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Observer sskhati
Observer
6,591 Views
Registered: ‎11-24-2010

HOW TO GENERATE 125 MHz , 250 MHz CLOCK

HI,

     

        i am using sp605 board, and i need to generate a 125 MHz clock and a 250 MHz clock for my design.

        on the board there is one 27MHz crystal and a 200 mhz differential clock. 

        i have gone through the ug382 document but wasnt able to comprehend much as i am new to this field.

        seniors please suggest me how to generate the two clocks and the how to proceed to get more clarity on the topic

 

 

 

sskhati

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6 Replies
Instructor
Instructor
6,588 Views
Registered: ‎07-21-2009

Re: HOW TO GENERATE 125 MHz , 250 MHz CLOCK

Spend some quality time with the Spartan training videos, found here.  The 3rd video discusses clocking resources.

Also, use the ISE (SW tools) tutorial, UG695.  This will help you learn to use the design tools, including the Clocking Wizard.

 

-- 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.
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Observer sskhati
Observer
6,578 Views
Registered: ‎11-24-2010

Re: HOW TO GENERATE 125 MHz , 250 MHz CLOCK

hi bob,

 

i am using ise webpack edition . will i be able to use the core generator and clocking wizard tools and use those to configure my sp605 board?

is core generator a free tool?

i have sp605 board but i dont have the licence for the tools that came along with it. 

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Adventurer
Adventurer
6,570 Views
Registered: ‎02-09-2012

Re: HOW TO GENERATE 125 MHz , 250 MHz CLOCK

Webpack also includes the coregen tool, yes.

 

for "normal" frequency constellations, the CoreGen finds a soution. Sometimes you need to chain two DCMs to get your "weired" freq.

 

For a S3E, I had to use  50 ->  ( 1:2)  > 25 MHz  and then  25MHz -> (27:5) -> 135 MHz.

 

 

 

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Observer sskhati
Observer
6,568 Views
Registered: ‎11-24-2010

Re: HOW TO GENERATE 125 MHz , 250 MHz CLOCK

hi,

 

i know that coregen tool comes with the ise web pack edition but i would like know whether i would be able to use the generated core containing DCM and PLLs to configure the fpga on sp605 board without a license.

many cores generated through the tool like FFT etc require a license  .

 

it would be really helpful if somebody from  xilinx or some seniors bring clarity on the issue?

 

 

sskhati

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Instructor
Instructor
6,554 Views
Registered: ‎07-21-2009

How to quickly and easily find simple answers to your questions about ISE

i am using ise webpack edition . will i be able to use the core generator and clocking wizard tools and use those to configure my sp605 board? is core generator a free tool?

 

it would be really helpful if somebody from  xilinx or some seniors bring clarity on the issue?

 

  1. Navigate to the xilinx.com main website page:  www.xilinx.com
  2. Click on Design Tools
  3. Click on ISE Design Suite
  4. View the ISE Design Suite Comparison Table on this page

-- 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.
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Adventurer
Adventurer
6,543 Views
Registered: ‎02-09-2012

Re: HOW TO GENERATE 125 MHz , 250 MHz CLOCK and many more things ....

I have a demo VGA design running including two chained DCMs (it is even possible to generate this double DCM explicitely with the CoreGen for Spartan 3) and also FFT usage.

 

See the lower image at the "oscilloscope implementation" for a screen with FFT.

http://www.mikrocontroller.net/articles/Projekt_VGA_Core_in_VHDL

 

It totally synthesizes with the Webedition only - and for any board. Tested in e.g. S3E, S3A, S6LXT150

 

 

 

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