The conceptual current monitoring circuit and architecture shown in the following diagram can be used for self-monitoring of the SEL conditions in a Zynq UltraScale+ device. An external current sense amplifier can feed into dedicated VP/VN analog monitor pins that are directly wired into the PL SYSMON ADC. It is used with a customized code base for the PMU to monitor for the current step and other SEL conditions. The PMU code base for SEL monitoring, which accounts for the previous guidance, makes this type of self-monitoring solution viable. An alternative approach of running SEL monitoring code in the RPU or APU, rather than the PMU, also can be viable.
Leveraging the additionally supported LVAUX mode in XQ ruggedized devices, the SEL rate on HP I/O auxiliary blocks is eliminated. LVAUX mode eliminates the need for monitoring SEL on the VCCAUX_IO power supply, significantly reducing the device SEL rate and removing any long-term reliability concern that can result from SEL. When LVAUX mode is implemented, the PS and PL SYSMON blocks are the only remaining SEL susceptible elements in the device. This document provides guidance on how to configure the device to operate in LVAUX mode.