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  #1 (permalink)  
Old 05-08-2009, 03:38 PM
lioncat
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Default Question on using ODDR

Hello guys, I am working on a virtex 5 and trying to read out data fro
internal distributed ROM at 250MHz. Then in order to increase data rate,
choose use ODDR which is followed by OBUF. But in the MAP I have this kin
of errors at all the output of ODDR as following,

"ERROR:Pack:1569 - The dual data rate registe
QPSK_wave/LOOP_DDR_A[6].ODDR_A
failed to join an OLOGIC component as required."

I don't have any idea to solve this error. Is there someone can give m
some hint?

Another question, I have also tried to use OSERDES which i
parallel-to-serial converter before OBUF. Then the design pass the map bu
in place and route it came out the warning as following,
"Route:436 - The router has detected an unroutable situation for one o
more connections. The router will finish the rest of the design and leav
them as unrouted, The cause of this behavior is either an issue with th
placement or unroutable placement constraints."
and occured in all the output pin of OSERDES. How to solve this?

Is there any other method to increase data rate? When I reached to 500MHz
the timing problem was always with me in post route simulation.

Thank you for help!!


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Old 05-08-2009, 04:25 PM
Symon
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Default Re: Question on using ODDR

http://lmgtfy.com/?q=instantiate+odd...ite:xilinx.com

;-)


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Old 05-08-2009, 04:38 PM
lioncat
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Default Re: Question on using ODDR

>http://lmgtfy.com/?q=instantiate+odd...ite:xilinx.com
>
>;-)
>
>
>

Thank you for reply. But I have already read the library and the templat
of the ODDR. However my problem is in the map. The unit cannot be mapped.
want to figure out how to solve this situation.
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  #4 (permalink)  
Old 05-08-2009, 05:46 PM
Symon
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Default Re: Question on using ODDR


"lioncat" <[email protected]> wrote in message
news:[email protected] ...

>>

> Thank you for reply. But I have already read the library and the template
> of the ODDR. However my problem is in the map. The unit cannot be mapped.
> I
> want to figure out how to solve this situation.


So, even if you use the exact template they suggest, maybe with a really
simple experimental design, the map doesn't work? Did you also try looking
at XAPPs with DDR? What about the FDDRRSE part, did you try that?
HTH., Syms.


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  #5 (permalink)  
Old 05-11-2009, 10:54 AM
lioncat
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Default Re: Question on using ODDR

>
>"lioncat" <[email protected]> wrote in message
>news:[email protected] m...
>
>>>

>> Thank you for reply. But I have already read the library and th

template
>> of the ODDR. However my problem is in the map. The unit cannot b

mapped.
>> I
>> want to figure out how to solve this situation.

>
>So, even if you use the exact template they suggest, maybe with a reall


>simple experimental design, the map doesn't work? Did you also tr

looking
>at XAPPs with DDR? What about the FDDRRSE part, did you try that?
>HTH., Syms.
>
>
>


Thank you for reply. I have tried your suggestion to use the ODDR in
simple experimental design. And it turns out success in MAP. So I took
deep look at my older design. Then I think the problem is that in it th
ODDR is not directly following by the OBUFDS, but a flip-flop. Therefore
changed the design and it passed the MAP and Place and Route. Maybe it wil
also work with OSEREDS.

Thanks a lot!
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  #6 (permalink)  
Old 05-11-2009, 01:55 PM
lioncat
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Default Re: Question on using ODDR

Still one question

After map, place and route, I ran the post route simulation, then I hav
the error as following,

# ** Error: /X_ODDR SETUP High VIOLATION ON D1 WITH RESPECT TO C;
# Expected := 0.434 ns; Observed := 0.386 ns; At : 68993.604 ns
# Time: 68993604 ps Iteration: 2 Instance
/test_03_04_09/uut/loop_ddr_c_4_oddr_c

Does anyone have idea about solving this kind of error?
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