Vehicle data abnormality determination device
First Claim
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.
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Accused Products
Abstract
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.
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Citations
6 Claims
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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:
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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. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification