PLTRST signal never deasserts on boot

[PVarl]

I'm using the X-Powers PMIC and the Cherry Trail T3 package. On power up, all the core processor rails come up correctly; CORE_PWROK and VCCA_PWROK both go high; but the Cherry Trail never deasserts PLTRST# . This is preventing the system from fully booting. I haven't been able to find shorts in the board that might be causing the problem, and I've been through several reference designs and I think I'm matching them as closely as I can, but I still haven't been able to figure out what's wrong. To me it looks like the PMIC is working but something is going wrong on the Atom side. The datasheet states that PLTRST# should desassert when CORE_PWROK is stable and PMC_RSMRST is deasserted; when I scope CORE_PWROK it looks stable for 500ms before the PMIC resets, and PMC_RSTRST is deasserted stably. Is there another requirement for PLTRST# deasserting that I'm missing?

[CarlosAM_INTEL]

Hello Pauline

Thank you for contacting Intel Embedded Community.

In order to help you please address your questions to the https://www-ssl.intel.com/content/www/us/en/forms/design-assistance.html Embedded Design Assistance, where you be connected with a representative in your area, which could possibly help with your project. Because unfortunately the Atom x5 and x7 (formerly Cherry Trail), which are part of the Bay Trail -T family that is on the "off-roadmap" and its support is for limited manufacturers. For this reason, these processors are unsupported through this channel. Click on http://ark.intel.com/products/codename/46629/Cherry-Trail this link to learn more about the specifications of the cited Atom devices.

Best Regards,

Carlos_A.

[KChen86]

Hi Pauline,

Did you find the answer to this issue? I have same issue in Braswell platform, the PLTRST# never desserts after PWROK asserted.

Best Regards,

Kevin

[CarlosAM_INTEL]

Hello KevinChen29,

Thank you for contacting Intel Embedded Community.

In order to better understand your communication, could you please confirm that problem is the same that you have consulted through the Carlos_A.

[JLian12]

@Hi Pauline,

You can check all of the power of CPU correct or not first and then measure the power sequence.

I had this issue before and found there's one power not connect to CPU cause PLTRST# not high

although COREPWROK is high.