Cant get i211 to be detected by PCIe interface

[KDobb]

Hi,

We have designed a QSeven module carrier board that has an unprogrammed/blank Intel I211AT on PCIe Lane 0. The I211 is not being detected.

Any ideas why?

The QSeven module uses an Intel Atom Bay Trail E3825 and provides:

- 1 Gigabit Ethernet interface (uses Intel I210)

- 4 PCIe interfaces

- 6 USB 2.0 interfaces

- An LPC Interface

- DisplayPort interface

Our carrier board implements the following high speed interface devices, all appear to work:

- Gigiabit Ethernet port which is directly driven by the QSeven module

- 2 Mini PCIe slots - using PCIe Lanes 1 & 2 and a USB interface each

- A Super I/O chip (Nuvoton W83627DHG-PT) - uses the LPC interface from the QSeven module

- A 2 lane DisplayPort interface

As far as we can tell . . .

- the I211 is connected correctly

- all pull-ups/pull-downs appear correct

- all voltages appear correct (3.3V, 1.5V, 0.9V)

- PCIe clock is present (cannot measure accurately as do not have a high bandwidth scope and high impedance probes, clock freg. is 100MHz though)

- An adapter card with another I211 on it works in the Mini PCIe slots

One other puzzling issue - the crystal connected to the I211 is not oscillating.

Is this normal or should the crystal operate even if the I211 is not detected?

The I211 is also not programmed (as can't communicate with it).

QSeven module is running Ubuntu but have also run in DOS and used Intel DOS tools to check for PCI devices.

I210 on QSeven module is detected in both Ubuntu and DOS.

Any ideas or suggestions appreciated?

Can Intel do a design review?

Board was designed in Altium.

Thanks.

[CarlosAM_INTEL]

Hello Herbie,

Thank you for contacting the Intel Embedded Community.

The information that may help you is stated on the answer to the question 2.24, on page 11 of the http://www.intel.com/content/dam/www/public/us/en/documents/faqs/ethernet-controller-i210-i211-faq.pdf Intel(R) Ethernet Controller I210/I211 Frequently Asked Questions.

On the other hand, in order to request an schematic review please follow the steps stated on the https://edc.intel.com/Tools/Design-Review/Default.aspx?language=en Design Review Services web site.

This service should be accessible to you if you have an Embedded Design Center (EDC) Privileged account. To request an upgrade from your Basic EDC account to a Privileged account, go to /www.intel.com/content/www/us/en/embedded/embedded-design-center-support.html http://www.intel.com/content/www/us/en/embedded/embedded-design-center-support.html and click on "Manage Your Intel Profile" found in the "Manage Your Account" section of the page. From there you can request an upgrade. After you submit the application, please let us know and we will expedite the review of your application. The application can be found at:

/www-ssl.intel.com/content/www/us/en/forms/intelligent-systems/registration-po.html https://www-ssl.intel.com/content/www/us/en/forms/intelligent-systems/registration-po.html

Please let us know if this information is useful.

Best Regards,

Carlos_A.

[KDobb]

Hi Carlos,

Thanks for the update.

I've requested my account be upgraded to a Privileged account.

Please note that my company has already signed an NDA for a colleague so he has a Privileged account. This was done around October 2014.

Can you use this NDA for my account?

Best regards,

Kieran

[CarlosAM_INTEL]

Hello Herbie,

Thanks for your reply.

We want to inform you that your EDC account has been updated.

Please let us know if the provided information is useful.

Best Regards,

Carlos_A.

[KDobb]

Hi Carlos,

Thanks, yes I received notification of my EDC account.

As per question 2.24 of the FAQs, our board has the iNVM security pin (pin 12) pulled down (usind 10k) by default so iNVM lock-out should be off.

I did try pulling this up on one board with now affect.

I don't see how this would affect detection of the i211 on the PCIe bus though.

Best regards,

Kieran

[KDobb]

Hi Carlos,

Below image shows DC voltages on pins of i211 I measured using a hand held DVM.

Are all these as expected? They seem correct to me except:

- PE_WAKE_N (pin 16): I measured it to be 0.228V whereas I was expecting this to be 3.3V.

- XTAL pins (45, 46): No oscillations observed when checked with a scope.

Regards,

Kieran

[Adolfo_S_Intel]

Hello Herbie

Please check the following documents that might be useful for your issue:

https://www-ssl.intel.com/content/www/us/en/embedded/products/networking/i210-at-i211-at-1g-base-t-reference-design-schematic.html Intel® Ethernet Controller I210-AT/I211-AT: Schematicshttps://www-ssl.intel.com/content/www/us/en/secure/embedded/nda/products/networking/gbe-i211-at-layout-review-checklist.html Intel® Ethernet Controller I211-AT: Layout Review Checklist

How many boards are you developing?

How many boards fail?

Have you tried swapping different components?

Best Regards,

Adolfo

[KDobb]

Hi Adolfo,

Thanks for your message.

We are developing one version of QSeven module carrier board that will be used as a data-logger in a 19" rack mount enclosure.

So far we have built 4 boards and all fail to detect the i211.

I have tried swap a known good chip from a Mini PCIe adapter onto one board but I don't think the soldering was very good. The chip is not being detected on this board.

When the circuit & PCB were being designed, I referenced the schematic and layout checklist you mentioned.

I actually used Rev. 2.3 of the checklist from the Networking Division. It seems to have the same content as the checklist you listed (Rev. 2.0 of LAN Access Division).

I mentioned before that the crystal is not operating. Is this normal for a blank device or does it indicate a fault?

I will see if I can submit the design to the Design Review Service as I suspect there may be a PCB issue.

Is there a reference PCB layout for the i211?

Best regards.

[Adolfo_S_Intel]

Hello Herbie

I searched our documentation but didn't found any layout template.

You can try our Design Review Services on the following page: https://edc.intel.com/Tools/Design-Review/Default.aspx?language=en https://edc.intel.com/Tools/Design-Review/Default.aspx?language=en

Also one of our engineers provided the following feedback regarding your case:

With the PE_WAKE_N being 0.2V, this indicates that the chip is not being released from reset. The system should also not be shutting down if this is the case, as the WAKE line is always active.

I hope this information is useful for you,

Best Regards,

Adolfo Sanchez

[KDobb · Accepted solution]

Hi Adolfo,

We believe we have found the problem as to why the i211 was not being detected on the PCI bus.

As mentioned earlier, the 25MHz crystal was not oscillating.

Replacing the crystal (with a different brand and package) now produces oscillations and now allows the i211 to be detected on the PCI bus.

Thus, the crystal appears to be the problem.

We have now 3 boards working after replacing the crystals.

I'd like to find out why the original crystals did not work.

The original crystals were Abracon ABM8G-25.000MHZ-18-D2Y-T (25MHz, 18pF Load capacitance, +-20ppm).

These are 3.2mm x 2.5mm with 4 corner pads.

We replaced these with NDK NX5032GA-25.000000MHZ-LN-CD-1 (25MHz, 8pF Load Capacitance, +/-50ppm).

This is a physically larger part, 3.2mm x 5.0mm, with 2 end pads.

The circuit uses 27pF COG load caps as recommended and these values match the crystal load cap. specification.

So why did the original Abracon crystals not work?

Best regards.

[KDobb]

Hi Adolfo,

I contacted the manufacturer of the crystal we used to determine why it did not work.

They suggested using lower value load caps (22pF instead of 27pF).

They based this on assuming a stray capacitance of 2pF

I have since tested with no caps, 10pF, 20pF and 22pF load caps and in all cases the crystal now works.

Best regards.

[Adolfo_S_Intel]

Hello Herbie

I'm glad your issue was solved.

And thanks for providing feedback that can be useful to other members of this community.

Best Regards,

Adolfo Sanchez.