Access control for integrated circuit devices

A controller comprising:

• an output interface for causing performance of at least one control function;
• a memory including stored control instructions;
• a processor for executing the stored control instructions and operating the output interface in accordance therewith;
• and
• a security device governing access to at least a portion of the memory to be protected, the security device comprising:
• a plurality of switches connected to at least one control line of the memory to be protected;
• a plurality of input lines connected to data lines of the memory to be protected;
• and
• a lock unit connected to the switches, the lock unit comprising:
• a decision logic block for (i) detecting a command signal on the data line, (ii) detecting a permission code on the data line, (iii) upon validating the permission code detected on the data line, decoding the command signal and generating a lock/unlock state associated with the switches in response to the decoded signal, and (iv) during the decoding and lock/unlock-state generation, opening the switches to prevent access to the memory to be protected;
• a non-volatile memory for storing the lock/unlock state;
• and
• circuitry responsive to the non-volatile memory for operating the switches in accordance with the lock/unlock state.