Forums

bootloader problem (002)

Started by dp19...@elbit.co.il January 4, 2006

thanks jeff,

hello all.

I have checked pullups and pulldown values for bootmode, TRST, RESET. They all seem OK.

all VCC, VCORE, clocks aer stable, no excessive ripple.

I found nothing to be wrong or different from another cards that do work. I am trying now to put the failing device on another card, to see if the problem goes with the device itself. I am not optimistic, since we produce a whole lot of cards designed with this processor, and we never saw this problem in any other design.
The only time we saw something closely similar to this was when we forgot to put a pulldown on TRST. but this produced the problem differently (no DMA load at all). any way, i tried to tie this pin (TRST) to ground with a zero ohm resistor, and it made no difference.

Does any body have another idea?

Maybe in the JTAG area?

Thanks

Dror


Hello Dror,

FYI - it is usually helpful if you keep the email
thread [via reply all] to preserve history. Some of
us are very busy and deal with a lot of different
issues during a day - maintaining the 'history' will
increase your chance of a reply [for example, this
message does not even contain the DSP family or part
number].

see below.

--- dp19188@dp19... wrote:

>
> thanks jeff,
>
> hello all.
>
> I have checked pullups and pulldown values for
> bootmode, TRST, RESET. They all seem OK.
>
> all VCC, VCORE, clocks aer stable, no excessive
> ripple.
>
> I found nothing to be wrong or different from
> another cards that do work. > I am trying now to put the failing device on another
> card, to see if the problem goes with the device
> itself. I am not optimistic, since we produce a
> whole lot of cards designed with this processor, and
> we never saw this problem in any other design.
> The only time we saw something closely similar to
> this was when we forgot to put a pulldown on TRST.
> but this produced the problem differently (no DMA
> load at all). any way, i tried to tie this pin
> (TRST) to ground with a zero ohm resistor, and it
> made no difference.
>
> Does any body have another idea?
What rev is your part??
On the failing boards, do you have an EMIF clock out??
I still think that Jeff was on the right track. Flash
boot on a 6713 is executed by a state machine - if
configured properly with nothing but a DSP, the flash
boot will DMA 1024 bytes. The prerequisite for this
is all DSP hardware setup [assuming that the DSP
works] - reset pulse width & rise time, voltages, PLL
[check/swap ext components]
>
> Maybe in the JTAG area?
If nTRST is pulled low, JTAG is disabled.

mikedunn
>
> Thanks
>
> Dror >
>
> c6x-unsubscribe@c6x-...




Dror-

> I have checked pullups and pulldown values for bootmode, TRST,
> RESET. They all seem OK.
>
> all VCC, VCORE, clocks aer stable, no excessive ripple.
>
> I found nothing to be wrong or different from another cards that do work.
>
> I am trying now to put the failing device on another card, to see if the
> problem goes with the device itself. I am not optimistic, since we
> produce a whole lot of cards designed with this processor, and we never
> saw this problem in any other design.
> The only time we saw something closely similar to this was when we forgot
> to put a pulldown on TRST. but this produced the problem differently (no
> DMA load at all). any way, i tried to tie this pin (TRST) to ground with
> a zero ohm resistor, and it made no difference.
>
> Does any body have another idea?

Yes if possible I would try swapping first DSPs between working and non-working
boards, then the Flash device the DSP boots from. The problem sounds strange and
intermittent enough that the best approach may be to find anything that all that
affects it, then go from there.

-Jeff

PS. Please include the thread history as Mike suggests. You have an interesting and
unusual problem but people who didn't see posts the last couple of weeks would not
get a chance to know about it.