Debug architecture

Roughly described, a method of restricting access of a debug controller to debug architecture on an integrated circuit chip, the debug architecture comprising an access controller, a plurality of peripheral circuits, and a shared hub, the shared hub being accessible by the access controller and the plurality of peripheral circuits, the method comprising: at the access controller, authenticating the debug controller; at the access controller, following authentication, assigning to the debug controller a set of access rights, the set of access rights granting the debug controller partial access to the debug architecture; and after assigning the set of access rights, allowing the debug controller access to the debug architecture as allowed by the set of access rights.