Processing system, related integrated circuit and method

A method of operating a processing system, the method comprising:

• starting the processing system;
• reading a reference password from a non-volatile memory of the processing system;
• receiving, with a first configuration data client, configuration data read from the non-volatile memory, and providing, with the first configuration data client, the received configuration data to an associated first hardware block or first protection circuit, wherein the first hardware block or first protection circuit changes operation as a function of the configuration data;
• receiving, with a second configuration data client, configuration data read from the non-volatile memory and the reference password, and providing, with the second configuration data client, the received configuration data and the reference password to a temporary password repository of the processing system;
• storing the reference password in the temporary password repository;
• receiving a password verification command including a password from a processing unit of the processing system;
• obtaining the reference password from the temporary password repository;
• testing whether the password received and the reference password correspond;
• and
• when the password and the reference password correspond, transmitting an overwrite signal to a protection circuit of the processing system.

An integrated circuit comprising a processing system comprising:

• a non-volatile memory configured to store a plurality of reference passwords;
• a temporary password repository including a memory configured to store the reference passwords;
• a password upload circuit configured to read the reference passwords from the non-volatile memory and store the reference passwords in the temporary password repository;
• a password verification circuit configured to:
• receive a password verification command, from a first circuit, that includes a password and a slot number,
• obtain a reference password of the plurality of reference passwords from the temporary password repository based on the slot number,
• test whether the password received and the reference password correspond and produce a result based on the test, and
• when the result indicates that the password and the reference password correspond, generate an overwrite signal;
• a hardware block;
• a protection circuit coupled to the hardware block, wherein the protection circuit is configured to receive a control command from the first circuit and selectively forward the control command to the hardware block as a function of the overwrite signal,
• a first hardware block or first protection circuit, wherein the first hardware block or first protection circuit is configured to change operation as a function of configuration data, wherein the non-volatile memory is configured to store the configuration data, and wherein the reference passwords are stored together with the configuration data in the non-volatile memory;
• a first configuration data client associated with the first hardware block or first protection circuit, the first configuration data client configured to receive configuration data and provide the configuration data received to the associated first hardware block or first protection circuit;
• a hardware configuration module configured to read the configuration data from the non-volatile memory and transmit the configuration data read from the non-volatile memory to the first configuration data client;
• and
• a second configuration data client, the second configuration data client configured to receive configuration data from the hardware configuration module and provide the configuration data received to the temporary password repository, wherein when the hardware configuration module reads the configuration data from the non-volatile memory, the hardware configuration module transmits the reference password to the second configuration data client.