The AXI Endpoint Protection Unit (EPU) LogiCORE™ IP core checks transactions on its subordinate interface, and either passes the transactions through to its manager interface, or blocks the transactions. In other words, it protects accesses to AXI subordinate endpoints implemented in the programming logic (PL). The AXI EPU IP uses a System Management Identifier (SMID) to provide addressing isolation between different managers and the Arm® TrustZone to separate secure (trusted) transactions from non-secure transactions.
Important: This document refers to the new AXI "manager" and
AXI "subordinate" inclusive terms to replace outmoded terms, as the latest version of the
Arm AMBA AXI and ACE Protocol Specification describes.