Hi My,
the first couple of tests look pretty interesting:
11 and 3 devices are detected.
I can't remember such details so I'd have to check versus
a working board and look for differences in the messages.
Perhaps the latter tests are being performed correctly.
See "TDO seems to be stuck at 1".
Was the corresponding zero ohm resistor R467 removed as well as the
new jumper wires added ?
Matt
On Tue, 20 Oct 2020, My Nguyen wrote:
Date: Tue, 20 Oct 2020 14:23:10 -0700
From: My Nguyen <[email protected]>
To: Matt Dexter <[email protected]>
Cc: [email protected]
Subject: Re: Roach 2
Hi Matt,
I followed your instructions and here is the result (see attached document).
I saw the message repeatedly c:117 and assumed it was C117 under the power PPC chip (U2)
so I replaced it with another one but it still failed. At this point I do not
know what
caused it to fail because when I ran the JTAG boundary scan test with Provision
app a
couple times (for each board) and it passed everything. Please advise.
MY NGUYEN
Digicom Electronics Inc.
7799 Pardee Lane, Oakland, CA 94621.Website: www.Digicom.org.
Direct Line : (510) 668-8443
Main line : (510) 639-7003
Email: [email protected]
On Fri, Oct 16, 2020 at 8:36 AM My Nguyen <[email protected]> wrote:
Good morning Matt,
Thanks for the info. I'll try and see what happens.
Have a good weekend and stay healthy.
MY NGUYEN
Digicom Electronics Inc.
7799 Pardee Lane, Oakland, CA 94621.Website: www.Digicom.org.
Direct Line : (510) 668-8443
Main line : (510) 639-7003
Email: [email protected]
[icon-envelope-tick-green-avg-v1.png]
Virus-free. www.avg.com
On Thu, Oct 15, 2020 at 4:22 PM Matt Dexter <[email protected]> wrote:
Hi My,
I don't know what is going on.
As usual Jack has wise comments.
Alec really understood the JTAG scheme and worked on
the low level diagnostics. He really knew that stuff but
time is rough on all of our memories especially without
frequent refresh cycles.
You were smart to replace the FTDI chip (U33) as
that part caused all sorts of such problems. JTAG's
TDO stuck high due to U33 nonsense comes to mind.
You mention you wisely checked the JTAG Provision itself.
There were all sorts of ?Windows OS? issues with getting
that detected and running. lots of memories of rebooting the PC
un-mating the JTAG gizmo from the PC and
then re-mating it, etc. Silly stuff but cost lots of lost
time.
I scanned old notes and found during some debug sessions
we changed(shortened) the JTAG chain by the use of the
0 ohm resistors on the right hand side of page 26 of the
schematics. See R477, R478, ... R481, and so on.
By removing some particular 0 ohm resistor and adding a
jumper wire then JTAG chain can be (dramatically) shortened.
Instead of the full 11 device chain does it work if
there are only 6 or 3 or ... devices.
For example (I think)
remove 0ohm part from R467 (near U33)
add wire from R478 (either pin; between J7,J7 Mezz) to R467 pad 2.
verify: R478 is 0 ohms to U33-18.
does JTAG chain see something like 3 devices ?
say it does then ...
move wire from R478 to R483 (either pin; near lower left of QDR
2).
does JTAG chain see something like 6 devices ?
and so on.
Other ancient notes also mention the rather un-exciting debug style of
checking all the 0 ohm resistors in the JTAG chain such
as R462, R464, ...
At least 1 such resistor was not zero ohms (due to physical cracking).
U77, U79, and U82 are critical and I think easy enough to
ohm out and probe for toggling JTAG clock or whatever.
U52 and U53 are critical too.
I think a solder blob at U52 caused grief on at least 1 board.
Good luck,
Matt
On Thu, 15 Oct 2020, My Nguyen wrote:
> Date: Thu, 15 Oct 2020 12:07:20 -0700
> From: My Nguyen <[email protected]>
> To: Jack Hickish <[email protected]>
> Cc: Matt Dexter <[email protected]>
> Subject: Re: Roach 2
>
> Hi Jack,
> No problem, I understand.
> Have a great day and stay healthy.
>
> MY NGUYEN
> Digicom Electronics Inc.
> 7799 Pardee Lane, Oakland, CA 94621.Website: www.Digicom.org.
> Direct Line : (510) 668-8443
> Main line : (510) 639-7003
> Email: [email protected]
>
>
> On Thu, Oct 15, 2020 at 12:05 PM Jack Hickish <[email protected]>
wrote:
> Hi My,
>
> Good to hear from you. Things are going OK with me, all things
considered. I hope
> you're doing alright too.
> I think this is a bit above my pay grade. Hopefully Matt can help,
and if you're
> lucky Alec Rust from South Africa will see your message and might
have some words
> of wisdom. But I fear very few people have any ROACH2 wisdom still in
their
> memories.
>
> Sorry to not be more help.
> Jack
>
> On Thu, 15 Oct 2020 at 19:35, My Nguyen <[email protected]> wrote:
> Hi Matt and Jack,
> I hope you are all well and safe.
> I have an issue with the Roach 2 boards (qty 3) and I don't know why.
The
> board passed all steps except the JTAG scan chain test. When I run
the JTAG
> boundary scan test on JTAG Provision itself then it's passed. I
replaced the
> FTDI chip (U33) but it still failed. Do you know what's going on?
> Best regards.
>
>
> MY NGUYEN
> Digicom Electronics Inc.
> 7799 Pardee Lane, Oakland, CA 94621.Website: www.Digicom.org.
> Direct Line : (510) 668-8443
> Main line : (510) 639-7003
> Email: [email protected]
>
>
>
[icon-envelope-tick-green-avg-v1.png]
Virus-free. www.avg.com
--
You received this message because you are subscribed to the Google Groups
"[email protected]" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/alpine.WNT.2.20.2010201428310.7616%40DESKTOP-LM78PCL.
