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DDR3 min/max/middle allowed frequencies

Altera_Forum
Honored Contributor II
‎12-03-2015 11:32 AM
3,091 Views

Hello,  

As for the DDR3 clock frequency, it's currently set to 533Mhz (max allowed freq). I know that the minimal supported frequency is 300MHz.  

So, can I set any frequency between 300MHz and 530Mhz? 

Why does the minimum frequency requirement exist at all?  

I'm working with ArriaV SX and the on-board DDR3 memory is Micron MT41K256M16HA-125IT.  

Thank you!
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Altera_Forum
Honored Contributor II
‎12-03-2015 12:34 PM
2,285 Views

i believe is that that allow some margin for some clock variation due to PCB design. It is the best you configured to a frequency at the middle, as due to temperature constraint, the frequency might be vary....

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Altera_Forum
Honored Contributor II
‎12-07-2015 01:34 PM
2,285 Views

 

--- Quote Start ---  

So, can I set any frequency between 300MHz and 530Mhz? 

--- Quote End ---  

Providing your chosen DDR3 memory devices supports your selection, yes. 

 

 

--- Quote Start ---  

Why does the minimum frequency requirement exist at all? 

--- Quote End ---  

The DDR3 memory's DLL will have a minimum operating frequency, below which it won't lock. 

 

Cheers, 

Alex
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