I feel sdtupid for asking this but...

[psecody]

I have some IC's that I've been playing around with because I haven't ever used them (I used to use only discreet components) but I've got the 4013 that I'm playin around with now and I just don't understand the pins and the truth table. I understand the truth table or how it works but what I don't get is the inputs. Could some one explain the D, Clk, Rst, and Set pins? I get in theory what the reset does but I don't understand the condition at which it resets. Could someone explain what each of these pins is for and descride about them? Thanks I really appreciate it.

 

[ljcox]

D = Data, Clk = Clock

Set and Reset are active high, which means a high on one of these pins will set or reset the FF.

Is S and R are both held low, the state of D (ie. whether it is high or low) is transferred to Q when the voltage on the Clk input undergoes a positive transition, ie. goes from low to high. Q' (ie. Q bar) is complementary to Q, ie. when Q is high, Q' is low and vice versa.

There is no change to Q and Q' when the Clk input goes from high to low.

Now, if a high is applied to the Set (with R = low), the Q output is set high and Q' low.

Or if a high is appled to the Reset (with S = low), the Q output is set low and Q' high.

Set and Reset overide the clock input so it does not matter if the Clk input goes high while S or R = high.

If S & R are both high, both Q & Q' go high, but this is not normally done since there is no point in doing it.

What I have just explained is what the truth table in the data sheet specifies.

So I suggest you look at the truth table while reading my explaination and see if you can reconcile them. If not, feel free to ask more questions.

Have you done a search in this forum for "flip flop"? There have been other threads on the subject in the past.

 

[psecody]

Ok let mere phrase my question. I don't get what data and clock are, mainly clock. I know they are inputs but on all the truth tables it shows clock as a gradual rising or falling line I thought it was either on or off.

 

[Hero999]

Ideally, the clock is either on or off, in practice it does have a rise time and possibly some over and undershoot.

 

[kchriste]

Ok let mere phrase my question. I don't get what data and clock are, mainly clock. I know they are inputs but on all the truth tables it shows clock as a gradual rising or falling line I thought it was either on or off.

They show it that way because alot of flipflops (like the 4013) are "edge triggered" which means that nothing happens when the clock is high or low. The data is only entered into the flipflop when the clock changes from low to high (or high to low depending on the flipflop)....

 

[ljcox]

Ok let mere phrase my question. I don't get what data and clock are, mainly clock. I know they are inputs but on all the truth tables it shows clock as a gradual rising or falling line I thought it was either on or off.

The "gradual rising or falling line" represents the transition from low to high or high to low.

 

[psecody]

ok thanks I got it figured out and spent all day playing with it. Though I didn't get it to do quite what I was trying to do and I was using discreet components to try and make it do what I wanted to do but I never could then I started thinking wow I could do it really easily with another 4013 IC and after that it dawned on me that it had 2 IC's in that same one. So now I understand that IC thanks for the replies they really helped, I appreciate it.

*Edit - Wow I just realized how I miss spelled stupid in the thread title haha that makes me feel good about myself.

 

[ljcox]

Now you can think about the JK Flip Flop, eg. the 4027.