Apparatus and method for controlling electric power supply in nonvolatile memory rewriting operation
First Claim
1. An electronic control apparatus comprising:
- a rewritable nonvolatile memory for storing in respective storage areas thereof a control program for controlling a predetermined control object and a rewriting processing program, which includes a rewriting program for executing a rewriting or a boot program for reading in the rewriting program from an outside;
electronic control means for executing a processing corresponding to the control program or the rewriting processing program stored in the nonvolatile memory; and
electric power control means for holding an electric power supply in response to an instruction from the electronic control means even when the electric power supply to the electronic control means is interrupted externally, wherein the electronic control means interrupts an entire electric power supply upon an external interruption of the electric power supply when the storage area of the control program in the nonvolatile memory is being rewritten, and the electronic control means holds the electric power supply irrespective of the external interruption of the electric power supply by controlling the electric power control means when the storage area of the rewriting processing in the nonvolatile memory is being rewritten.
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Accused Products
Abstract
A boot program or an internal combustion engine control program and data stored in a flash ROM is rewritten in a flash ROM rewriting processing by a microcomputer of an ECU. In this instance, a main relay control circuit is controlled to hold an electric power supply from a main relay, as the rewriting is disabled to be made repeatedly once the electric power supply is interrupted in the midst of the boot program. An entire electric power supply is interrupted by an ignition switch to enable the interruption in the midst of rewriting with respect to other programs. Thus, the electric power supply at the time of the program rewriting can be set to hold/stop in correspondence with the importance of the programs stored in the flash ROM.
22 Citations
8 Claims
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1. An electronic control apparatus comprising:
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a rewritable nonvolatile memory for storing in respective storage areas thereof a control program for controlling a predetermined control object and a rewriting processing program, which includes a rewriting program for executing a rewriting or a boot program for reading in the rewriting program from an outside;
electronic control means for executing a processing corresponding to the control program or the rewriting processing program stored in the nonvolatile memory; and
electric power control means for holding an electric power supply in response to an instruction from the electronic control means even when the electric power supply to the electronic control means is interrupted externally, wherein the electronic control means interrupts an entire electric power supply upon an external interruption of the electric power supply when the storage area of the control program in the nonvolatile memory is being rewritten, and the electronic control means holds the electric power supply irrespective of the external interruption of the electric power supply by controlling the electric power control means when the storage area of the rewriting processing in the nonvolatile memory is being rewritten. - View Dependent Claims (2, 3, 4)
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5. A control method for an electronic control apparatus which is rendered operative with an electric power supply through a relay controllable by an external switch and capable of rewriting a control program for controlling a control object and a rewriting processing program including a boot program stored in a nonvolatile memory, the control method comprising the steps of:
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checking whether the control program and the rewriting processing program in the nonvolatile memory is requested to be rewritten by a memory rewriting device external of the electronic control apparatus;
generating a relay control signal when the checking step determines that the rewriting processing program in the nonvolatile memory is requested to be rewritten; and
controlling the electric power supply through the relay in response to the external switch when the relay control signal is absent, and in response to the relay control signal irrespective of the external switch when the relay control signal is present, so that the electric power supply is continued when the rewriting processing program is rewritten. - View Dependent Claims (6, 7, 8)
copying a memory rewriting program from a memory rewriting device into a volatile memory of the electronic control apparatus when a rewriting is requested from the memory rewriting device; and
rewriting the boot program in the nonvolatile memory with a new boot program read out from the memory rewriting device.
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7. A control method as in claim 5, further comprising the steps of:
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copying a memory rewriting program of the rewriting processing program from the nonvolatile memory into a volatile memory of the electronic control apparatus when a rewriting is requested from the memory rewriting device; and
rewriting at least one of the boot program and a memory rewriting program in the nonvolatile memory with a new one of a boot program and a memory rewriting program read out from the memory rewriting device.
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8. A control method as in claim 5, wherein the control object is an internal combustion engine, and an external switch is an ignition switch.
Specification