gate 2014

Question

which is faster, synchronous circuits  or asynchronous circuits  and why?

Answer 1

Asynchronous circuits  is faster than synchronous circuits . 

Synchronization means less chance of hazards but  synchronous circuit can increase the delay. So, synchronous circuits cannot have faster operation than asynchronous one ..

 In asynchronous circuits, there is no clock, and the state of the circuit changes as soon as the input changes. Since they don't have to wait for a clock pulse to begin processing inputs, asynchronous circuits can be faster than synchronous circuits .

Comments

1>how synchronization means less chance of hazards ?

2>propagation delay for the asynchronous circuit is more tha synchronous circuit then why they are faster ?

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>how synchronization means less chance of hazards ?

If transitions on two inputs arrive at almost the same time, the circuit can go into the wrong state depending on slight differences in the propagation delays of the gates. This is called a race condition or hazard situation . In synchronous circuits this problem is " less severe" because race conditions can only occur due to inputs from outside the synchronous system .

Since asynchronous circuits don't have to wait for a clock pulse to begin processing inputs, they can be faster than synchronous circuits, and their speed is theoretically limited only by the propagation delays of the logic gates.  

Reference :

 https://en.wikipedia.org/wiki/Asynchronous_circuit#Synchronous_vs_asynchronous_logic

Answer 2

• synchronous- delay  may be get  high and the operation rate is low as compare to asynchronous so "asynchronous " is fast ..!