wat is synchronous and Asynchronous circuits?

brAun

hi,
a simple question, can any1 explain to me what is the synchronous and Asynchronous circuits? what are their differents?

thanks,

int80h

Synchronous circuits have a clock signal, asynchronous circuits do not have a clock signal.

In a synchronous circuit, each change to a logic level happens on a clock tick. In an asyncronous circuit, logic levels change as soon as the inputs are recieved.

kplab

http://en.wikipedia.org/wiki/Asynchronous_communication

brAun

thanks for the answer