25 Apr
2014
25 Apr
'14
5:36 p.m.
Hi Craig,
I got JTAG working (thanks to #osmocom!). I first recommend you get a C115
or C118 with JTAG exposed, which is much easier than having to remove the
shields. However remove the plastic cover which makes soldering GND, TDI,
TMS, TDO & TCK easier - be careful not to short them the surrounding
shields! You will see there is actually 8+9 pads, you must disregard the
pin that is left of CTS (it is not shown on
http://bb.osmocom.org/trac/raw-attachment/wiki/MotorolaC123/compal_testpads…).
Finally you need a proper VREF. As for me, I just connected the internal
3.3V (TP4) on my Flyswatter2 to the VREF, it appears to work fine (the
Flyswatter1 has a jumper that you can use to bridge VREF and 3.3V).
On Fri, Oct 4, 2013 at 5:08 PM, Craig Comstock <craig_comstock(a)yahoo.com>wrote;wrote:
I cracked open the shield on my C139 and didn't
see the TPs I expected
from the schematic. I thought maybe the angle of the photo on osmocom hid
the TPs but it really didn't.
I'll try my C115 instead since that is more clear and accessible. Flashing
hello_world on my C115 seemed to fail in a similar fashion as it does on my
C139 so maybe the same issue exists there.
I was wrong too... it was TP16 not TP6, so I found TP16 but still haven't
located TP8 on the C139 schematic.
-Craig
------------------------------
*From:* Craig Comstock <craig_comstock(a)yahoo.com>
*To:* "baseband-devel(a)lists.osmocom.org"
<baseband-devel(a)lists.osmocom.org>
*Sent:* Thursday, October 3, 2013 9:57 AM
*Subject:* c139/c140 jtag anyone?
I'm at the point w/ flashing firmware where I feel like I need to use a
debugger w/ JTAG. I figured I could probably use serial line logging
somehow but JTAG seems better and I should learn it anyway.
Has anyone pried open the shield on a c139/c140 and tried attaching to the
JTAG test points that are just inside the shield next to the test points
which are accessible via the battery compartment?
From what I can gather from the schematics:
TDI - TP8
TCK - TP17
TDO - TP16
TMS - TP18
Looking at the board from the battery compartment side with the top of the
phone pointing North/Up I see at least TP17 is near the right-hand bank of
test points visible from the battery compartment. From left-to-right there
I see something like: TP12, TP18?, TP16?, TP17 so it looks like I have two
of the TPs I need: 17 and 18.
I can't seem to find TP6 or TP8 anywhere on the schematic.
-Craig