8.4.4.2 Speculative Accesses

Speculative accesses reduce the latency introduced by the TZC and is the default behavior. When speculative accesses are enabled, the TZC forwards a transaction address to the client before verifying that the transaction is permitted.

If the transaction fails the security check, the TZC ensures that any read data, write data, and write enables are set to zero so that no data is visible and no write transaction occurs.

Note: Because the transaction address is not filtered in this mode, when processing secure applications, speculative accesses must be disabled.

To disable speculative accesses, see TZC_SYS_SPECULATION_CTRL and TZC_CPU_SPECULATION_CTRL.