DFT query about netlist that has flops with clock enable pin

Status
Not open for further replies.
A

anssprasad

Member level 5
Joined
Jun 29, 2007
Messages
82
Helped
12
Reputation
24
Reaction score
3
Trophy points
1,288
Activity points
1,725
Hi,

If in my netlist I have flops with clock enable pin, will the netlist be considere as one which has gated clocks.

Thanks
Prasad
 

Re: DFT query

No, the netlist will not be considered as the one which has 'gated clocks' because the enable pin controls the D input inside the FF, and not the clock.
kr,
Avi
 

    A

    anssprasad

    Points: 2
    Helpful Answer Positive Rating
Re: DFT query

avimit said:
No, the netlist will not be considered as the one which has 'gated clocks' because the enable pin controls the D input inside the FF, and not the clock.
kr,
Avi
Click to expand...

Hi,

But I am using a lowpower library which might actually gate the clock input internally and not the data input using the enable.

Thanks
Prasad.
 

Re: DFT query

Well, in that case you will need to see the library spec then. I will still say that the lib vendor will not play with the clock, but to be sure, you will have to look into the lib spec. You can also have a look into the .lib file and see what are the pin functions there. Or looking at timing arcs in the .lib file may give you a clue whats going on insed the cell.
kr,
Avi
 

    A

    anssprasad

    Points: 2
    Helpful Answer Positive Rating
Re: DFT query

I have finally found what the issue was but could not trace to its origin. The pin connections of the flops with enable in my design were interchaged as follows:
CP --> E
E -- > D
D --> CP

When I realigned them in the netlist manually I could get the lec pass on the pre and post scan netlists.
 

Re: DFT query

we cant conform with that our design has gated clock. every flop has clock enable pin . gated clock is use to enable particular logic ( group of flip flops)
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…