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Questions regarding DCFIFO>DMA>DDR2 controller

EMeti
Beginner
390 Views

1. In Qsys read from DCFIFO write to DDR2 SDRAM using DMA fails. In other words I want to write ADC samples into DDR2 SDRAM using DCFIFO+ DMA+DDR2_controller.

2. In Qsys I add another DMA to the existing block I successfully write to and read from the same DDR2 onboard SDRAM by programming the DMA but; it is slow! 64 MB/sn.

 

Ekran Alıntısı.JPG

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3 Replies
NurAida_A_Intel
Employee
125 Views

Dear EMeti,

 

I am truly sorry for the delay in response. I missed out your thread. I will try my best to help you. Please see my reply below, I need few clarification regarding the issue.

 

1. In Qsys read from DCFIFO write to DDR2 SDRAM using DMA fails. In other words I want to write ADC samples into DDR2 SDRAM using DCFIFO+ DMA+DDR2_controller.

[NAli1]: Can you try to read/write from DCFIFO + DMA + DCFIFO? Is it pass? The reason I ask because we want to know which side is causing the problem; is it from the DMA or the DDR2 controller.

 

2. In Qsys I add another DMA to the existing block I successfully write to and read from the same DDR2 onboard SDRAM by programming the DMA but; it is slow! 64 MB/sn.

[NAli1]: As I understand it, case #1 failed to perform read/write while case#2 can passed. What is the main configuration different between case #1 and #2 ?

 

Thanks

 

Regards,

NAli1

EMeti
Beginner
125 Views

Dear NAli1_Intel,

 

Many Thanks for reply,

 

  1. for the case #1 I will try DCFIFO + DMA + DCFIFO config. then will be back.
  2. in case #2 the main difference from case #1 is: the successfull (but slow) DMA operation reads data from DDR2 SDRAM to the HOST PC memory. I check it by writing to DDR2 SDRAM via PCIe_bar_1_0 and then reading the memory content via DMA. As I said it is successfull but; slower (64 MB/s read speed) than expected 500 MB/s.
NurAida_A_Intel
Employee
125 Views

Hi EMeti,

 

Good day to you.

 

Just would like to follow-up with you any finding from your side based on my previous feedback regarding case 1 ?

 

Thanks

 

Regards,

NAli1

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