Microprogrammable device code signature

A non-transitory medium bearing instructions that, when executed by a microprogrammable electronic device, cause the microprogrammable electronic device to perform operations comprising:

• operating according to instruction cycles, each instruction cycle divided into a respective first and a respective second operating phase;
• reading a first instruction from a code memory storing a code at the first operating phase of an instruction cycle;
• decoding and executing the read first instruction at the second operating phase of the instruction cycle;
• reading a second instruction from the code memory at the second operating phase of the instruction cycle concurrently with the microprogrammable electronic device decoding and executing the first read instruction, the second operating phase having a length equal to a length of the first operating phase;
• computing a signature of the code on the basis of the read second instruction;
• and
• detecting a corruption of the code stored in the code memory on the basis of the computed signature differing from a reference signature.

A method, comprising:

• operating according to instruction cycles, each instruction cycle divided into a respective first and a respective second operating phase;
• reading a first instruction from a code memory storing a code at the first operating phase of an instruction cycle;
• decoding and executing the read first instruction at the second operating phase of the instruction cycle;
• reading a second instruction from the code memory at the second operating phase of the instruction cycle concurrently with decoding and executing the first read instruction, the second operating phase having a length equal to a length of the first operating phase;
• computing a signature of the code on the basis of the read second instruction;
• and
• detecting a corruption of the code stored in the code memory on the basis of the computed signature differing from a reference signature.