Posted on 09/26/2004 7:21:46 PM PDT by heye2monn
"J-K Flip-Flop. The J-K flip-flop is the most versatile of the basic flip-flops. It has the input- following character of the clocked D flip-flop but has two inputs,traditionally labeled J and K. If J and K are different then the output Q takes the value of J at the next clock edge.
Examine Structure Applications
If J and K are both low then no change occurs. If J and K are both high at the clock edge then the output will toggle from one state to the other. It can perform the functions of the set/reset flip-flop and has the advantage that there are no ambiguous states. It can also act as a T flip-flop to accomplish toggling action if J and K are tied together. This toggle application finds extensive use in binary counters."
Source: Georgia State University physics website http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/jkflipflop.html
I don't even understand this, but it was funny nonetheless!
Kerry was an AND gate before he was a NAND gate.
Don't remind me. That computer hardware design class was a major pain.. flip flops, multiplexers, etc.. ack!
Electrical Engineer BTTT
| The JK Flip-Flop |
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To prevent any possibility of a "race" condition occurring when both the S and R inputs are at logic 1 when the CLK input falls from logic 1 to logic 0, we must somehow prevent one of those inputs from having an effect on the master latch in the circuit. At the same time, we still want the flip-flop to be able to change state on each falling edge of the CLK input, if the input logic signals call for this. Therefore, the S or R input to be disabled depends on the current state of the slave latch outputs.
If the Q output is a logic 1 (the flip-flop is in the "Set" state), the S input can't make it any more set than it already is. Therefore, we can disable the S input without disabling the flip-flop under these conditions. In the same way, if the Q output is logic 0 (the flip-flop is Reset), the R input can be disabled without causing any harm. If we can accomplish this without too much trouble, we will have solved the problem of the "race" condition.
The circuit below shows the solution. To the RS flip-flop we have added two new connections from the Q and Q' outputs back to the original input gates. Remember that a NAND gate may have any number of inputs, so this causes no trouble. To show that we have done this, we change the designations of the logic inputs and of the flip-flop itself. The inputs are now designated J (instead of S) and K (instead of R). The entire circuit is known as a JK flip-flop.
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In most ways, the JK flip-flop behaves just like the RS flip-flop. The Q and Q' outputs will only change state on the falling edge of the CLK signal, and the J and K inputs will control the future output state pretty much as before. However, there are some important differences.
Since one of the two logic inputs is always disabled according to the output state of the overall flip-flop, the master latch cannot change state back and forth while the CLK input is at logic 1. Instead, the enabled input can change the state of the master latch once, after which this latch will not change again. This was not true of the RS flip-flop.
If both the J and K inputs are held at logic 1 and the CLK signal continues to change, the Q and Q' outputs will simply change state with each falling edge of the CLK signal. (The master latch circuit will change state with each rising edge of CLK.) We can use this characteristic to advantage in a number of ways. A flip-flop built specifically to operate this way is typically designated as a T (for Toggle) flip-flop. The lone T input is in fact the CLK input for other types of flip-flops.
The JK flip-flop must be edge triggered in this manner. Any level-triggered JK latch circuit will oscillate rapidly if all three inputs are held at logic 1. This is not very useful. For the same reason, the T flip-flop must also be edge triggered. For both types, this is the only way to ensure that the flip-flop will change state only once on any given clock pulse.
Because the behavior of the JK flip-flop is completely predictable under all conditions, this is the preferred type of flip-flop for most logic circuit designs. The RS flip-flop is only used in applications where it can be guaranteed that both R and S cannot be logic 1 at the same time.
At the same time, there are some additional useful configurations of both latches and flip-flops. In the next pages, we will look first at the major configurations and note their properties. Then we will see how multiple flip-flops or latches can be combined to perform useful functions and operations.
LOL! I have an electronics background, and I never made this connection. Somebody should make aJacques Fraud Kerry logic diagram and truth table though. It would have to have some J/K FF's and at least one Exclusive AND/OR gate.
Unfortunately, all motherboards based on this gate are too elongated to fit cases of any standard form factor. Furthermore, the only language supported is COBOL.
Right now he's campaigning as an OR gate. Pretty soon he'll pretend to be a NOT gate.
how many Mega-FLOPS is jean phouqin keri up to now days??? he's approaching perpetual motion
Ah, but we not only have a J-K flip flop, we have a flip flop showing extreme metastability. After November 3, expect a major latchup condition as well. TARAYZA SETUP JK, then his finances will be on HOLD.
TECHNO-GEEK ALERT
Ah, but we not only have a J-K flip flop, we have a flip flop showing extreme metastability. After November 3, expect a major latchup condition as well. TARAYZA SETUP JK, then his finances will be on HOLD.
TECHNO-GEEK ALERT
I'm gonna name the firing pins on my derringer "J" & "K". They switch each time the hammer is pulled back.
And sinse when did we need scientific proof? ;^)
Very dense text detailing the the technical aspects of the JK Flip-Flop ... throw in many very subtle text inserts drawing analogies to John Kerrey.
Print on four color glossy paper
Distribute to engineers and engineering students
Just a thought
Can you guys make a diagram of how Kerry changes his mind to whatever he thinks most people want to hear at the time and place he runs his mouth?
This is where the J-K Flip-Flop structure fails in its application to Senator Kerry. Kerry uses flip-flops in a deliberate attempt at being ambiguous. It's all about the nuance, donchaknow.
I hated that class :(
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