초록 ▼

A vehicle-onboard control system for controlling various devices mounted on the motor vehicle. A control program for the control system can be altered through facilitated processing procedure with simple hardware structure while avoiding unfitness of control variables stored in a backup random acces

A vehicle-onboard control system for controlling various devices mounted on the motor vehicle. A control program for the control system can be altered through facilitated processing procedure with simple hardware structure while avoiding unfitness of control variables stored in a backup random access memory and used in executing the control program. A bootstrap program (13) responds to a command signal (C) issued by an external memory rewriting device (50) upon rewriting of the control program to thereby set an initialization flag (FN) in a backup RAM (14) containing control variables. The control program rewritten with updated data supplied from the memory rewriting device (50) responds to the set state of the initialization flag (FN) upon activation, to thereby initialize the control variables stored in the backup RAM (14) so that the control variables conform with the control program.

대표청구항 ▼

[ What is claimed is:] [1.] A vehicle-onboard control system installed on a motor vehicle for controlling at least one device mounted on said vehicle, comprising:a central processing unit (11) for executing a control program by using various control variables to thereby control said device (40) moun

[ What is claimed is:] [1.] A vehicle-onboard control system installed on a motor vehicle for controlling at least one device mounted on said vehicle, comprising:a central processing unit (11) for executing a control program by using various control variables to thereby control said device (40) mounted on said motor vehicle;a writable non-volatile read-only memory (12) for storing said control program;a backup random access memory (14) for storing said control variables;a backup power supply (30) for supplying electric power to said backup random access memory (14);a bootstrap program (13) for operating said central processing unit (11) to allow said control program to be rewritten;an address changing interface (15) for locating said bootstrap program (13) at an address executable by said central processing unit (11) upon rewriting of said control program; anda memory rewriting device (50) for outputting a rewrite signal (A) for actuating said address changing interface (15) and a command signal (C) for activating said bootstrap program (13);wherein an initialization flag (FN) is provided in said backup random access memory 14) adapted to be set by said bootstrap program (13) in response to said command signal (C) upon rewriting of the said control program; andwherein said control program responds to the set state of said initialization flag (FN) upon activation of said control program after having been rewritten, to thereby initialize said control variables stored in said backup random access memory (14).