Depressing and then releasing pushbutton SW3 causes net PS_SRST_B to strobe Low. This reset is used to force a system reset. It can be tied or pulled High, and can be High during the PS supply power ramps. When the voltage at IN2 is below its threshold or EN2 (P.B. switch SW3 is pressed) goes Low, OUT2 (PS_SRST_B) goes Low.
Active-Low reset output RST_B asserts when any of the monitored voltages (IN_) falls below the respective threshold, any EN_ goes Low, or MR is asserted. RST_B remains asserted for the reset time-out period after all of the monitored voltages exceed their respective threshold, all EN_ are High, all OUT_ are High, and MR is deasserted. See the Zynq UltraScale+ Device Technical Reference Manual (UG1085) [Ref 3] for information on the resets.