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Hi Stephan,
The byte-write restriction only applies to data cache in
performance version.
So the issue that the customer sees shouldn't be due to
this restriction.
Changing the cache size will have an impact on the
performance and behavior of MicroBlaze.
Do they use interrupts? Interrupts may now hit different
instructions in the code.
Software timing will most likely be different in
the interaction with peripherals.
Are they using
the latest patch for v6.00b?
Could you provide me the .mhs file? I can take a look at
it.
Göran
From: owner-microblaze-uclinux@xxxxxxxxxxxxxx [mailto:owner-microblaze-uclinux@xxxxxxxxxxxxxx] On Behalf Of Stephan Neuhold Sent: Wednesday, April 16, 2008 11:10 AM To: microblaze-uclinux@xxxxxxxxxxxxxx Subject: RE: [microblaze-uclinux] Any known issues with Petalinux and cache lower than 8K Hi
Goran, Thanks, I forgot about
the byte write enables in S3E. Would this apply to
both the instruction and data caches or only the data caches? My apologies, I am
going through the docs to find this out but haven?t been successful
yet. However, my customer
has selected the area optimized version for Microblaze (v6.00b) and still sees
the problem when using anything less than 8K. The problem manifests
itself in software errors, e.g. when they perform their compression algorithm on
some files and read/write that to memory. Any other
ideas? Thanks, Stephan Xilinx
Dedicated Field Applications Engineer Nu Horizons
Asia Tel :
+61 2 9746 1411 Fax :
+61 2 9746 1511 Cell : +61 4
2225 1680 From:
owner- Hi
Stephan, You can't have less than 8kbyte data
caches on a FPGA architecture that doesn't support byte-writes on
BRAMs. This applies for the performance
version of MicroBlaze. The area version can go down to 2kbyte (1 BRAM) even on
architectures that is missing byte-writes. Göran
Från:
owner- Hi, A customer of mine is Petalinux and
has some DDR connected to the system. When the cache is 8K all accesses to
memory appear to be fine. When the cache is lowered to 4K (to
save on BRAMs required elsewhere) they find that the memory accesses get
corrupted. While I know ?corrupted? doesn?t say
much I myself have not investigated in depth how or in what form the corruption
presents itself, however, I wanted to find out whether there were any known
issues with using cache sizes of less than 8K with Petalinux exist or if anybody
had seen similar things happen? As far as I can tell there should be
no issue here. The target device is a XC3S1600E for
reference. Thanks, Stephan
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