Integrated circuit with secure scan enable

An integrated circuit senses attempts to access security-related data stored in registers connectable into a scan chain when the attempt includes locally and selectively asserting a scan-enable signal at a corresponding branch of the scan-enable tree when the integrated circuit is in a secure functional mode. When such an attempt is detected, the integrated circuit (i) generates a security warning that causes a reset of the security-related data and/or (ii) engages a bypass switch to disconnect the scan chain from the respective output terminal to preclude the security-related data from being shifted out of the IC via the scan chain.