Intel® Stratix® 10 Hard Processor System Technical Reference Manual

ID 683222
Date 11/28/2022
Public

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4.7.5. Secure and Non-secure Transactions

The programming model for secure and non-secure transactions for the system interconnect firewalls and CCU differ.

When you configure the system interconnect firewall to permit secure (S) transactions, only secure transactions traverse the firewall. When you configure the system interconnect to permit non-secure (NS) transactions, both secure (S) and non-secure (NS) transactions traverse the firewall.

However, the CCU behaves different with respect to the filtering functions it provides. If you configure the CCU to permit S transactions, only S transactions traverse the CCU (similar to the system interconnect firewall). However, if you configure the CCU to permit NS transactions, only NS transactions pass through to the slave. The CCU blocks S transactions in this case. You can configure CCU filtering to allow both S and NS transactions to traverse the CCU similar to the system interconnect firewall by programming the following values to the NS bit in the *am_adbase* and *am_admask* registers:

Table 50.  CCU Secure/Non-Secure Transaction Configuration *am_adbase* and *am_admask* registers exist for each master to slave bridge within the CCU.
*am_adbase*.ns *am_admask*.ns Outcome
0 (secure) 1 (enabled) Secure transactions pass; non-secure transactions generate an error
0 (secure) 0 (disabled) Secure and non-secure transactions pass