Control apparatus and method having program rewriting function

A program rewriting method for an electronic control unit comprising:

• connecting a rewriting tool to the electronic control unit which stores a program therein;
• transmitting a first code from a transponder to the electronic control unit;
• checking for, within the electronic control unit, an agreement between the first code and a second code stored in the electronic control unit;
• transmitting a third code from the rewriting tool to the electronic control unit;
• checking for, within the electronic control unit, an agreement between the third code and a fourth code stored in the electronic control unit;
• transmitting a new program from the rewriting tool to the electronic control unit, when check results of the checking steps are in predetermined relations, respectively;
• and
• rewriting the stored program by the new program.

An electronic control apparatus comprising:

• a first non-volatile memory storing an attestation reference data of a key;
• a second non-volatile memory storing a control content required for controlling a control object, the second memory being capable of rewriting the control content in response to a predetermined operation of the key and an external rewriting command;
• retrieving means for retrieving an attestation data of the key;
• checking means for checking for an agreement between the retrieved attestation data and the stored reference data;
• and
• disabling means for disabling rewriting of the control content stored in the second non-volatile memory, when a check result of the checking means indicates a disagreement between the retrieved attestation data and the stored reference data.

An electronic control apparatus comprising:

• a non-volatile memory storing a program and an attestation data of the stored program, and capable of rewriting the stored program;
• retrieving means for retrieving from an external device an attestation data of a new program to be written over the stored program;
• checking means for checking for an agreement between the retrieved attestation data of the new program and the stored identification data;
• and
• disabling means for disabling rewriting of the new program into the non-volatile memory, when a check result of the checking means indicates a disagreement between the retrieved attestation data and the stored attestation data.

An electronic control apparatus comprising:

• a memory having a first storage area for storing an attestation data, and a second storage area for storing a control content required for controlling a control object and capable of rewriting the control content;
• input means for inputting a code data transmitted from an external transponder;
• checking means for checking for an agreement between the transmitted code data and the stored attestation data;
• and
• rewriting means for rewriting the control content in the second storage area in response to a check result of the checking means.