asynchronous synchronous flip-flops

Thread Starter


Joined Apr 28, 2004
I need help to the following question. I'm studying for an exam and the book says that flip-flops are actually asynchronous elements (As they are triggered with the change of the input (but not at clock pulse)). Then there is picture of a asynchronous RS flip-flop (with R=1,S=1 being forbbiden combination) made out of two NOR or NAND elements. Then the author of the book makes a synchronized RS flip-flop by adding two AND elements and the introduction of the clock. This now is a synchronized/synchronous RS flip-flop.

Up to here I understand. The author of the book is also my proffesor and I have an oral exam, where he asked somebody the next question: How to make asynchronous synchronized RS flip-flop? The clock and the synchronized part must stay in, you just have to add something new? How can I do this, and why do we do this?

How can we make a asynchronous master-slave D flip-flop (This is also a popular question)?