Electronic control unit
First Claim
1. An electronic control unit comprising:
- a program counter that indicates an address in a memory that stores an instruction to be executed;
an execution section that reads and executes the instruction stored in a storage area of the memory corresponding to the address indicated by the program counter;
a change section that changes, each time the execution section executes the instruction, the address of the memory indicated by the program counter to an address of the memory that stores an instruction to be executed next;
a storage control section that stores, in an expected value counter, an address of the memory that is indicated by the program counter when transitioning from a second process to a first process,the second process including a second instruction group having a plurality of second instructions to be performed successively while including at least (i) a jump to a subroutine or (ii) a conditional branch,the first process including a first instruction group having a plurality of first instructions that are successively executed and contain no branch instruction,the first instructions being stored respectively in storage areas of the memory according to an execution sequence while addresses of the memory corresponding respectively to the storage areas are varied in increments of a specified value according to the execution sequence;
an update section that changes the address of the memory stored in the expected value counter in increments of the specified value each time the execution section executes each of the first instructions after the transition to the first instruction group included in the first process;
a comparison section that compares the address of the memory indicated by the program counter with the address of the memory stored in the expected value counter; and
an error determination section that determines an error occurrence when a comparison result from the comparison section indicates a mismatch between the address of the memory indicated by the program counter and the address of the memory stored in the expected value counter.
1 Assignment
0 Petitions
Accused Products
Abstract
In an electronic control unit, an important process includes several instructions that are successively executed and contain no branch instruction. Each of the instructions is stored in each of storage areas of memory according to an execution sequence. The storage areas are respectively assigned addresses that vary in increments of a specified value according to the execution sequence. The important process stores, in an expected value counter, a value of a program counter when control transitions to the important process. If a comparison result indicates a difference between the value of the program counter and a value of the expected value counter, an occurrence of an error is determined.
26 Citations
7 Claims
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1. An electronic control unit comprising:
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a program counter that indicates an address in a memory that stores an instruction to be executed; an execution section that reads and executes the instruction stored in a storage area of the memory corresponding to the address indicated by the program counter; a change section that changes, each time the execution section executes the instruction, the address of the memory indicated by the program counter to an address of the memory that stores an instruction to be executed next; a storage control section that stores, in an expected value counter, an address of the memory that is indicated by the program counter when transitioning from a second process to a first process, the second process including a second instruction group having a plurality of second instructions to be performed successively while including at least (i) a jump to a subroutine or (ii) a conditional branch, the first process including a first instruction group having a plurality of first instructions that are successively executed and contain no branch instruction, the first instructions being stored respectively in storage areas of the memory according to an execution sequence while addresses of the memory corresponding respectively to the storage areas are varied in increments of a specified value according to the execution sequence; an update section that changes the address of the memory stored in the expected value counter in increments of the specified value each time the execution section executes each of the first instructions after the transition to the first instruction group included in the first process; a comparison section that compares the address of the memory indicated by the program counter with the address of the memory stored in the expected value counter; and an error determination section that determines an error occurrence when a comparison result from the comparison section indicates a mismatch between the address of the memory indicated by the program counter and the address of the memory stored in the expected value counter. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification