Why we need to have setup/hold time for a flop?

[engr]

Hi
why we need to have setup and hold times for a flop , i know that without these, flop output goes to metastable state, but why really set and hold need to maintain for a flop
Thanks

 

[TekUT]

Re: setup/hold time

Take a look at this link:

http://www.sigcon.com/Pubs/news/4_2.htm

and also:

Metastable Response in 5V logic circuits.pdf
http://focus.ti.com/lit/an/sdya006/sdya006.pdf

Bye
Pow

 

[hemant2007]

Re: setup/hold time

go thru following link

**broken link removed**

 

[ramana459]

Re: setup/hold time

setup time and hold time are useful for set the time period (Tmax) of the circuit.
If you dont know these values, how can u find out your design is working on this freq.
If your design was not satisfy the setup and hold times you will get garbage values after the simulation.
The setup and hold time values are fixed for cell to cell, you can't modify them, these are given by fab.

 

[au_sun]

Re: setup/hold time

setup time and hold times are basically is a requirement due to transistor characteristic.

 

[ljxpjpjljx]

Re: setup/hold time

because you need setup and hold time to meet your timing!