The XMPU is configurable either one time or through a secure source. At boot time, the XMPU can be configured and its configuration is locked. If an XMPU register set is locked, the XMPU can only be reconfigured after the next power-on reset (POR). If the configuration is not locked, the XMPU can be reconfigured any number of times by trusted software (using a secure source).
Recommended:
Xilinx recommends only configuring each XMPU one time.
When an XMPU is programmed, all of its settings must be programmed to ensure that only
the allowed transactions go through.