ON-VEHICLE CONTROLLER

摘要

PURPOSE:To provide the on-vehicle controller by which the writing of data in an E<2>PROM can be exactly ensured, in the controller equipped with the E<2>PROM. CONSTITUTION:A normal power source is supplied from a power source 12 through a main switch 13 to a power source circuit 14 for control, and the power source 12 is directly connected with the backup power source terminal Batt of the power source circuit 14 for control. The normal power source Vc of the power source circuit 14 for control is supplied to the power source input terminal Vcc of an E<2>PROM 16 subordinately connected with a microcomputer 15. The E<2>PROM 16 has/(BUSY) terminal which outputs a signal indicating that the data are being written, and conducts and sets a transistor 18 while the data are being written. The power source VSTB for backup of the power source circuit 14 for control is supplied to the transistor 18, and the power source VSTB is supplied through this transistor 18 to the Vcc as a power source for writing.