Peripheral Access Control via Filter Registers

The patent introduces an access control mechanism as an intermediary component between peripheral devices. This mechanism includes filter registers that store access control rules and a comparison unit that evaluates transaction attributes against these rules. The intermediary blocks unauthorized peer-to-peer transactions while allowing legitimate communication, thus maintaining security without completely disabling efficient direct communication between devices.

The access control mechanism is segmented into distinct functional components: filter registers for storing access rules, a comparison unit for evaluating transactions, and integration points within the peripheral device architecture. This segmentation allows the security function to be added modularly without redesigning the entire communication system, enabling selective control over different transaction types and address ranges.

The patent extracts the access control function from the host device and relocates it to the peripheral devices themselves. By implementing filter registers and comparison units within or near the peripheral devices, the system eliminates the need to route transactions through the host for security checking. This extraction reduces communication latency and host processing overhead while maintaining security control.

The peripheral devices are empowered to perform their own access control checks through integrated filter registers and comparison units. Each peripheral device can independently evaluate incoming transactions against its configured access rules without requiring host device intervention. This self-service approach reduces dependency on the host, lowering latency and power consumption while maintaining security.