# D Flip-Flop

#### battery

Joined Jan 28, 2009
4
Just wanted check if i understand correctly -

Here is the DFlip FLop

In the start all triggers have info of hex A (base 16) (meaning 1 0 1 0).
the question - 1) what info will be in these triggers after 1. , 2. , 3. , and 4. impulse.

As i understand this scheme makes a loop -
after first impulse there will be - 0 1 0 1
after second - 1 0 1 0
third - 0 1 0 1
and fourth - 1 0 1 0

Am i right? Or have i understood this completely wrong.

#### mik3

Joined Feb 4, 2008
4,846
Is the input of the second flip flop connected to the Q' of the first flip flop? Or it is just a mistake and it should be connected to Q?

#### battery

Joined Jan 28, 2009
4
Eh, there is no mistake, for some reason i didnt notice that.

So, its not as easy as i thought. So all the 0s and 1s are inverted when they go into the first flipflop ?

#### mik3

Joined Feb 4, 2008
4,846
So, its not as easy as i thought. So all the 0s and 1s are inverted when they go into the first flipflop ?
Yes, at each impulse Q3=Q0, Q2=Q0', Q1=Q2 and Q0=Q1.

#### battery

Joined Jan 28, 2009
4
i hope that this is correct now -
impulses
1) 1101
2) 0011
3) 1110
4) 0101

#### mik3

Joined Feb 4, 2008
4,846
I find

1010
0101
1010
0101

#### battery

Joined Jan 28, 2009
4
Interesting, it looks like something i wrote in my first try.

So by giving the first impulse the numbers dont switch ?

#### mik3

Joined Feb 4, 2008
4,846
Interesting, it looks like something i wrote in my first try.

So by giving the first impulse the numbers don`t switch ?
They change!!

#### Cabwood

Joined Feb 8, 2009
20
After each pulse:
Q3 becomes whatever Q0 was before the pulse,
Q2 becomes the inverse of whatever Q3 was before the pulse,
Q1 becomes whatever Q2 was before the pulse and
Q0 becomes whatever Q1 was before the pulse.

This gives me:
at start: 1010
after pulse 1) 0001
after pulse 2) 1100
after pulse 3) 0010
after pulse 4) 0101