JTAG test issue on Vybrid MVF50NS151CMK40

[luc410]

Hello,

I made a boundaryscan project for a board with a Vybrid module MVF50NS151CMK40 using the "Cascon" tools from Göpel electronic.
I have a bad answer when I read the ID register:
Cascon tools reads 0100 1011101000000000 01000111011 1 (4BA00477).
Value expected (see BSDL): 0001 1001100000000000 00000001110 1 (1A80001D).
The value reads (4BA00477) is the "debug ID code from the JTAG DP port" (see sheet 1286 of the VFXXX controller reference manual).
So, I understand that the Vybrid is in debug mode, not in test mode (JTAG 1149.1).
In the BSDL (VYBRID_364_F.bsdl), there is no compliant pattern or design warning.
Is there a special configuration to work with the "test" tap port, based on IEEE1149.1 specification ?

Regard.

Luc

[sinanakman]

Hi Luc

The picture is too small for me to see the details but you mention :

"-Load IR (Instruction Register) with IDCODE opcode."

According to Table 9-19 in Reference Manual the IDCODE for

JTAGC should 4'b0000 (as opposed to 4'b1110 for ARM DAP).

Perhaps you can verify what IDCODE is being sent by the tool

are using.

Hope this helps.

Regards

Sinan Akman

[luc410]

Hi Sinan,

The IDCODE "opcode" sent by the tool is 4'b0000, the tool use informations from the bsdl file.
Sorry for the picture, I put a new one:

I don't understand why I am in the ARM DAP, I should be in the JTAG TAP : perhaps a bad hardware configuration, but I did not find

any information on this subject.

Thanks for your help.

Luc

[sinanakman]

Hi Luc

On my TWRVF65GS10 board I have no problem reading both idcodes :

JTAG>wir 4 00
JTAG>rdr 32  
1980101d
JTAG>wir 4 0e
JTAG>rdr 32  
4ba00477

Are you able to send out IDCODE instruction manually to your board ?

Your SoC is slightly different than mine but it should work the same

way. Perhaps you can contact to your test vendor and see if this a bug in

their software.

If you prefer you can capture your JTAG lines using a logic analyzer from

start until you see the problem and send my way. I can then take a look

and probably see what's going on.

Regards

Sinan Akman

[luc410]

Hi Sinan,

Thank you for the time spent answering me.

The goal of this test is not only to check the IDCODE, but to communicate with the
boudary scan register to read/write external I/O (not  chek internal functions of the SOC).
Checking the ID code validates the jtag chain (the right component in the right place) and after the testor go to the next step who is "interconnections test" to chek connections between boundary scan devices.
I did this test, and I got anything as a result.
My understanding is that I am not communicating with the right jtag chain, but I do not understand why.
Normally, if the component complies with standard 1149.1, the IDCODE register of the bsdl should be accessible through the jtag bus, without the need to write in the instruction register (see below):

if the component is not in phase with this procedure, this must be specified in the bsdl (compliant pattern or design warning), but, at this time, I don't find these informations.
I do not have a logic analyzer, but I think it is possible to visualize with the tester the TCK / TMS / TDI / TDO signals. I will send you the captures if it works.

Thanks for your help.

Luc

[luc410]

Hi Sinan,

Using the analyzer of the tool,I realized that the tester came directly to read the IDCODE without sending the instruction before: it is an error on my part, it is possible to preload the instruction register before reading the IDCODE. I made the correction and it's now ok. I apologize for the inconvenience.
Many thanks for your help.

Luc

[sinanakman]

Bonjour Luc

I am very happy to hear that you resolved the issue. The idcode is also available in the data register right after when the TAP is reset. But in your case Vybrid is a bit unusual in that the DAP and JTAGC are sharing the same instruction register and it seems out of reset it is returning the idcode of DAP. By retrieving the idcode explicitly now using the IDCODE your test software seems to be working well.

Happy to hear you can continue your projects. If you have any other questions related to JTAG particularly for NXP SoCs please don't hesitate to ping me either directly or via this forum here.

Best regards

Sinan Akman

[luc410]

Hi Sinan,

I keep developing the test program and it seems that the Vybrid I/O are not driveable.
The output remain in hight impedance  state even if I try to drive a 0 with the EXTEST instruction.

I found in another thread a document "BSDL_errata", but I would like to be sure that this errata applies to the component
use by the customer.
Do you know if I can fin a "more official" information on NXP Website about this issue ?

Many thanks for your help.

Luc

[sinanakman]

Hi Luc

Sorry for the late reply. The only documents I have access on Vybrid SoCs are the documents that are on the web. I believe at one point NXP granted Timesys the support for Vybrid SoCs. Perhaps you can ask them if they have an official errata on BSDL. Likewise Yuri might be able to send you any known official errata of this SoC.

Are you having difficulty driving a set of pins or only a particular one ?

Regards

Sinan Akman

[luc410]

Hi Yuri,

I already read this thread : this is not the same issue, in my case I can't read the "good" ID-CODE in infrastucture test.
I wan't to read this ID-CODE (extract from  "VYBRID_364_F.bsdl" file):

    
In fact I read this one (extract from "VFXXXRM.pdf" VFXXX Controller Reference Manual):

Regards.

Luc

[Yuri]

luc410 

Hello,

  is it possible to look at JTAG tool log ?

Regards,

Yuri.

[luc410]

Hi Yuri,

Here is the log:

‍

There are two jtag chain, one with U0 + U6, and another with U12 (Vybrid).

U12 power are controlled by U0+U6, so the sequence is the follow:

Test infrastructure U0+U6.
Turn on Vybrid power (U0+U6).
Test infrastructure all (U0+U6 on chain 1, U12 on chain 2).

For the infrastructure test, for the three devices, the process is alway the same.
-Load IR (Instruction Register) with IDCODE opcode.
-Scan IDCODE register (32 bits) and compare with the IDCODE of the bsdl file.

The IDCODE is ok for U0 and U6, but fail on U12 (Vybrid).

Thanks for your help.

Luc

[Yuri]

Hello,

  According to the following Community thread, it contains workable BSDL.

https://community.nxp.com/thread/309613 

Regards,

Yuri.