You
now have the tools to design and build these new systems that will shape
our future. With your newfound power comes profound responsibility.
We hope that you will use it, not just for fun and riches, but also for
the benefit of humanity. (查看原文)
a D flip-flop copies D to Q on the rising edge of the clock, and remembers its state at all other times.
Asynchronous design in theory is more general than synchronous design, because the timing of the system is not limited by clocked registers. Just as analog circuits are more general than digital circuits because analog circuits can use any voltage, asynchronous circuits are more general than synchronous circuits because they can use any kind of feedback. However, synchronous circuits have proved to be easier to design and use than asynchronous circuits, just as digital are easier than analog circuits. Despite decades of research on asynchronous circuits, virtually all digital systems are essentially synchronous.
Of course, asynchronous circuits are occasionally necessary when communica... (查看原文)
Designing complex FSMs is often easier if they can be broken down into multiple interacting simpler state machines such that the output of some machines is the input of others. This application of hierarchy and modularity is called factoring of state machines. (查看原文)
