Control apparatus for automobile engine including microcomputer which may be programmed after mounting on a circuit board

A control apparatus for controlling an internal combustion engine of an automobile, said control apparatus comprising:

• a circuit board having a plurality of input terminals and a plurality of output terminals;
• a microcomputer mounted on said circuit board and having an input and an output, said input adapted for connection via a first one of said input terminals to a sensor, external to said circuit board, which senses an operating condition of the automobile, said output adapted for connection via one of said output terminals to an actuator, external to said circuit board, for controlling an operating condition of said internal combustion engine in accordance with the sensed operation condition;
• program memory means in said microcomputer for storing a control program to control said microcomputer;
• write control means surface mounted on said circuit board and responsive to a write control signal for controlling said program memory means to permit writing of the control program into said program memory means;
• input means surface mounted on said circuit board and connected to a second one of said input terminals for receiving from a source, external to said circuit board, the control program to be written into said program memory means when said program memory means is under control of said write control means;
• and
• isolation means mounted on said circuit board, connected to said microcomputer, to said first one of said input terminals, and to said one of said output terminals, and responsive to the write control signal, for electrically isolating said microcomputer from the sensor and the actuator when said write control means is controlling said program memory means, to inhibit input of signals from the sensor and output of signals to the actuator during writing of the control program into said program memory means.

A control apparatus for controlling an internal combustion engine of an automobile, said control apparatus comprising:

• a circuit board having a plurality of input terminals and a plurality of output terminals;
• a single chip microcomputer sealed in plastic, surface mounted on said circuit board, and having an input and an output, said input adapted for connection via a first one of said input terminals to a sensor, external to said circuit board, which senses an operating condition of the automobile, said output adapted for connection via one of said output terminals to an actuator, external to said circuit board, for controlling an operating condition of said internal combustion engine in accordance with the sensed operating condition;
• program memory means in said microcomputer for storing a control program to control said microcomputer;
• write control means surface mounted on said circuit board and responsive to a write control signal for controlling said program memory means to permit writing of the control program into said program memory means;
• input means surface mounted on said circuit board and connected to a second one of said input terminals for receiving from a source, external to said circuit board, the control program to be written into said program memory means when said program memory means is under control of said write control means;
• and
• isolation means mounted on said circuit board, connected to said microcomputer, to said first one of said input terminals and to said one of said output terminals, and responsive to the write control signal, for electrically isolating said microcomputer from the sensor and the actuator when said write control means is controlling said program memory means, to inhibit input of signals from the sensor and output of signals to the actuator during writing of the control program into said program memory means.

A control apparatus for controlling an internal combustion engine of an automobile, said control apparatus comprising:

• a circuit board having a plurality of input terminals and a plurality of output terminals;
• a single chip microcomputer sealed in plastic, surface mounted on said circuit board, and having an input and an output, said input adapted for connection via a first one of said input terminals to a sensor, external to said circuit board, which senses an operating condition of the automobile, said output adapted for connection via one of said output terminals to an actuator, external to said circuit board, for controlling an operating condition of said internal combustion engine in accordance with the sensed operating condition;
• program memory means in said microcomputer for storing a control program to control said microcomputer;
• write control means surface mounted on said circuit board and responsive to a write control signal from said microcomputer, for controlling said program memory means to permit writing of the control program into said program memory means;
• first input means surface mounted on said circuit board and connected to a second one of said input terminals for serially receiving from a source, external to said circuit board, a control program to be written into said program memory means when said program memory means is under control of said write control means;
• isolation means mounted on said circuit board, connected to said microcomputer, to said first one of said input terminals, and to said one of said output terminals, and responsive to the write control signal, for electrically isolating said microcomputer from the sensor and the actuator when said write control means is controlling said program memory means, to inhibit input of signals from the sensor and output of signals to the actuator during writing of the control program into said program memory means;
• serial communication interface means in said microcomputer for serially receiving the control program from said first input means;
• and
• second input means surface mounted on said circuit board and connected to a third one of said input terminals for receiving from a source, external to said circuit board, a write mode signal, wherein:
• said microcomputer is responsive to the write mode signal to apply the write control signal to said write control means;
• and
• said write control means is responsive to the write control signal from said microcomputer, for controlling said program memory means to permit writing of the control program received by said serial communication interface means into said program memory means.