Weird. My understanding is also that the PPC uses the 100 MHz
crystal and should be unaffected by the lack of (or corruption of)
the ADC clocks. Maybe the ADC clock domain had problems that
affected the power to the chip (e.g. by draining the decoupling caps
due to bizarre clocking); one good power glitch and the CPU could
easily get hosed.
Or maybe its some sort of Karmic punishment for something you did in
a previous incarnation... :-)
Dave
On May 30, 2008, at 12:00 , G Jones wrote:
Nope, I have added software in the past, but as soon as I started
having this problem, I have just been running default builds.
Hmm, now it looks like this problem was due to the ADC clock DCM
not locking, because when I reduced the ADC clock to 400 MHz I was
able to get the designs to run OK. Then when I brought the ADC
clock back up to 1024 MHz, the designs still program and work OK.
While I can understand jitter or other effects causing timing
problems with a design that theoretically meets timing at these
frequencies, what I do not understand is why this would cause the
PPC to not boot or give any indication that it had booted at least.
Doesn't it use the 100 MHz on board oscillator? It seems like the
PPC would work no matter what. Certainly when the ADC clock is
disconnected, I can still access the PPC. Any clues as to what
could be going on here?
Thanks again for the help,
Glenn
On 5/30/08, David MacMahon <[email protected]> wrote: Have
you added extra software in the new design that might be locking up
the PPC?
Dave
On May 30, 2008, at 11:37 , G Jones wrote:
Dave,
Thanks for the suggestion but I always make sure my designs meet
timing before I run them. I have also looked for any differences in
warnings during compilation and have not seen anything yet.
Glenn
On 5/30/08, David MacMahon <[email protected]> wrote: Hi,
Glenn,
The first place I would check is the timing report (or par log) to
make sure the new builds are meeting timing.
Dave
On May 30, 2008, at 11:14 , G Jones wrote:
Hello,
I expect the only way I'll solve this is through careful
experimentation, but I wanted to check to see if anyone had any
tips on what might be going on with my iBOB designs. A few days
ago, I started having trouble where when I compiled and downloaded
a design to the iBOB, "Nothing" would happen, that is no output
from the serial port, no response from LWIP, but the LEDs generally
behaved as expected for the design. Here is what I know:
The board still seems to work fine: When I press the "prog" button,
it successfully loads the design stored in the PROM. Also when I
load an older design from a few weeks ago, it runs without trouble.
However, once I load a newly compiled design I get this odd
behavior where the serial port and ethernet ports are unresponsive.
Once this happens, if I try to load another design which worked
before, the ports remain unresponsive until I press the "prog"
button, after which old designs work fine again.
When I compile a simple design that basically just connects the ADC
to a snap64 block, I can download and run it just fine. However,
recompiling a more complicated design like a spectrometer leaves
the iBOB unresponsive. A bit file from the same design compiled a
while ago still runs fine on the iBOB.
I just noticed that the newly compiled spectrometer design is not
drawing as much current as the originally compiled, working version.
Any clues as to what I could have messed up with my tool flow? I
wonder if I accidentally installed a new conflicting version of
cygwin or something like that which is generating corrupt bit files.
Thanks,
Glenn
