On-vehicle control apparatus
First Claim
1. An on-vehicle control apparatus, comprising:
- a CPU for controlling an on-vehicle device based on a control program using various control variables;
a rewritable non-volatile memory for storing the control program;
a backup RAM for storing the control variables therein;
a backup power supply circuit for supplying power to the backup RAM;
a boot program for causing the CPU to rewrite the control program;
an address changeover circuit for making a changeover in an execution address of the CPU to the boot program in rewriting the control program; and
a memory rewrite unit, wherein;
the memory rewrite unit outputs a rewrite signal for causing the address changeover circuit to operate, a command signal group including a command for activating the boot program, and an erasure command signal for erasing a diagnostic code after the control program has been rewritten; and
the control program initializes the control variables in the backup RAM in response to the erasure command signal when being activated after having been rewritten.
1 Assignment
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Accused Products
Abstract
Provided is an on-vehicle control apparatus capable of automatically initializing control variables in a backup RAM only in rewriting a control program in the market. The on-vehicle control apparatus includes a CPU for controlling an on-vehicle device according to a control program, a non-volatile ROM for storing the control program therein, a backup RAM for storing control variables therein, a backup power supply circuit for supplying power to the backup RAM, a boot program for rewriting the control program, an address changeover circuit for making a changeover in execution address, and a memory rewrite unit. The memory rewrite unit outputs a rewrite signal, a command signal group including a command for activating the boot program, and an erasure command signal for erasing a diagnostic code. The control program initializes the control variables in the backup RAM in response to the erasure command signal when being activated after having been rewritten.
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Citations
7 Claims
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1. An on-vehicle control apparatus, comprising:
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a CPU for controlling an on-vehicle device based on a control program using various control variables; a rewritable non-volatile memory for storing the control program; a backup RAM for storing the control variables therein; a backup power supply circuit for supplying power to the backup RAM; a boot program for causing the CPU to rewrite the control program; an address changeover circuit for making a changeover in an execution address of the CPU to the boot program in rewriting the control program; and a memory rewrite unit, wherein; the memory rewrite unit outputs a rewrite signal for causing the address changeover circuit to operate, a command signal group including a command for activating the boot program, and an erasure command signal for erasing a diagnostic code after the control program has been rewritten; and the control program initializes the control variables in the backup RAM in response to the erasure command signal when being activated after having been rewritten. - View Dependent Claims (2, 3, 4)
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5. An on-vehicle control apparatus, comprising:
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a CPU for controlling an on-vehicle device based on a control program using various control variables; a rewritable non-volatile memory for storing the control program therein; a backup RAM for storing the control variables therein; a backup power supply circuit for supplying power to the backup RAM; a boot program for causing the CPU to rewrite the control program; an address changeover circuit for making a changeover in an execution address of the CPU to the boot program in rewriting the control program; and a memory rewrite unit, wherein; the memory rewrite unit outputs a rewrite signal for causing the address changeover circuit to operate, a command signal group including a command for activating the boot program, and an erasure command signal for erasing a diagnostic code after the control program has been rewritten; and the control program compares a criterial value in the non-volatile memory with a predetermined value in the backup RAM, initializes the control variables in the backup RAM when the control program determines that the criterial value does not coincide with the predetermined value, sets the predetermined value to an abnormal value in response to the erasure command signal when being activated after having been rewritten, and initializes the control variables in the backup RAM in response to a failure in coincidence between the abnormal value and the criterial value when being activated next time. - View Dependent Claims (6, 7)
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Specification