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Beginner
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What is the best way for a NIOS II to communicate with the DDR3 SDRAM on the Cyclone 10 GX dev kit?

I am currently trying to build a project where a NIOS II needs to communicate with the SDRAM on the Cyclone 10 GX Dev Kit and was wondering what the best way of doing this is.

 

I have tried connecting together the EMIF IP to the NIOS II processor within Platform Designer but they just complain about the interfaces not aligning. I have managed to get the EMIF IP to talk to a HDL module, but is it necessary to create a custom module to interface between the NIOS II and the SDRAM or is there some pre-existing IP that can connect the NIOS II and SDRAM that I am not aware of?

 

Many thanks

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Valued Contributor II
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You can use the Address Span Expander IP in Platform Designer to expand the interface and match it with the NIOS2 CPU and connect them together.

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Beginner
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The problem is that the mismatch isn't from the address span but from the datawidths themselves. The EMIF controller has a width of 320 bits, whilst the NIOS2 can only handle 32 bits.

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Retired Employee
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320? That's a strange width. I'm pretty sure you need a power of 2 or power of 2 plus bits for ECC (if you're using it).

 

Most dev kits include an example design for the memory that may include a Nios processor or you can generate an example design from the EMIF IP Parameter Editor and connect a Nios to it..

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Beginner
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EMIF interface.pngThe design is based on the example design from the EMIF IP Parameter Editor provided with the Cyclone 10 GX dev kit which comes with a width of 320 and also a burst interface, see attached image. I assume the 320 width comes because of the hardware requirements of DDR3. I can deal with the address span with the Address Span expander IP, but I cannot just hookup the NIOS to the example design because of the bursting and the difference in data width. I have tried looking for example designs for the Cyclone 10 GX with the NIOS connected to DDR3, but to no success. It's looking like I am going to need build a custom instruction module to get them to communicate.

 

 

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Employee
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Hi,

you have to use the SDRAM controller IP witch will solve all your problems.

https://www.intel.cn/content/dam/altera-www/global/zh_CN/pdfs/literature/hb/nios2/n2cpu_nii51005.pdf

https://www.youtube.com/watch?v=FjuZ3IGNur0

 

Am I answering your question?

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Beginner
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Hi,

 

I was digging on the embedded IP peripherals user guide for NIOS II and found this:

“All the IP cores described in this user guide are supported by both Intel® Quartus® Prime Pro Edition and Intel® Quartus® Prime Standard Edition except for the following cores which are only supported by Intel® Quartus® Prime Standard Edition.

  • SDRAM Controller Core”

 

So I looked at the difference between Pro and Standard and the difference is that Pro supports Statix 10, Arria 10 and Cyclone GX 10 and standard supports all the other devices. Looks like SRAM controllers for the latest gen aren’t supported yet. I think this gen has the first hard external memory interfaces so I guess it was a major overhaul. I've seen some reference to testbenches using a NIOS and SDRAM, so I guess is internally developing it. Could Intel confirm if they have something in the works?

 

In the meantime, what I am trying to do is just build a very basic, low performance SDRAM controller that only has a bust transfer of one and then connect that to the NIOS. The SDRAM half is working fine, but getting it to talk to the NIOS is proving challenging.

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