cancel
Showing results for 
Search instead for 
Did you mean: 
Highlighted
Explorer
Explorer
829 Views
Registered: ‎11-01-2015

What is the disparity between DIRECT_ENABLE and EXTRACT_ENABLE?

Hi All,

 

Could anyone explain the disparity between DIRECT_ENABLE and EXTRACT_ENABLE? In my view, they have the similar functionality.

 

Thanks

2 Replies
Highlighted
Moderator
Moderator
778 Views
Registered: ‎11-04-2010

Re: What is the disparity between DIRECT_ENABLE and EXTRACT_ENABLE?

Hi, @araongao2015 ,
These 2 attributes do have the similar functionality.
As I understand:
DIRECT_ENABLE is focusing on the enable signal itself(From driver).
EXTRACT_ENABLE is focusing on the register driven by the enable signal. (From loads )

Thanks
Hong
-------------------------------------------------------------------------
Don't forget to reply, kudo, and accept as solution.
-------------------------------------------------------------------------
0 Kudos
Highlighted
Scholar
Scholar
764 Views
Registered: ‎09-16-2009

Re: What is the disparity between DIRECT_ENABLE and EXTRACT_ENABLE?

Since the question has been posed - has anyone been able to get this property to work?

 

Normally, I don't really care how synthesis builds logic.  But, under certain circumstances, one wishes to force the tools hand a bit. 

 

I've tried the "direct_enable" property - and found it doesn't work at all.  I used it, as documented to try and force synthesis to use the"CE" pin of a low-level FF.  Every instance I checked however, I found synthesis building the CE via a feedback MUX on the D input.

 

Or am I misinterpreting what this property is supposed to be doing?

 

Thanks,

 

Mark

0 Kudos