frequency of operation ???

[barath_87]

I have a positive edge trigerred flip flop that would work at a frequency of say fmax .Now I connect another similar flip flop but a negative edgetriggered one at the o/p of the first flip flop(the positive edge triggered one ) .Now what would be the operating frequency of the complete block in terms of fmax and how.
Pls clarify my doubt . Thank you in advance.

 

[lomedva]

Please check the image.
It does depend on which of the signals you are going to use as the clock. if you use the last one, then f = fmax/4, the middle one is fmax/2.

 

[amriths04]

if they are synchronous it will be 2*fmax. draw the timing diagram and check it. that is the best way to clear these doubts.

 

[ubna]

It operates with the same frequency fmax..

 

[avimit]

It would still be fmax. Simply because its the clock you are providing.
But I guess what you would like to know is may be what is the throughput i.e data output per clock cycle. Well throughput would be 2 times of what it would be if you were not using any -ive edge triggered flipflops.
Hope it helps, if not the pls elaborate what exactly you are looking for?
Kr,
Avi
http://www.vlsiip.com

 

[alok_msh]

A synchronous block working off a clock woth fmax freq will operate at fmax freq irrespective of whether we use +ve or _ve edge trigger flops in the block. we need to be careful wuth the timing of such blocks.