The FPD-reset resets all of the FPD power domain and can be triggered by errors or a software register write. If the FPD reset is due to error signal, then the error must be indicated to both the LPD and the PL.
The FPD reset can be implemented by leveraging the FPD power-up sequence; however, it needs to gracefully terminate FPD ingress and egress AXI transactions before initiating reset of FPD. FPD reset sequence can be PL Reset.
The Zynq UltraScale+ MPSoCs has general-purpose output pins from the PMU block that can be used to reset the blocks in PL. Additionally, GPIO using the EMIO interface can also be used to reset PL logic blocks. For a detailed description of the reset flow, see the this link to the “Reset System” chapter in the Zynq UltraScale+ Device Technical Reference Manual (UG1085).
For more information on the software APIs for reset, see the PMU firmware in Platform Management.