Stop arguing over a nonsensical post (my emphasis added);

If you write the same value to a flip flop, say a D flip flop, in between clock cycles, will the output Q oscillate or will it remain constant like a rock ?

in between clock cycles implies that the clock is not changing.
I get the same effect with a piece of wire.

 

Stop arguing over a nonsensical post (my emphasis added);

in between clock cycles implies that the clock is not changing.
I get the same effect with a piece of wire.

It is not completely nonsensical. I could understand a new person wondering if the clock input causes a floating/non-declared state as it sweeps from rail to rail. It seems nonsensical to us because we know how they work.

The problem with questions like this is that we get some moron adding his what-if scenario into it to describe how one could force an indeterminate state during transitions and suddenly jerks (pun intended) the clarity of the thread into murky waters.

The answer is, flip flops are stable and do not jump or bump or hiss during clock transition.

 

The data input is static. The clock is static.
Can the output oscillate? It is not supposed to oscillate.
Are there certain conditions when it can change state? Sure there are.
Same for any piece of electronic component.

 

The data input is static. The clock is static.
Can the output oscillate? It is not supposed to oscillate.
Are there certain conditions when it can change state? Sure there are.
Same for any piece of electronic component.

You are reading exactly what the OP wrote, not what he meant. He is a novice, cut him some slack. Look at the context.

 

You never know the context of an inquiry when coming from an inexperienced user.

The OP never stated the context fully.

Let's take this as a possible scenario:

"I connected +5V and GND to a 74HC112 J-K flipflop. I have no data or clock connected. My Q output is oscillating. What gives?"

 

You never know the context of an inquiry when coming from an inexperienced user.

The OP never stated the context fully.

Let's take this as a possible scenario:

"I connected +5V and GND to a 74HC112 J-K flipflop. I have no data or clock connected. My Q output is oscillating. What gives?"

If you bother to read the OP's posts instead of other people's posts, it is clear that he has not yet done the experiment or connected anything. Therefore, to me, it sounds more like, "I've tried op amps and transistors and I just can't get the stability I want. I've heard about this thing called a flip-flop. Are they stable once a state is defined - even as the clock continues pulsing?"

in between clock cycles, will the output Q oscillate

Indeed... Are flip flops made with latches ? Or can they be made differently ? Because as far as I know SR latches will remain constant if you apply the same input many times. So If flops are made of latches then they certainly will hold their values and not oscillate. Oscillation is such a drag

And, this whole conversation was over after post #3...

If you write the same value to a flip flop, say a D flip flop, in between clock cycles, will the output Q oscillate or will it remain constant like a rock ?

If the D input stays constant then so will the output (like a rock) at the next clock pulse.

Fantastic thank you!

 

The data input is static. The clock is static.
Can the output oscillate? It is not supposed to oscillate.
Are there certain conditions when it can change state? Sure there are.
Same for any piece of electronic component.

I didn't mean that. I wrote the post in a hurry. I should have stated it better. I certainly didn't mean the clock is not changing at all. Obviously a clock changes every cycle. What I meant was, if you change the inputs to a D flip flop in between clock cycles (edges), say it goes from 0 to 1, to 0 to 1, etc, and then it goes back to what it what before, say 0 again, then AT the clock edge, would the flop oscillate (change from 0 to 1 repeatedly) before it goes stable again ? Or even if the input does not change at all, at each clock edge, does the output of a D flip flop oscillate for a few nanoseconds before becoming stable ? And yes, assuming correct hold and setup times. Probably not, but I wanted to ask if there was a chance. If you consider the case where a flop's input oscillates and then goes back to what it was before, as not changing at all, then that's your belief. To me if the inputs go from 0 to 1 to 0 again, that's changing, except the final value is the same as the original value.

Also, if you DO change the inputs to a D flip flop before the edge, then at the edge, can it oscillate before becoming stable at the new value ? Again I don't think so because I know latches don't oscillate and in fact are used for debouncing

 

Think about this for a moment.

Suppose at the instant the clock changes state, i.e. on a rising edge-triggered clock, the clock signal goes from low to high,
at the very same time the D-input changes state from low to high

what do you thing will happen?

Suppose someone is jumping on a trampoline and you take a snapshot of the person in motion, is the person at a low position or high position (since you can only have one of two states, no in-between)?

 

Think about this for a moment.

Suppose at the instant the clock changes state, i.e. on a rising edge-triggered clock, the clock signal goes from low to high,
at the very same time the D-input changes state from low to high

what do you thing will happen?

Suppose someone is jumping on a trampoline and you take a snapshot of the person in motion, is the person at a low position or high position (since you can only have one of two states, no in-between)?

What are you talking about? I stated the values only change before the clock edge + set up and hold times. I have no idea what you're talking about with trampolins

 

Also, if you DO change the inputs to a D flip flop before the edge, then at the edge,...

This is your statement, not mine.

 

This is your statement, not mine.

Before the edge + set up and hold times.............. Nevermind it thank you

 

.............. Nevermind it thank you

Another satisfied customer. Good work @WBahn and @MrChips </sarcasm>

 

Before the edge + set up and hold times.............. Nevermind it thank you

Setup time is how long the input signal must remain stable before the clock edge goes active, and hold time is how long the input signal must remain stable after the clock edge goes active.