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Altera_Forum's avatar
Altera_Forum
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14 years ago

Question on PCIE compiler

I set up a project based on "Arria II GX FPGA Development Kit, 6G Edition (EP2AGX260)". I encountered a problem: when I config the PCIE IP with a BAR space larger than 256MBytes, the WinDriver...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

On 32 bit Windows XP/Vista/7, there are two limitations.

- As you said, there's a 4 GB physical address space that is shared by physical RAM and devices. Since you only have 2 GB of physical RAM, it's unlikely this is the cause -- unless you have tons of other devices.. ?

- The kernel has a 2 GB virtual address space into which is must map the kernel's code and data structures, plus the devices. This would be a more likely cause-

Additionally, I'm not sure if Windows or WinDriver even allow spaces larger than 256 MB.

I say that because, as far as I can see , even graphic cards with 1GB of RAM only expose a 256 MB space.

In any case, it looks like an OS/Windriver limitation, not a firmware problem.