The SmartConnect combines multiple PS Master I/Fs into a single or multiple XMPU_PLs, as evidenced from the following figure. Use SmartConnect instead of AXI-Interconnect to maintain access to PS MasterIDs.
Figure 1. Connecting Multiple PS Masters I/Fs
Note: The XMPU_PL will not provide any AXI data width conversion. Use SmartConnect upstream, and/or AXI-Interconnect downstream, to provide any needed data or clock conversions between the PS Master and end-point PL-Slaves.