Termination of secure execution mode in a microprocessor providing for execution of secure code

A microprocessor apparatus, for executing secure code within a secure execution environment, the microprocessor apparatus comprising:

• a secure non-volatile memory, configured to store a secure application program;
• and
• a microprocessor, coupled to said secure non-volatile memory via a private bus, configured to execute non-secure application programs and said secure application program, said microprocessor comprising:
• secure execution mode logic, configured to detect execution of a secure execution mode return event, and configured to terminate a secure execution mode within said microprocessor, wherein said secure execution mode exclusively supports execution of said secure application program.

A method for executing secure code within a secure execution environment, the method comprising:

• providing a secure non-volatile memory for storage of the secure code, wherein the secure code is to be stored within the secure non-volatile memory via private transactions accomplished over a private bus that is coupled to the secure non-volatile memory;
• and
• terminating a secure execution mode within a microprocessor, wherein the secure execution mode exclusively provides for execution of the secure code, said terminating comprising:
• detecting execution of a secure execution mode return event;
• wherein the private bus is isolated from all system bus resources within the microprocessor and external to the microprocessor, and wherein the private bus is observable and accessible exclusively by secure execution logic within the microprocessor.