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Can A10 PCIE BAR{2] access memory size be increased to 1GB (to access FPGA DDR4 1GB memory)

JET60200
New Contributor I
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hello,

we are testing A10 PCIE FPGA example & PCIE Linux driver ( follow link : https://fpgacloud.intel.com/devstore/platform/18.0.0/Pro/arria-10-pcie-gen3-x8-dma/).  After building FPGA example and run test on Linux PC, we found dmesg shows:

"

[  129.056373] Altera DMA: altera_dma_init(), Nov  6 2020 02:45:14 
[  129.056391] Altera DMA 0000:01:00.0: enabling device (0000 -> 0002)
[  129.056436] Altera DMA 0000:01:00.0: pci_enable_device() successful
[  129.056455] Altera DMA 0000:01:00.0: irq 39 for MSI/MSI-X
[  129.056461] Altera DMA 0000:01:00.0: pci_enable_msi() successful
[  129.056463] Altera DMA 0000:01:00.0: using a 64-bit irq mask
[  129.056464] Altera DMA 0000:01:00.0: irq pin: 1
[  129.056465] Altera DMA 0000:01:00.0: irq line: 11
[  129.056465] Altera DMA 0000:01:00.0: irq: 39
[  129.056466] Altera DMA 0000:01:00.0: request irq: 11
[  129.056467] Altera DMA 0000:01:00.0: BAR[0] 0xc0000000-0xc00001ff flags 0x0014220c, length 512
[  129.056468] Altera DMA 0000:01:00.0: BAR[1] 0x00000000-0x00000000 flags 0x00000000, length 0
[  129.056469] Altera DMA 0000:01:00.0: BAR[2] 0xa0000000-0xbfffffff flags 0x0014220c, length 536870912
[  129.056470] Altera DMA 0000:01:00.0: BAR[3] 0x00000000-0x00000000 flags 0x00000000, length 0
[  129.056470] Altera DMA 0000:01:00.0: BAR[4] 0x00000000-0x00000000 flags 0x00000000, length 0
[  129.056471] Altera DMA 0000:01:00.0: BAR[5] 0x00000000-0x00000000 flags 0x00000000, length 0
[  129.056480] Altera DMA 0000:01:00.0: BAR[0] mapped to 0xffffc900031e6000, length 512
[  129.056978] Altera DMA 0000:01:00.0: BAR[2] mapped to 0xffffc90040000000, length 536870912

 

as you can see,  PCIE message shows " BAR[2] 0xa0000000-0xbfffffff , length 536870912

which means   BAR[2] access address space is  totally “= 0x20000000  bytes = 536870912 bytes "(512MBytes)

 

But our FPGA has 1GB DDR4 ,and we want PCIE BAR[2] can read/write the whole 1GB FPGA DDR4 from Host PCIE interface, so how can we do to implement this ?  Where to config PCIE BAR[2] to access "1gb" address space in paltform designer ?  

 

Thanks a lot

 

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SengKok_L_Intel
Moderator
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Hi


The PCIe IP will auto-detect the BAR size, can you go to “Base Address Registers” -> “BAR 2” -> Size (bit?)? To confirm it is either 29 bits or 30 bits. I connected 1G DDR with BAR2, and I can get 30 bits size for BAR 2.  



Regards -SK


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SengKok_L_Intel
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If further support is needed in this thread, please post a response within 15 days. After 15 days, this thread will be transitioned to community support. The community users will be able to help you with your follow-up questions. 


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