IO-standard

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Anonymous
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        Hi The IOstandards of the memory of the qdrll+.   
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PriteshM_61
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25 solutions authored 10 solutions authored 5 solutions authored

Hi Subashbabu,

   

 

   

Please find the attached file with this interaction. We have updated the article and will publish it on web as early as possible. We can also have a quick call to discuss the same. Please send me your contact details on prit@cypress.com

   

 

   

Thanks

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PriteshM_61
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Employee
25 solutions authored 10 solutions authored 5 solutions authored

Hi Subashbabu,

   

 

   

The I/O standard for QDRII+ :  HSTL-I inputs and variable drive HSTL-I output buffers.

   

It supports both 1.5 V and 1.8 V I/O supply

   

 

   

Thanks

Anonymous
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 Hi 

   

   As you said the input IOstandrad is HSTL_I and output IOStandard is HSTL_DCI_I(Variable) .

   

As the given formula for the resistance the 

   

input  R = RQ/3.33 , i have taken the RQ = 250 ohms then 

   

Rinput =75 ohms

   

output R = RQ/5 then

   

Routput = 50 ohms

   

The output resistance of the memory  or the input resistance of the FPGA internal. 

   

As given reference schematic design in WEB the output does not have the output resistance

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Anonymous
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QDR II+ support HSTL-I i/o standard. For outputs, the impedance can be varied.

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Anonymous
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RQ/3.3 determines the on-die termination resistance on the input pins. You can select ODT low range and have this value almost equal to 50 ohms.

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Anonymous
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 Hi 

   

  For the output resistance is RQ/5. It is correct. The output resistance are in build to the memory . In the knowledge article the output does not have any output resistance in that schematic the input is having the resistance.

   

Thanking you

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Anonymous
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 Reference Schematic Design Recommendation for QDR-DDR II/II+/Xtreme SRAMs - KBA84386

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PriteshM_61
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Employee
25 solutions authored 10 solutions authored 5 solutions authored

Hi Subashbabu,

   

 

   

Please find the attached file with this interaction. We have updated the article and will publish it on web as early as possible. We can also have a quick call to discuss the same. Please send me your contact details on prit@cypress.com

   

 

   

Thanks

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