-Jun-2020 08:50:52
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