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Cyclone 10 GX EMIF PLL clock input

Altera_Forum
Honored Contributor II
1,023 Views

After compiling a EMIF for Cyclone 10 GX, I noticed that it insists on using an external differential clock. Attempts at routing internal PLL output to pll_ref_clk input results in error. Does that mean I have to use an external LVDS oscillator, or loop a differential PLL output back to this?

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2 Replies
Altera_Forum
Honored Contributor II
173 Views

Hi, 

 

 

--- Quote Start ---  

After compiling a EMIF for Cyclone 10 GX, I noticed that it insists on using an external differential clock 

--- Quote End ---  

 

• This is user configurable option in C10 EMIF IP under PLL refclk section. 

• Set in EMIF IP thenuse the IO standard that being set in EMIF IP. 

 

--- Quote Start ---  

Attempts at routing internal PLL output to pll_ref_clk input results in error 

--- Quote End ---  

 

• Yes, this is expected. C10 EMIF PLL refclk need to come externally from board.  

 

Best Regards, 

Anand Raj Shankar 

(This message was posted on behalf of Intel Corporation) 

 

FHint
New Contributor I
173 Views

Hello,

is this also applicable for Arria 10devices?

I have found a source that states that in Quartus II 14.1 and earlier, this was also not possible for Arria 10 FPGA, but I have the same problem with Quartus 17.1.

Why is it not possible to generate the EMIF ref clk with a PLL? The *_readme.txt file says, that the ref clk is optional.

Best regards

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