4 Replies Latest reply on Dec 14, 2017 5:31 PM by JackLiang

    PLTRST signal never deasserts on boot

    Pauline Community Member

      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?