why we need clock transtion(edge triggering) for flip-flop

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venkatesankalidass

Joined: 14 Jun 2007
Posts: 30
Helped: 1

19 Dec 2007 11:20 why we always apply trigger to flip flops

hello guys ,
why we need clock edge transtion ( either fall or rise ) for design of flip-flop

lordsathish

Joined: 11 Feb 2006
Posts: 268
Helped: 28
Location: Asia

19 Dec 2007 11:51 triggering of flip flop

sequential circuits need to synchronous... sine async ckt's have quite a number of problems like rece conditions sync ckts are preffered over them... for this synchronous operation edge-triggering is used...

deepu_s_s

Joined: 24 Mar 2007
Posts: 329
Helped: 13

19 Dec 2007 15:44 triggering of flip-flop

this is the basic difference between a flip flop and a latch.

latches are level sensitive and flip flops are edge sensitive.

This makes the contents to be stable for entire clock pulse in flip flops

Corect me if i am wrong

ericyuan

Joined: 08 Mar 2006
Posts: 37
Helped: 1

20 Dec 2007 5:26 triggering of flip-flops

synchronous at the same time ,all the flip-flop will be triged

Scott_st

Joined: 30 Dec 2007
Posts: 2
Helped: 1

30 Dec 2007 9:17 why we need clocks?

hi,l have used cadence tool,but used synopsys. l will try

kanagavel_docs

Joined: 18 Aug 2007
Posts: 40
Helped: 7

31 Dec 2007 4:59 whats the need of clock pulse in flip-flop

Hi,

If we are not using the edges, whenever the input value changes output also change accrdingly. Because of this we will get erroneous values before settling in actual value. It will make unnecessary switching and power loss. So we are narrowing the sampling window and allowing the input stable. That's why we are using edges.

Regards,
Kanags

haveidea

Joined: 24 Aug 2006
Posts: 4
Helped: 1

02 Jan 2008 2:20 triggering flip flop

First we need some cell to keep data. That means we need more than combinabtion logic.
I think use edge maybe the only way to capture data, even for latch.

santuvlsi

Joined: 19 Aug 2007
Posts: 71
Helped: 3

02 Jan 2008 7:06 triggering of of flipflop

Dear dude,

To store data we must edge trigger, either on positive edge or neative.

so only it will be understandable what data has to stored during that particular edge. mainly to synchronous data and clock to get data stored

if it level senstive it just passes the data from i/p to o/p till it reamins high.

Santu

nemolee

Joined: 28 Dec 2004
Posts: 148
Helped: 2

02 Jan 2008 11:53 why we need clocks

If we don't use DFF to latch data, we can't know the data process time.
In out application, we always do some math calculation or timing control.
If we don't use timing aspect in our design, it is always problem to real result.