UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

cancel
Showing results for 
Search instead for 
Did you mean: 
Explorer
Explorer
4,559 Views
Registered: ‎11-11-2013

unable to choose internal input for Cascading In Series With Two DCMs

 

HI Dear,

 

I'm trying to generate DCM by Clocking Wizard for  Cascading In Series With Two DCMs.

I want to use an internal clock signal for the input to the Cascading DCMs. But the default option is external  input clock.  It appears I can not change it. Why it's disabled for internal clock input?

 

Other information:

FPGA: Spartan-3E XC3S250

Package: TQ144

ISE:  ISE 14.4

Win7

 

DCMProblem.PNG
0 Kudos
5 Replies
Explorer
Explorer
4,553 Views
Registered: ‎11-11-2013

Re: unable to choose internal input for Cascading In Series With Two DCMs

BTW, ISE is system edition. NOT webpack.
0 Kudos
Xilinx Employee
Xilinx Employee
4,546 Views
Registered: ‎07-01-2010

Re: unable to choose internal input for Cascading In Series With Two DCMs

Hi ,

 

Looking at the reference usage , it looks like the clock input for first instance should be external.

 

DCM.JPG

---------------------------------------------------------------------------------------------
Kindly note- Please mark the Answer as "Accept as solution" if information provided is helpful.

Give Kudos to a post which you think is helpful and reply oriented.
----------------------------------------------------------------------------------------
0 Kudos
Explorer
Explorer
4,544 Views
Registered: ‎11-11-2013

Re: unable to choose internal input for Cascading In Series With Two DCMs

 

:(..

No way to use internal input clock?

0 Kudos
Xilinx Employee
Xilinx Employee
4,527 Views
Registered: ‎09-20-2012

Re: unable to choose internal input for Cascading In Series With Two DCMs

Hi,

How are you generating the clock internally?

Thanks,
Deepika.
Thanks,
Deepika.
--------------------------------------------------------------------------------------------
Google your question before posting. If someone's post answers your question, mark the post as answer with "Accept as solution". If you see a particularly good and informative post, consider giving it Kudos (the star on the left)
0 Kudos
Explorer
Explorer
4,505 Views
Registered: ‎11-11-2013

Re: unable to choose internal input for Cascading In Series With Two DCMs

 

It's generated by another single DCM.

 

What I want to do is:

External clock -> single CDM ->  Cascading In Series With Two DCMs

 

Thx

0 Kudos