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burst read and write DDR2 using altmemphy

XQSHEN
Novice
194 Views

1) Need forum admin to help, I can not post any reply on below topic even use different browser.

2) answer to this topic:

    I set memory burst length = 8, and use half rate.

   Can I set local_size = 4, 8, 16 or even higher?

 

 

XQSHEN_0-1652270982361.png

 

Re:burst read and write DDR2 using altmemphy - Intel Communities

 

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5 Replies
AdzimZM_Intel
Employee
173 Views

I think you should use local_size = 2.



XIAOQ
Beginner
166 Views

But why?

In user guide, the max = 64;

when generate the ddr ip instance, local maxinum burstcount already set = 64.

 

XIAOQ_0-1652356517888.png

 

AdzimZM_Intel
Employee
123 Views

Hello,


I hope you are doing well.


The DDR IP instance will be reflected by the IP setting.

You have set the Local Maximum Burst Count = 64.

Then the local_size width will be 6.


But the memory burst length is set to 8 beats and you are running the controller with a half rate.

So your local_size should be 2.




XIAOQ
Beginner
110 Views

Thanks! The memory burst length can only be set 8 or 4. I am not sure what's the relation of memory burst length and local maxinum burst count? why can not set higher burst local_size?

AdzimZM_Intel
Employee
101 Views

I don't have the exact reason on why you cannot set a higher local_size but I think it's the limitation on the controller side.

So you have to follow the document for your configuration.


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