System on a chip with an arbitration unit to grant right of access to a common resource in response to conflicting requests for access from initiator modules, and storage key incorporating the arbitration unit

Abstract

An electronic system comprises a defined number N of functional modules, including a defined number P of initiator modules and a defined number Q of target modules, where N, P and Q are integer numbers such that 2≦P≦N and 1≦Q≦N. In the event of a plurality of conflicting requests to access a common resource originating from a plurality of respective initiator modules, an arbitration unit grants an exclusive right of access to the resource to a defined one of these initiator modules. The arbitration unit is constructed either to apply a standard arbitration mechanism to these respective initiators, or to apply as a priority a specific arbitration mechanism only to the members of a subset of these initiator modules, for each of which it receives a linked privileged access signal.