Time-based secure access control system

In a System on a Chip (SOC) having a plurality of master devices and a plurality of slave devices, wherein the master devices are in communication with the slave devices by way of a crossbar switch, a time-based access control system, comprising:

• a Central Access Control (CAC) circuit in communication with the plurality of master devices, wherein the CAC circuit manages requests for access to the slave devices by the master devices, and wherein when the CAC circuit receives an access request from a master device, the CAC circuit provides an acknowledgement of said access request back to the master device;
• a plurality of slave access control (SAC) circuits corresponding to the plurality of slave devices, wherein each slave device is coupled to a respective one of the SAC circuits, wherein each SAC circuit includes a dedicated timer and an access time control (ATC) circuit, and wherein each SAC circuit is in communication with the CAC circuit,
• wherein (i) a master device makes a time-based request for access to a slave device by issuing a time-based access request including a master device identification (ID), a slave device ID, and a requested access time, (ii) the CAC circuit receives the time-based access request and triggers the ATC circuit of the SAC circuit associated with the slave device identified by the slave device ID of the time-based access request to record an access request arrival time and the requested access time and to check whether a time generated by the dedicated timer of the ATC circuit slave device is less than a sum of the access request arrival time and the requested access time, and (iii) the SAC circuit allows or prevents transactions from the master device to the selected slave device based on the time check performed by the ATC circuit,
• wherein the CAC circuit controls the ATC circuits to limit access permissions of the master devices to the slave devices by checking whether the requested access time has expired.

A method of controlling access to a slave device by a master device in a time-based secure access control system, wherein the system includes a central access control (CAC) circuit and a slave access control (SAC) circuit, wherein the SAC circuit includes an access time control (ATC) circuit and a dedicated timer, the method comprising:

• generating a time-based access request including a requested access time by the master device for accessing the slave device;
• receiving and acknowledging the access request by the CAC circuit;
• and
• controlling the ATC circuit to limit the access permission to the slave device by checking whether the requested access time has expired.