D flip-flop, S-R master-slave flip-flop, falling edge of clock, NAND

In summary, a D flip-flop is implemented using an S-R master-slave flip-flop that changes states on the falling edge of the clock. The set-up (Tsu), hold (Th), and propagation delay (Tpd) parameters for this D flip-flop can be determined by analyzing the circuit which is fabricated using NAND gates and has a propagation delay of Tpd = 1ns. To convert a master-slave S-R flip-flop into a J-K, appropriate gates can be used. The behavior of this circuit can be compared to a falling edge-triggered J-K flip-flop, which has fundamental differences such as the clock triggering edge and the output being affected by both inputs. In order to properly set up
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Homework Statement


A D flip-flop is implemented using an S-R master-slave flip-flop that changes states on the falling edge of the clock. Assume that the circuit is fabricated using NAND gates and that each gate has exactly a propagation delay Tpd = 1ns.

a) Determine the set-up (Tsu), hold (Th), and propagation delay (Tpd) parameters for this D flip-flop.

b)
*Convert a master-slave S-R flip-slop into a J-K using the appropriate gates.
*Compare the behaviour of this circuit to a falling edge-triggered J-K flip-flop. What are the fundamental differences?

Homework Equations


N/A

The Attempt at a Solution


I watched this video ( ) and, it helped me somewhat understand the basics but, I am still not too certain as to what is going on, specifically, and I'm unsure as to how I should start this problem.

I don't know what else to say but, if you need to me to say something, ask me.

Any help in solving this problem would be greatly appreciated!
 
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  • #2
Draw the logic diagram for the D-Type using NAND gates. Explore what happens when you keep the clock = 1 but D changes. The change on D will propagate around inside the latch. What happens if the clock falls while that's still happening? Will the output Q end up as the old or new value of D? If you want Q to become the new value of D how long do you need to allow for the change to propagate around inside the latch before the clock can change. That's the set up time.
 

1. What is a D flip-flop and how does it work?

A D flip-flop is a type of sequential logic circuit that stores one bit of data. It has two inputs, D (data) and CLK (clock), and two outputs, Q (current state) and Q' (complement of current state). The output Q changes to match the input D only when the clock signal transitions from high to low (falling edge). This allows for the storage of data on the rising edge of the clock.

2. What is the difference between a D flip-flop and an S-R master-slave flip-flop?

A D flip-flop and an S-R master-slave flip-flop are both types of sequential logic circuits that store one bit of data. The main difference between the two is that the S-R master-slave flip-flop has two separate stages, an S-R latch and a D latch, while the D flip-flop combines both stages into one circuit. This makes the D flip-flop faster and more efficient in terms of circuit design.

3. What is the significance of the falling edge of the clock signal?

The falling edge of the clock signal is significant in sequential logic circuits because it triggers the storage of data. In D flip-flops and other similar circuits, the data is only stored when the clock signal changes from high to low (falling edge). This allows for precise control and synchronization of data storage and manipulation.

4. How does a NAND gate function in sequential logic circuits?

A NAND gate is a type of logic gate that produces an output of 0 only when both of its inputs are 1. In sequential logic circuits, NAND gates are often used as the building blocks for flip-flops and other storage elements. They can be used to create a latch or flip-flop by connecting the output of one NAND gate to the input of another, creating a feedback loop.

5. What are the advantages of using D flip-flops and S-R master-slave flip-flops in circuit design?

D flip-flops and S-R master-slave flip-flops are commonly used in circuit design because they offer advantages such as fast operation, low power consumption, and reliability. They are also relatively simple to implement and can be cascaded to create larger storage elements. Additionally, they can be used in a variety of applications, making them versatile components in many electronic devices.

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