2.3. Constraints of use

The TZASC has the following considerations relating to change in programmers view on an active system:

An example of this can be an LCD controller dealing with a frame buffer that is switching between a Normal world and Secure world use.


There is no direct mechanism to ascertain if there are any outstanding AXI transactions, and so the designer must use their system knowledge to apply reasonable mechanisms.

It is recommended that any DECERR, or TZASC interrupt handler is designed to expect, and potentially ignore events generated under these circumstances.

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