Vehicle data abnormality determination device
View Patent ↗Disclosed is a vehicle data abnormality determination device including a storage unit for pre-storing a 2-byte remainder term which is a result of a CRC arithmetic operation on a target area for arithmetic operations in a predetermined memory area, and an arithmetic operation unit for performing a CRC arithmetic operation while including the 2-byte remainder term in this CRC arithmetic operation. Because when performing the CRC arithmetic operation, the vehicle data abnormality determination device performs the CRC arithmetic operation while including the 2-byte remainder term in this CRC arithmetic operation after performing an arithmetic operation on the target area, the vehicle data abnormality determination device always makes the computed result be zero when the data has not been falsified, and can detect whether or not the data has been falsified easily and properly.
1. A vehicle data abnormality determination device which determines an abnormality of data used for controlling a vehicle, said vehicle data abnormality determination device comprising:
a storage to pre-store a 2-byte remainder term which is a result of a Cyclic Redundancy Check (CRC) arithmetic operation on said data in a target area for arithmetic operations, in a predetermined memory area; and
a CRC arithmetic operator to perform CRC arithmetic operations on the data in the target area, and subsequently on the pre-stored 2-byte remainder term,
wherein when a flash ROM has a ROM capacity different from that of a mask ROM, a part of the flash ROM having a larger ROM capacity is excluded from a target for CRC arithmetic operations and the ROM capacity of said flash ROM is made to be equal to that of the mask ROM, thereby allowing the flash ROM to be switched to the mask ROM for obtaining a same CRC value for data stored in each corresponding block between the flash ROM and the mask ROM.
2. The vehicle data abnormality determination device according to claim 1 , wherein the arithmetic operator changes an arithmetic operation order to finally compute the 2-byte remainder term.
3. The vehicle data abnormality determination device according to claim 1 , wherein said CRC arithmetic operator carries out the CRC arithmetic operation on data stored in a ROM while carrying out normal control.
4. The vehicle data abnormality determination device according to claim 1 , wherein said CRC arithmetic operator carries out the CRC arithmetic operation by using a CRC-16 or CRC-Comité Consultatif Internationale Télégraphique et Téléphonique (CCITT).
5. The vehicle data abnormality determination device according to claim 1 , wherein said vehicle data abnormality determination device includes a Calibration Verification Number (CVN) arithmetic operator for further carrying out the CRC arithmetic operation on the CRC arithmetic result for each of a plurality of storage areas to compute the CVN.
6. The vehicle data abnormality determination device according to claim 5 , wherein said vehicle data abnormality determination device includes a communication controller to transmit the computed CVN, and transmits the CVN to an external tool via said communication controller.