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?
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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.