Synchronous and asynchronous logic logical distinction
synchronization logic is a causal relationship between a fixed clock. Asynchronous logic between the clock is no causal relationship between the fixed
synchronous and asynchronous circuits distinction
synchronous clock source circuit has unity, through PLL frequency-divided clock driver modules, because a single clock source is driven, or synchronous circuit .
Asynchronous clock source circuit is not uniform
Asynchronous circuit design of the circuit is simple, low cost hardware;
Synchronous circuit design circuit consume more hardware resources, greatly improving performance while its easy static timing analysis. Using essentially synchronous LSI design methods;