Microcomputer runaway monitoring device

摘要

The invention provides a control device for mutually monitoring two microcomputers at a low cost while reducing a parts number and doubly monitoring abnormality in each of the microcomputers. The control device transmits a reset signal to a main microcomputer and resets the main microcomputer when a frequency of a first pulse signal deviates from a normal frequency range determined by a frequency calculating means, in which the first pulse signal is output from the main microcomputer, and the frequency calculating means calculates a frequency of the first pulse signal by an input of the first pulse signal to a sub microcomputer. The control device transmits a reset signal to the sub microcomputer and resets the sub microcomputer when a frequency of a second pulse signal deflects from a normal frequency range, by an input of the second pulse signal to the main microcomputer from the sub microcomputer.

主权项

1. A microcomputer runaway monitoring device comprising:
a main microcomputer which is operated in a first operation cycle on the basis of a clock signal output from a first oscillating circuit; and a sub microcomputer which is operated in a second operation cycle on the basis of a clock signal output from a second oscillating circuit, wherein the microcomputer runaway monitoring device actuates the main microcomputer and the sub microcomputer in parallel, carries out a predetermined clocking processing by said main microcomputer and said sub microcomputer, transmits a reset signal to said main microcomputer via a first intermediate control circuit so as to reset the main microcomputer in the case that a frequency of a first pulse signal deviates from a frequency range which can be determined to be normal by a frequency calculating means, the first pulse signal being output from the clocking processing on the basis of said first operation cycle included in said main microcomputer and having a predetermined frequency, the frequency calculating means calculating the frequency of said first pulse signal by an input of the first pulse signal to the sub microcomputer, and transmits a reset signal to said sub microcomputer via a second intermediate control circuit so as to reset the sub microcomputer in the case that a frequency of a second pulse signal deviates from a frequency range which can be determined to be normal by a frequency calculating means, the second pulse signal being output from the clocking processing on the basis of said second operation cycle included in said sub microcomputer and having a predetermined frequency, the frequency calculating means calculating the frequency of said second pulse signal by an input of the second pulse signal to the main microcomputer.