topic Re: Secure JTAG in imxrt1050-EVKB in i.MX RT Crossover MCUs

Secure JTAG in imxrt1050-EVKB

vanessa_dis — Thu, 10 Jun 2021 21:15:53 GMT

Hello

I'm using an IMXRT1050-EVKB REV A1, and the micro said MIMXRT1052.

I did the fuse configurations described here https://www.nxp.com/docs/en/application-note/AN12419.pdf.

and I've read that J32 and J33 should be removed, so I removed those jumpers.

And when I tried to debug in MCUExpresso (without run script in j-link) it let me debug like this image.

(i'm using JTAG connector on J34)

I don't know if it would be like this, i mean, if this is correct.

And if I try to run the script, it didn't identify UUID0 and UUIDD1, it doesn't matter if I put JTAG_MOD in 0 or 1, it never find UUID's

I'm not sure what steps I have to follow then, because I just blown the fuses in the manual.

I hope you can help me,

Thanks

Re: Secure JTAG in imxrt1050-EVKB

kerryzhou — Fri, 11 Jun 2021 06:50:03 GMT

Hi @vanessa_dis

Seems you also read this post:

https://community.nxp.com/t5/i-MX-RT/Secure-JTAG-mode/m-p/974136?commentID=1225729&et=watches.email.outcome#comment-1225729

Do you also follow these hardware modification:

1） Burn fuse DAP_SJC_SWD_SEL from ‘0’ to ‘1’ to choose JTAG;

2） DNP R323,R309,R152 to isolate JTAG multiplexed signals.

3） Keep off J47~J50 to isolate board level debugger.-> your board should be j29-j32

Seems you already burn the fuse, in fact, normally, I will suggest the customer let the JTAG mode works at first, then check the secure JTAG again. Anyway, please modiy my point 2 and check it again, that will related to the JTAG mode.

Any updated information from your side, please kindly let me know.

Kerry

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Fri, 11 Jun 2021 14:18:03 GMT

Hi Kerry

Are you sure about theses resistors? I looked at schematic and I saw it was about ethernet not JTAG

I saw it here

Other thing.. is a must remove J29? because I only have an USB cable (Micro B) to power it, and if this jumper is removed the board doesn't turn on. Or how can I turn on the board without J29?

Re: Secure JTAG in imxrt1050-EVKB

kerryzhou — Tue, 15 Jun 2021 07:00:34 GMT

Hi @vanessa_dis

Yes, I am sure, as I have tested the JTAG on my side, that's why I tell you.

If you check the ENET_INT, ENET_RST, you will find it is also the JTAG pins, that's why we need to modify the resistor, and before I reply you, I also check your board version, 2） DNP R323,R309,R152 to isolate JTAG multiplexed signals. it is correct, just do it.

Please also note, DAP_SJC_SWD_SEL need to modify from 0 to 1.

From your picture, you already do it.

So, now, you need to modify the resistor.

Any updated information from your side, kindly let me know.

Best Regards,

kerry

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Tue, 15 Jun 2021 16:32:57 GMT

Thanks Kerry,

I burned the following fuses like the instructions.

Now I just removed the resistors that you mention but it looks the same, like the beginning of post

But note that I keep the J29 connected, because without it, it doesn't have power.

Other thing that it's important to say is that I removed the R303, but i don't think that this is the problem because I manually alternate JTAG_MOD

Kind regards,

Vanessa

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Tue, 15 Jun 2021 17:04:59 GMT

****Actualization: Well, after change the power supply to USB_OTG with J1, now I can't debug (and it's correct because of Secure JTAG). But now in J-link it doesn't connect with target.

Re: Secure JTAG in imxrt1050-EVKB

kerryzhou — Wed, 16 Jun 2021 07:27:45 GMT

Hi @vanessa_dis

1. to your MIMXRT1050-EVKB revA1, j29 is the SDA_RST_TGTMCU_B pin，you can don't disconnect it, but it should not related to the power.

Please check your board, do you J29 is the SD_RST pin? I just want to confirm your board version.

2. R303 is connect the 10K GND to the JTAG_MOD, you can't disconnect it, as this pin has the internal 100K pull up.

You testing flow is really not very correct, you should let the JTAG mode works at first, then test the secure JTAG by modifying the secure fuse.

3. Please give me a photo of your board, I need to check your board version, you mentioned MIMXRT1050-EVKB REVA1.

J1 5-6 connect, it will use the J28 to power on the board.

But, from your picture:

Your VTref is 0V, it is not correct, you still need to check your board power:

Seems your JTAG_VREF, DCD_3V3 no power.

Do you connect J1 2-3?

This is my board which is the JTAG without the secure result:

For the secure JTAG, you can refer to the AN12419, Fig 5,6,7, you can find the VTref is also 3.3V, but you are 0.

Best Regards,

kerry

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Wed, 16 Jun 2021 21:29:42 GMT

Thanks for your answer Kerry,

With this configuration, it looks like the beginning, V==3.3 V and UUID is no identified. That's how I tested in the beginning of my problem.

With this configuration It looks like the previous photo in J-link, that V=0, it make a sense because SDA doesn't have Voltage for JTAG.

I'm using J34 because I don't have the adapter for J21.

Am I doing wrong? I think is the first configuration, because with this detect my target, but it doesn't recognize UUID.

Thanks and regards,

Vanessa

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Wed, 16 Jun 2021 21:43:05 GMT

With the first configuration...

checking JTAG, it seems correctly

key validation for secure JTAG:

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Wed, 16 Jun 2021 21:48:08 GMT

Re: Secure JTAG in imxrt1050-EVKB

kerryzhou — Thu, 17 Jun 2021 05:35:52 GMT

Hi @vanessa_dis ,

Please double check quickly, which JTAG interface you are using?

From your picture, seems you connect to J34?

Please note, J34 is not the RT1050 chip JTAG, it is your on board K20(debugger ) JTAG,

You need to use J21 as the RT JTAG:

This is the key point, please also check your JLINK commander, you can find you find the ARM cortex M4 core, it is the K20, RT is ARM cortex M7 core.

Any updated information from your side, please let me know.

kerry

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Thu, 17 Jun 2021 23:19:51 GMT

Thanks for your help Kerry.

That explain a lot.

Yes, you're right, I tried with J21 and now it detects the target. Although, it appears like this. With this error:

TotalIRLen = ?, IRPrint = 0x..000000000000000000000000

If I try doing key validation, and put JTAG_MOD=1, it's the same

Thanks a lot Kerry,

Vanessa

Re: Secure JTAG in imxrt1050-EVKB

kerryzhou — Fri, 18 Jun 2021 07:04:58 GMT

Hi @vanessa_dis

Do you totally follow the chapter 4 Debugging with the Secure JTAG enabled steps on your side?

In my memory, I test it with the validation board, it works OK.

Do you already manually control the JTAG_MOD like the AN12419 mentioned?

The following are my test result, seems your Lock side still have issues, just share my pictures at first from my previous testing(about two years ago):

Please check your situation with my previous testing result.

Best Regards,

kerry

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Fri, 18 Jun 2021 13:56:15 GMT

Yes Kerry, I followed the chapter 4 Debugging with the Secure JTAG.
And yes, I control JTAG_MOD manually with TP11.

Well. like I see, is the same modification of fuses as mine.

Even I have a custom board, I only burn fuse DAP_SJC_SWD_SEL from ‘0’ to ‘1’ to choose JTAG (I haven't select Secure JTAG yet) . And it has the same problem. Appears the same when I tried connect via JTAG.

Thanks,

Vanessa

Re: Secure JTAG in imxrt1050-EVKB

kerryzhou — Tue, 22 Jun 2021 02:25:23 GMT

Hi @vanessa_dis,

Thanks for your updated information, from your fuse, even similar to my test result previously which I have tested with the internal validation board.

Now, let's talk step by step with your customer board, which just burn fuse DAP_SJC_SWD_SEL from ‘0’ to ‘1’ to choose JTAG , to that board, before you didn't burn fuse, do you can use the JLINK SWD to find the ARM core or not?

If yes, now, just burn SWD fuse, can't connect with JTAG, right? What about JTAG_MOD? It should be pulled low. Please also note the related JTAG other pins,

Then give me the jlink command test result.

Best Regards,

kerry

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Tue, 22 Jun 2021 04:25:57 GMT

Thanks for your answer Kerry,

Yes, exactly, I used to debug with SWD.

And Yes, I removed the resistor to JTAG_MOD ( I shouldn't have done that), but in SWD when I manually put JTAG_MOD to GND, it worked very well. Then I changed that to JTAG, and after the error I soldered again that resistor, I tried with that and also I have tried to put manually to GND (as SWD).

This is my log

About the others pins: TMS, TCK, TDO, TDI are directly connected to JLINK, and TRSTB is connected with a resistor to Vcc

Thanks and regards,

Vanessa

Re: Secure JTAG in imxrt1050-EVKB

kerryzhou — Wed, 23 Jun 2021 07:14:56 GMT

Hi @vanessa_dis

Thanks a lot for your effort.

So, to TCK, TMS, TDI, TDO, no external circuit, connect to JLINK JTAG directly. TRSTB pull to VDD directly, JTAG_MOD, pull low or GND in the customer board, still not OK, right?

Please also readout the fuse map, and share it with me.

I will find time and try to borrow the validation board again, and test my previously secure JTAG chip again. In my previous testing, I even didn't meet issues when I totally follow the AN.

Best Regards,

kerry

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Tue, 29 Jun 2021 23:15:32 GMT

Thank you Kerry for the help,

Look, this is my map fuse.

I can't remember if I told you, but the only difference between my steps and what I did is that I incorrectly removed the resistor connected to JTAG_MOD, but I'm put GND manually to this pin.

Is there any way to know if this pin is ok with GND?. I tried to read JTAG_MOD and printing that but it showed me other error, something about TDI was always in HIGH, so I guess it was not a way.

Thanks for the help,

Vanessa

Re: Secure JTAG in imxrt1050-EVKB

vanessa_dis — Wed, 30 Jun 2021 23:23:39 GMT

Just to correct me for my previous repply, this was the output when I tried to read and print the values of JTAG_MOD (with an image)

also I would like to say that before doing this modification I had experimented some errors when I tried to erase my flash via J-LINK,

and reading I found that I had to unlock kinetis but it didn't work

Do you think this is like a kind of reason that connect with JTAG doesn't work? (even thought, this is rare because with SWD worked perfectly with this problem) Or do you thing that this is other independent problem?

I hope you know something about it, Thank you so much,

Vanessa

Re: Secure JTAG in imxrt1050-EVKB

kerryzhou — Thu, 01 Jul 2021 06:41:39 GMT

Hi @vanessa_dis

Manually control the JTAG_MOD to GND is no problem, in about two years ago, I also do it like that.

That's why I didn't mention it.

So, now, I will find a new RT1050 chip and do the testing again for you. And tell you step by step.

Please keep patient!

Best Regards,

Kerry