External Memory Controller -- certain address ranges don't work?
I have experienced the following with Microblaze in Virtex 4 LX25, and PPC in Virtex 4 FX12:
Memory test application and manual access to external asynchronous SRAM seems to fail when I assign certain address ranges.
For example, testing of a 1MB address space assigned to start at 0x10000000 fails, but if I move it to 0x84000000 it will work just fine, with no other changes to the hardware.
The address maps I was using were brought in from a project using an older version of Microblaze on Virtex II, where it worked just fine... since the address mapping is pretty arbitrary, I don't mind just changing it to something that works, but I am curious if there is a reason why. Does anybody have any ideas?