Hi group
I have constructed an opto-isolator that goes into the cable from the USB-TAP. I
used it to
debug a 5kW buck converter (600V in, 0-250VDC out) for deep sea diving suits.
The whole setup literally exploded several times without damaging the JTAG.
I'll be happy to release some Gerbers if I can find them.
I have a question for you - now that you are talking reset circuitry.
I have a 56F8365 connected directly to the JTAG pin to pin (with the obvious
pullup).
When I compile and download, the processor only about half of the times come up
at
the first line of the code. Otherwise it runs wild somewhere. I have to
recompile, sometimes
2-3 times before it works. I recall seeing reset circuits on the developer
board, but they only
seem to affect the power up reset. Any clues?? (Using USB TAP)
Another puzzlement is that I tried to downscale my processor and put
56F8345's in some
boards, replacing the 56F8465. Every single one of them refused to program.
Why?
Kent
On 12 Sep 2008 at 15:52, Barnard Adam wrote:
>
> adam.barnard_ch wrote:
>
> > Hi Carlo,
> >
> > I am using the MC56F8367. When I started using the device, I created
> > structures for addressing the hardware registers of the peripherals
> > directly. After some playing around with the lincer command file I
> > finally got it running on the Freescale DemoBoard. But when I
> > downloaded the code to my hardware, I also received the message: Core
> > not responding. In my case the problem was that the CodeWarrior
> > software automatically initialise ALL variables to zero: In this case
> > also ALL the DSP Registers! I could not prevent the software from
> > doing it - even after commenting out the ZERO_BSS subroutine. Now I
> > am using pointers to structures for addressing the registers and it
> > works fine. No "core not responding" messages anymore.
>
> Could you program the DSC after this happened? We had to REPLACE it
> (desolder/solder a new one) every time because it wouldn't respond
anymore,
> even after power cycling and some cooling; and it happened randomly once in
a
> couple of days or so (we have a stock of a dozen devices). Yes. Up to now I
have not
> lost one single DSP. (I use the CodeWarrior USB TAP) With my H-Bridge I did
not
> have the same success ;-)
>
> > So I suggest that you look at the initialising of the clocks and PLL
> > etc. Also at the implementation of your reset circuitry.
> >
> > Another question: Do you have a watchdog enabled? Is your watchdog
> > disabled when you try to download new code? A watchdog reset will
> > definitely also cause a "Core Not Responding" error.
>
> Watchdog disabled; as far as I know reset circuitry is as found on the data
sheet.
>
> Thanks for the reply and best regards,
> Carlo.
>
> > --- In m...
> > , Carlo wrote:
> > >
> > > Hi,
> > >
> > > me and my research group are working towards developing a hybrid
> > > vehicle, where the electric powertrain is driven by a 56F8323
> > Freescale
> > > DSC.
> > > We frequently have to reprogram the DSC, and once in about ten or
> > twenty
> > > reprograms the DSC would stop working and give "Core not
> > responding" and
> > > "Failed to write to FLASH" errors; at this point the only remedy is
> > to
> > > replace the DSC (DSC fried). Anyone experienced the same problem?
> > >
> > > I don't know why this happens, we think some weird ground loop but
> > how?
> > > The vehicle is battery operated and when we program the DSC it sits
> > on a
> > > bench isolated from ground...
> > > Then a colleague brought us an optoisolated programmer like this
> > one:
> > >
> > > http://cgi.ebay.it/ws/eBayISAPI.dll?
> >
> > ViewItem&item20296958416&ssPageNameME:L:LCA:IT:1123
> > >
> > >
> > >
> > > with this programmer it's been two days without problems! It works
> > > great. This confirms the ground loop hypothesis.
> > > Freescale used to sell optoisolated programmers but now they don't
> > sell
> > > them anymore. I think this is the only optoisolated programmer for
> > > Freescale DSC on the market. We already contacted the manufacturers
> > to
> > > buy one.
> > >
> > > Anyone had similar problems? Any thoughts?
> > >
> > > Regards,
> > > -- Carlo.
> > >
> >
> >