Don't have a Xilinx account yet?

  • Choose to receive important news and product information
  • Gain access to special content
  • Personalize your web experience on Xilinx.com

Create Account

Username

Password

Forgot your password?
XClose Panel
Xilinx Home
Reply
Visitor
abie_anaton
Posts: 10
Registered: ‎08-05-2011
0

PLL clocking output in ChipScope is missing

I am developing a DVI-controller that transmits a pre-defined pixels data packets (1 red line, 1 green line and 1 blue line, respectively) to an HDMI device.

 

I am working with SPARTAN  6 FPGA BOARD called ATLYS (Digilent Inc.).

 

My question is as follows:

 

1 - I am using a PLL primitive to generate the necessary clocks to drive the DVI encoder module.

      I synthesized the project and checked the PLL's clock outputs using the ChipScope.

     The primary output of the PLL (CLOKOUT0) was configured to drive a 100MHz clock (identical to the external clock

     that I am using in the board). 

     Unfortunately, I don't see this clock in the ChipScope.

 

    The ChipScope task configuration is as follows:

 

   -  TRIGGER LINE : board's master clock - 100MHz

   -  PLL LOCKED LINE

   -  PLL CLOKCOUT0 port  (100MHz) - non-buffered, connected directly to a BUFPLL primitive (PLLIN port)

   -  PLL CLOKCOUT1 port  (20MHz) - buffered with BUFG

   -  PLL CLOKCOUT2 port  (10MHz) - buffered with BUFG

 

 out of the above configured signals, I see all of them except the CLOCKOUT0 LINE.

 

 Can someone advise me what am I doing wrong here?

 

 Thanks,

 

 Abie Anaton

 

 

Expert Contributor
eteam00
Posts: 8,355
Registered: ‎07-21-2009

Re: PLL clocking output in ChipScope is missing

[ Edited ]

Because the signal you are probing is the same frequency as the trigger, and is (more or less) a constant phase relationship to the trigger, the captured state of the signal will be a constant.

 

It's very similar to sampling a signal with a register while using the same signal to clock the register.  The register output isn't likely to be very interesting.

 

-- Bob Elkind

SIGNATURE:
README for newbies is here: http://forums.xilinx.com/t5/New-Users-Forum/README-first-Help-for-new-users/td-p/219369

Summary:
1. Read the manual or user guide. Have you read the manual? Can you find the manual?
2. Search the forums (and search the web) for similar topics.
3. Do not post the same question on multiple forums.
4. Do not post a new topic or question on someone else's thread, start a new thread!
5. Students: Copying code is not the same as learning to design.
6 "It does not work" is not a question which can be answered. Provide useful details (with webpage, datasheet links, please).
7. You are not charged extra fees for comments in your code.
8. I am not paid for forum posts. If I write a good post, then I have been good for nothing.
Visitor
abie_anaton
Posts: 10
Registered: ‎08-05-2011
0

Re: PLL clocking output in ChipScope is missing

Ok.

 

In this case, given that I would like to probe the CLOCKOUT0 port signal, how would you suggest me to do that?

 

Regards,

Abie

Expert Contributor
eteam00
Posts: 8,355
Registered: ‎07-21-2009
0

Re: PLL clocking output in ChipScope is missing

[ Edited ]

If you want to confirm that the 100MHz CLOCKOUT0 port clock signal is running, and your sampling clock is isochronous and phase-aligned with this 100MHz clock signal -- add a divide-by-2 to your design, and probe this register.

 

I'm not a chipscope wizard (wish I had a license), this is simply a straightforward workaround suggestion.

 

-- Bob Elkind

SIGNATURE:
README for newbies is here: http://forums.xilinx.com/t5/New-Users-Forum/README-first-Help-for-new-users/td-p/219369

Summary:
1. Read the manual or user guide. Have you read the manual? Can you find the manual?
2. Search the forums (and search the web) for similar topics.
3. Do not post the same question on multiple forums.
4. Do not post a new topic or question on someone else's thread, start a new thread!
5. Students: Copying code is not the same as learning to design.
6 "It does not work" is not a question which can be answered. Provide useful details (with webpage, datasheet links, please).
7. You are not charged extra fees for comments in your code.
8. I am not paid for forum posts. If I write a good post, then I have been good for nothing.
Visitor
abie_anaton
Posts: 10
Registered: ‎08-05-2011
0

Re: PLL clocking output in ChipScope is missing

Thanks, Bob - I'll check it.

Abe

Expert Contributor
joelby
Posts: 1,094
Registered: ‎10-05-2010

Re: PLL clocking output in ChipScope is missing

Alternatively, you could always send the 100 MHz signal out to a pin and probe that with an oscilloscope.
Expert Contributor
bassman59
Posts: 6,227
Registered: ‎02-25-2008
0

Re: PLL clocking output in ChipScope is missing


abie_anaton wrote:

Ok.

 

In this case, given that I would like to probe the CLOCKOUT0 port signal, how would you suggest me to do that?

 

Regards,

Abie


Do what we did back in the old days before Chipscope -- bring the signal out to a pin.


----------------------------------------------------------------
Yes, I do this for a living.
Visitor
abie_anaton
Posts: 10
Registered: ‎08-05-2011
0

Re: PLL clocking output in ChipScope is missing

My question has nothing to do with homework or anything like that!

 

Furthermore, nobody urged you to answer, so I don't see what is the problem here.

 

Expert Contributor
joelby
Posts: 1,094
Registered: ‎10-05-2010
0

Re: PLL clocking output in ChipScope is missing

Was your comment directed at anyone in particular? None of the replies in the thread appear to me to be inflammatory or imply that your question was a homework problem.

 

I'm a native English speaker from a small, insignificant nation that is often prone to dry, sarcastic wit so I would know if anyone had meant to insult you and can assure you that no offense was intended here.

Expert Contributor
eteam00
Posts: 8,355
Registered: ‎07-21-2009
0

forum post "signature" text

[ Edited ]

Please ignore bassman's "signature" text appended automatically to the end of each of his posts.  It is not directed to you.

 

Bassman is a very generous participant in these forums.  He -- and others -- attract direct private messages asking for help on projects or design problems.  Often these appeals for help are from students who are not properly prepared for their lab or homework assignment.  Bassman's "signature" is directed to these students.

 

Notice the lengthy list of 'advice' items which appears at the end of my posts.  This is my "signature" text, representing a mini-FAQ for new forum readers.

 

These examples of signature text are not intended for personal insult.

 

-- Bob Elkind

SIGNATURE:
README for newbies is here: http://forums.xilinx.com/t5/New-Users-Forum/README-first-Help-for-new-users/td-p/219369

Summary:
1. Read the manual or user guide. Have you read the manual? Can you find the manual?
2. Search the forums (and search the web) for similar topics.
3. Do not post the same question on multiple forums.
4. Do not post a new topic or question on someone else's thread, start a new thread!
5. Students: Copying code is not the same as learning to design.
6 "It does not work" is not a question which can be answered. Provide useful details (with webpage, datasheet links, please).
7. You are not charged extra fees for comments in your code.
8. I am not paid for forum posts. If I write a good post, then I have been good for nothing.