custom board jtag programming

Giuseppe Giancola1

Other Parts Discussed in Thread: TM4C123GH6PM, SEGGER, EK-TM4C123GXL, UNIFLASH, LMFLASHPROGRAMMER

hi I'm trying to program a custom board with a TM4C1231H6PMI using the TivaC Launchpad JTAG header but both CCS and LM Flash programmer don't recgnize the device. I based the circuit on the tivaC schematics, so what could be the problem? with LM flash i've error - unable to initialize the target- 0; with ccs Error connecting to the target
i've controlled the connections of the jtag pins with a multimeter and the voltages, but everything seems ok
in the schematic attached there is a part of the circuit

thanks

Edit: shoul I use the ICDI debug interface on the back of the board?

over 11 years ago

0 Giuseppe Giancola1 over 11 years ago

Intellectual 730 points

UPDATES: i can program using jtag, i use the two pullup resistors on tck and tms and joining the gnd signal on the two boards, now the uart seems not to function, is there a way to make it works? I've read that the jtag is only out, it causes problems also with the uart?

thanks

0 Michael Jensen over 11 years ago in reply to Giuseppe Giancola1

Intellectual 485 points

Hi,

from my point of view you are missing pull up/down resistors on both JTAG and UART0.

UART0 RXD should have a pull up resistor otherwise it may detect a BREAK or noise.

On the JTAG port, pins TCK, TMS and TDI are inputs and should should be pulled. Pin TDO is output.

This is my standard connections for these and it has been working for more than 10 designs.

BTW, your 3.3V regulator seems to be a 5V version. I hope it is not.

0 Giuseppe Giancola1 over 11 years ago in reply to Michael Jensen

Intellectual 730 points

hi Desvig thanks for your answer and your schematic, i've seen on the tivac schematics that there are only two pull up resistors on tck and tms, instead you use a pull down on tck,more you use two schmitt buffers on txd0 and rxd0, should I try with two pull up resistors also with these two pins?

the voltage regulator that i use is 3.3

0 Michael Jensen over 11 years ago in reply to Giuseppe Giancola1

Intellectual 485 points

Hi,

the info on the JTAG is collected from the MCU datasheet, my Keil ULINK 2 datasheet and several years use of Altera FPGA/EPLD. Since a resistor costs nothing, I put it there to be sure and I have never had problems with JTAG. Remember TDI is also an input on the MCU and TDO is connected to an input on another device. In general JTAG can be very noise sensible.

For RXD0 I would recommend a pull up. It shouldn't be necessary for TXD0. The reason for the buffers are, that I normally don't like a direct connection from the MCU to an external connector. It also makes the RXD line less sensible to noise, ground bounce etc.

0 Giuseppe Giancola1 over 11 years ago in reply to Michael Jensen

Intellectual 730 points

Thanks Desvig,

i used the pull down on TCK and pull up on TMS, TDI and RXD...it works! thank you so mutch!

0 Mitesh Sirodaria over 11 years ago in reply to Giuseppe Giancola1

Intellectual 880 points

Hello,

I am new to Jtag but as of now I am trying to build a new circuit. So please don't mind if my questions are bit silly.

If I bring this JTAG connection out and if I make a USB to JTAG convertor using FT232HL bringing out JTAG pin, can I directly program my TM4c123GH6PM controller or do I need some software or program?

Thank you,

0 Amit Ashara over 11 years ago in reply to Mitesh Sirodaria

TI__Guru**** 244400 points

Hello Mitesh,

Yes, it will work. I know OPENOCD supports FTDI chips for TIVA debug and so does CCS. But do make sure that the VID/PID and programming of the EEPROM of FTDI is correct.

Regards

Amit

0 Mitesh Sirodaria over 11 years ago in reply to Amit Ashara

Intellectual 880 points

Thanks Amit for your reply, but is there any other option to load a program in my controller without using FTDI chips.

0 Mitesh Sirodaria over 11 years ago in reply to Mitesh Sirodaria

Intellectual 880 points

Hi Amit,

I got one of your post through which we can make a use of TM4c123GH6PM launchpad as debugger. Can I use it here instead of FT232HL?

And to make it succesful I just need to connect those 4 JTAG pins of launchpad to 4 JTAG pins of my new controller right?

This is the link where I got this information

http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/t/319187.aspx

Thank You.

0 Amit Ashara over 11 years ago in reply to Mitesh Sirodaria

TI__Guru**** 244400 points

Hello Mitesh,

FT232 is a FTDI chip. Other than you can use XDS100 or any other vendor like Keil, Segger.

Regards

Amit

0 Amit Ashara over 11 years ago in reply to Mitesh Sirodaria

TI__Guru**** 244400 points

Hello Mitesh,

Yes you need to connect the 4 JTAG Pins and it can be used as a debugger. We have tested it.

Regards

Amit

0 cb1_mobile over 11 years ago in reply to Amit Ashara

Guru 117855 points

@ Devsig,

Like you - we've used JTAG beyond 15 years - starting w/FPGAs. And - we agree whole-heartedly that external pull-up Rs tied to JTAG input pins prove, "worth their weight/cost in gold!"

Your neat schematic shows 100K for those pull-ups - we've found that value too high - thus rendering JTAG signals, "susceptible" to adjacent noise sources. Our usage reveals "at/around 10K pull-up R values" provides better noise resistance/immunity. (as compared to 100K or MCU's internal "weak pull-ups" - which we never trust nor employ) Surely your 100K values have & will work - but our review - across multiple scientific, industrial & medical setting clients - has revealed that the 10K values do improve noise margin...

0 Janos over 11 years ago in reply to Mitesh Sirodaria

Intellectual 570 points

Mitesh Sirodaria said:

This is the link where I got this information

http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/t/319187.aspx

Hi Mitesh,

this is where i got the information about using the LaunchPad as a debugger: http://processors.wiki.ti.com/index.php/Stellaris_LM4F120_LaunchPad_Debug_How_To

It is for the Stellaris LaunchPads, but same thing with the TIVA LaunchPad.

Cheers

Janos

0 Sham Sunder over 10 years ago in reply to Amit Ashara

Prodigy 130 points

Hello everyone,

Sorry for again asking similar query but wanted to confirm before hardware manufacturing of my custom board. I am designing TM4C1231H6PMI7 based custom board. I want to use EK-TM4C123GXL launchpad as external debugger/programmer for the controller (on my custom board).
It is not exactly clear to me should i connected only 4 JTAG signals from launchpad to my custom board for this job or i need to connect other signals as well such as UART0 signals (Rx n TX) and GND (I think i should), RESET, and EXT-DBG from launchpad to custom board.

Additionally, please guide which signals to pull-up and which to pull-down. From schematic of launchpad i was assuming i don't need to do it, as it is already done on debugger side (for TCK and TMS).

Thanks

0 Amit Ashara over 10 years ago in reply to Sham Sunder

TI__Guru**** 244400 points

Hello Sham,

I would strongly suggest using an external programmer like XDS100 with Uniflash to program the device with the production image.

It is possible to re use the EK-TM4C123GXL, but do note that loose wires, improper GND may bring more issues on the final production rig as compared to a solid connector.

Regards
Amit

0 Sham Sunder over 10 years ago in reply to Amit Ashara

Prodigy 130 points

Thanks Amit for reply and suggestion. Actually i have implemented DFU USB programmer (with LMFlashprogrammer) for custom board for normal firmware change , but i want to keep a backup as well in case a problem with DFU or for the need of Debug (in rare case). I can't increase overall system cost for just backup feature. So please suggest me the connection to share between the launchpad and custom board in order to do that.
Thanks again

0 Amit Ashara over 10 years ago in reply to Sham Sunder

TI__Guru**** 244400 points

Hello Sham,

Following post will help.

e2e.ti.com/.../341504

Regards
Amit

0 Mitesh Sirodaria over 9 years ago in reply to Amit Ashara

Intellectual 880 points

Hello All,

I am also trying it again to flash my custom board with TIVA LAunchpad using JTAG.

I have checked with my jtag pins and pull up resistors on jtag pin. connection looks ok but I am unable to flash my board.

Initially it was showing connection error on both LM Flash Programmer and CCS but now after few trails I am facing an another issue that it starts uploading but it stucks somewhere after that. and after few seconds I receive a message on CCs with below errors inn console window.

CORTEX_M4_0: GEL Output:
Memory Map Initialization Complete
CORTEX_M4_0: Error occurred during flash operation: Timed out waiting for target to halt
CORTEX_M4_0: Flash Programmer: Timed out while writing to Flash memory
CORTEX_M4_0: File Loader: Memory write failed: Unknown error
CORTEX_M4_0: GEL: File: F:\workspace\blinky\Debug\blinky.out: Load failed.

It would be great if someof you can help me out with this.

0 Mitesh Sirodaria over 9 years ago in reply to Mitesh Sirodaria

Intellectual 880 points

I am again getting an issue of Error Connecting the target.

0 Giuseppe Giancola over 9 years ago in reply to Mitesh Sirodaria

Prodigy 40 points

check the jtag pull up/down resistors:

tck -> pull down

tms, tdi ->pull up

0 Amit Ashara over 9 years ago in reply to Mitesh Sirodaria

TI__Guru**** 244400 points

Hello Mitesh,

Also do check the JTAG connections of TDI and TDO...

Regards
Amit

0 Mitesh Sirodaria over 9 years ago in reply to Amit Ashara

Intellectual 880 points

Thanks all for replying. Circuit had an issue with decoupling capacitors. It worked now.

Thanks all,

Mitesh

0 Amit Ashara over 9 years ago in reply to Mitesh Sirodaria

TI__Guru**** 244400 points

Hello Mitesh

Since this issue is going to pop up on the forum, can you let us know which decoupling caps?

Regards
Amit

0 alex gonzalez over 9 years ago in reply to Giuseppe Giancola1

Prodigy 90 points

I have a question on how you got JTAG working? I have an launchpad connected to my custom board but run into the following error
"Cortex_M4_0: Error Connecting to Target"

0 Amit Ashara over 9 years ago in reply to alex gonzalez

TI__Guru**** 244400 points

Hello Alex,

Which LaunchPad connected to which custom device, how is the JTAG connected.

Please also look at ISSUE#4 and 5 in the following post

e2e.ti.com/.../374640

Regards
Amit

0 alex gonzalez over 9 years ago in reply to Amit Ashara

Prodigy 90 points

Hello Amit,

I am using the Tiva C Series TM4C123G launchpad the custom device is using the TM4C123GH6PM microcontroller. The JTAG is connected from the launchpad to the custom device as follows:
TCK--TCK
TMS--TMS
TDO--TDO
TDI--TDI
RST-RST

RST works it is set as a High Until pressed on either the launchpad or the custom device.

I have checked continuity and I am receiving signals over based on results from a Saleae.
The error I continue getting is:
"Cortex_M4_0: Error Connecting to Device"

0 Amit Ashara over 9 years ago in reply to alex gonzalez

TI__Guru**** 244400 points

Hello Alex,

Did you power down the Main MCU on the EK-TM4C123GXL by removing the jumper header?

Regards
Amit

0 alex gonzalez over 9 years ago in reply to Amit Ashara

Prodigy 90 points

Hello Amit,

The Jumper is removed so that I can strictly use the Debugger. I am able to use JTAG well between two launchpads and currently troubleshooting to make sure that I did not overlook a process.
Also I looked at issues #4 and #5,

Also Checked off everything that was in Issue#4
The Stellaris_ICDI_Drivers are installed and Updated

Repectfully,
Alex

0 Amit Ashara over 9 years ago in reply to alex gonzalez

TI__Guru**** 244400 points

Hello Alex

A picture of the connections would be useful as well. I have a document you may find useful.

Regards

Amit

EK-TM4C123GXL_Debugger.docx

0 alex gonzalez over 9 years ago in reply to Amit Ashara

Prodigy 90 points

This is how it is currently connected following this post I will be attaching the schematic made for the custom board to better illustrate the connections for the pull-up resistors, reset switch, decoupling capacitors, and the capacitors for the external crystal.

Respectfully,

Alex

0 alex gonzalez over 9 years ago in reply to alex gonzalez

Prodigy 90 points

Hello Amit,

Here is the additional schematic for the custom boards JTAG Connections.

Respectfully,

Alex

0 Amit Ashara over 9 years ago in reply to alex gonzalez

TI__Guru**** 244400 points

Hello Alex

The connections look correct as per the documentation I sent out to you. What about the VDDC pins, are they connected to the required 2.5-4.0uF of decoupling capacitor?

Also when you connect the debugger, do you have a snapshot of the 4 JTAG lines on a Scope?

Regards
Amit

0 alex gonzalez over 9 years ago in reply to Amit Ashara

Prodigy 90 points

Hello Amit,

I have the following values & results I am using for the uC's VDDC I am measuring a voltage of 0.09 mV. I believe I might have shorted the uC. But the other pins for the VDD is measuring at the expected 3.3 volts. I believe I might just have to remove the uC and re-solder a new uC it down if there are no other suggestions.

Apologies for the late response.

Respectfully,

Alex

0 Amit Ashara over 9 years ago in reply to alex gonzalez

TI__Guru**** 244400 points

Hello Alex,

VDDC must be 1.2V and as you suspect, a short may have caused the issue. Also I noted in the schematic that XOSC0 is open and XOSC1 is connected to GND. If not being used then XOSC0 should be connected to GND and XOSC1 should be left NC.

Regards
Amit

0 alex gonzalez over 9 years ago in reply to Amit Ashara

Prodigy 90 points

Hello Amit,

The uC was a goner, replacing that part fixed the problems. Thanks for your suggestions and comments on the schematic and layout. JTAG works now and I am able to connect to the target device.

Respectfully,
Alex

0 Amit Ashara over 9 years ago in reply to alex gonzalez

TI__Guru**** 244400 points

Hello Alex,

But it does bring up the question: How did it get damaged in the first place!!!!

Regards
Amit

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