Disabling FPD in Boot Sequence - 2021.2 English

Zynq UltraScale+ MPSoC Software Developer Guide

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2021.2 English
Perform the following to avoid an FPD lockout, where FPD Power is applied momentarily:
  • Apply the power until the completion of bootROM execution.
  • To power down the FP during FSBL execution, set FPD bit '22' of PMU_GLOBAL REQ_PWRDWN_STATUS register.
  • To bring the FP domain up in a later stage of the boot process, set the PMU_GLOBAL REQ_PWRUP_STATUS bit to '22’.

Perform the following in cases where the FPD power is not applied before the FSBL boots

  1. Power up the R5.
  2. A register is set indicating the FPD is locked pending POR as the reset or clear sequence cannot execute on the FPD.
  3. R5 can read the FP locked status from PMU_GLOBAL REQ_ISO_STATUS register bit ‘4’.
  4. At this stage, PMU_GLOBAL REQ_PWRUP_STATUS bit '22' will not be set.
  5. To bring the FPD node back up, power must be supplied to the node and a POR needs to be issued.