5.5 Security and DT enable

The CCN-502 includes two signals that provide Secure access to the debug, trace, and PMU capabilities.

These signals are:

NIDENA global enable for all debug, trace, and PMU functionality. This overrides all other software enable controls.
SPNIDENA global enable for Secure debug, trace, and PMU. It is only applicable when NIDEN is asserted.

Deasserting SPNIDEN prevents Secure event counting wherever possible. Where a performance event cannot be determined to be Secure or Non-secure, that event is considered as Secure.


The secure_debug_disable bit of the MN secure_access register is used to override the SPNIDEN filtering. When secure_debug_disable is 0, which means Secure debug disable is off, all events, both Secure and Non-secure, are counted by the PMU. The default value of secure_debug_disable is 0.
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