SECURE-AWARE BUS SYSTEM

An integrated-circuit device includes a bus system, a plurality of master components, a plurality of slave components, and hardware filter logic. The bus system is configured to carry bus transactions and security-state signals for distinguishing between secure and non-secure transactions. The master components are switchable between a secure and a non-secure state. The hardware filter logic is configured to intercept bus transactions at an interception point, positioned within the bus system such that bus transactions from at least two of the master components and at least two slave components pass the interception point. It is also configured to use i) a slave address of the intercepted bus transaction, and ii) the security state of the intercepted bus transaction, to determine whether to allow the transaction, in accordance with a set of filtering rules, and to block intercepted bus transaction that are determined not to be allowed.