Patent ID: 8479022

Claim:
A method of operating a digital system including a graphics display and secure computing resources, comprising the steps of: in a non-secure mode, preventing access to the secure computing resources; executing an application program; displaying results of the executing step on the graphics display; entering into a secure mode of operation for executing a secure portion of the application program by: jumping to an entry address at a particular address in an instruction memory; executing an activation sequence of instructions beginning at the entry address; and monitoring the activation sequence of instructions independently of the executing and entering the secure mode of operation only if the activation sequence of instructions is fully executed by the CPU in a pre-defined order; then unlocking access to the secure computing resources; and executing the secure portion of the application program using the secure computing resources, including activating a secure mode indicator that is independent from the graphics display; wherein the secure mode indicator can only be activated by the trusted program code while in the secure mode of operation.