Ethernet Test fail by TX2

When we test the Gigabit network with your development board, we found that the test mode2 was fail. It means that the jitter is too large.As shown below, is there any problem with the circuit?Because this test was both fail on your development board and the extended board designed by us.

Hi, can you please tell the detail test procedure? How many modules did you test? Basically the dev kit is validated before ship out, should have no such failure.

Hi Trumany:

We use mdio interface to write BRM89610 register.
We write register 09h bit 15:13 and register 00h bit 12 to go to test mode.
please refer to the attached files.

MCS89610-DS02-RDS_decrypted.pdf (1.66 MB)

You need to ask vendor for tuning method, they will give you the guide of what/how to change the value of registers.

Hi Trumany:

We are just doing gigabyte network Signal Integrity test, we can let network phy goto compliance test mode, but the test result is fail. We also test TX2 devkit, the gigabyte network Signal Integrity test is also fail. I want to check with you, does TX2 devkit pass the gigabyte network Signal Integrity test? Can you tell the detail gigabyte network Signal Integrity test procedure?

We write a linux program by control mdio interface to set the BRM89610 register value, and then it go to test mode. You have done the same procedure?

Dev kit platform is surely validated. Did you get the guide from vendor? Regarding this kind of third-part device test, first you need to get the correct guide from vendor, if still fail, better to do cross test with other dev kit (if have) to eliminate the possible single board issue, if it is board issue then run RMA process. Currently we have no more other info about this can be shared.

Hi guohoujin2006, did you try disabling Auto-MDIX ?

Hi Trumany:

Auto-MDIX is set at register 18h, Auto-MDIX is default disabled, and we read register 18h is 0x400 at default, so the Auto-MDIX is disabled.

Hi Trumany:
Could you offer the report of a Gigabit test including 4 test modes to us

As I said, the ethernet tests is surely validated, you just need to check the test setup carefully, especially on if any loose connection on the probing point?

But when we test your dev kit ,it also failed.So I want to see the report you have tested before.

The report is not public, please check your test setup.

What’s the value of 18h(Shadow 111)? The Force Auto-MDIX Mode control is bit 9 of 18h (Shadow 111).


We are working on a design based on the development kit. You made the following statement which is ambiguous and does not directly provide an answer to the question.

Your Quote:
“As I said, the ethernet tests is surely validated, you just need to check the test setup carefully, especially on if any loose connection on the probing point?”

Has the design of the evaluation kit been validated or not? You used the word “surely” which means that you are not certain whether or not the module and development kit have been tested and were successfully validated. Has the Ethernet on the development kit been tested and passed all industry standard tests? Please don’t be so vague. The answer is either that the dev kit has been validated or not. Was it tested and did it pass ALL tests? Yes or No answers to both questions, not surely!

This is pretty important for those deploying products based on the development kit or even the TX2 module. Since the carrier of the development kit only contains the transformers and connector, it is likely that any jitter related failures are caused by the module itself. If the design has not been validated, this test failure could indicate that the TX2 module itself has an major flaw. Please clearly state that this interface was tested to accepted industry IEEE standards and passed all tests. This isn’t something to be vague about and the fact that the report is not public as you state doesn’t add any confidence.

Thank you!