I have questions about the flip flop based divider by 2. There are two D flip-flop.
Is one D flip-flop not enough? What is the purpose of the second flip-flop?
Thanks for your help.
One ff can store only one bit, so you have 0 and 1. When you devide 0 or 1 with two, you will get only 0. So the second ff is to have two bits representing decimal numbers from 0 to 4. So in this case when you devide 2 with 2 you will get 1... The number of ffs depends of number of bits your number can have.
If you add 10 ffs, you will be able to devide 1024decimal.
(11111111 : 2 = 0111111111)
I am Newbie in electronics.
I think my previous post was not really clear. Please let me clarify.
In fact, I would like to divide the frequency of an input signal using a flip-flop based divider by 2. I would have expected that one D flip-flop is not enough. So I do not exactly understand the purpose of the second D flip-flop....
the idea of dividing the clock by 2 goes this way........
they have 2 FF in series and they feed the clock to the FFs and the output of the 2 FFs are ANDed since there is a finite time delay between the outputs of the 2 FFs it results in clock division by 2.......
only one DFF is enough, you can connect the DFF's negative output to
its D inputs.
best regards
Meihdi said:
Hello All,
I have questions about the flip flop based divider by 2. There are two D flip-flop.
Is one D flip-flop not enough? What is the purpose of the second flip-flop?
Thanks for your help.
usually one flip flop for dividing the frequency is sufficient. two flip flops are mainly used to generate quadrature signals, that means you can not only divide the frequency but also generate two signals with 90 degrees phase offset. you can have a look at RF Microelectronics from Razavi for more details.
hope this helps.
funster said:
only one DFF is enough, you can connect the DFF's negative output to
its D inputs.
best regards
Meihdi said:
Hello All,
I have questions about the flip flop based divider by 2. There are two D flip-flop.
Is one D flip-flop not enough? What is the purpose of the second flip-flop?
Thanks for your help.
Meihdi,
If you connect the Qbar output af a D flip-flop to the D input, the output frequency will be 1/2 the input clock frequency. If this is all you need to do, then a 2nd flip flop is not necessary.
Regards,
Kral