Vehicle-mounted electronic control apparatus
First Claim
1. A vehicle-mounted electronic control apparatus comprising:
- a main CPU including a first nonvolatile memory in which at least control programs and control constants, in correspondence with types of controlled vehicles, transmitted from an external tool are written, the main CPU including a first RAM for calculation processing;
a sub CPU including a second nonvolatile memory in which programs for input/output processing are written and a second RAM for calculation processing; and
a serial-parallel converter for serial communication adapted to transmit a plurality of input signals, which are input to the sub CPU, to the main CPU, wherein a plurality of filter constants corresponding to the plurality of input signals are stored in at least one of the first and second nonvolatile memory; and
the sub CPU has a digital filter section adapted to perform predetermined calculation based on the filter constants to transmit a result of the calculation to the main CPU.
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Abstract
A vehicle-mounted electronic control apparatus comprises:
a main CPU including a first nonvolatile memory in which at least control programs and control constants, in correspondence with types of controlled vehicles, transmitted from an external tool are written, the main CPU including a first RAM for calculation processing;
a sub CPU including a second nonvolatile memory in which programs for input/output processing are written and a second RAM for calculation processing; and
a serial-parallel converter for serial communication adapted to transmit a plurality of input signals, which are input to the sub CPU, to the main CPU,
wherein a plurality of filter constants corresponding to the plurality of input signals are stored in at least one of the first and second nonvolatile memory; and
the sub CPU has a digital filter section adapted to perform predetermined calculation based on the filter constants to transmit a result of the calculation to the main CPU.
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Citations
10 Claims
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1. A vehicle-mounted electronic control apparatus comprising:
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a main CPU including a first nonvolatile memory in which at least control programs and control constants, in correspondence with types of controlled vehicles, transmitted from an external tool are written, the main CPU including a first RAM for calculation processing;
a sub CPU including a second nonvolatile memory in which programs for input/output processing are written and a second RAM for calculation processing; and
a serial-parallel converter for serial communication adapted to transmit a plurality of input signals, which are input to the sub CPU, to the main CPU, wherein a plurality of filter constants corresponding to the plurality of input signals are stored in at least one of the first and second nonvolatile memory; and
the sub CPU has a digital filter section adapted to perform predetermined calculation based on the filter constants to transmit a result of the calculation to the main CPU. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
the plurality of analog signals are conducted digital conversion into a plurality of digital converted values through an A/D converter and a digital filter including a switched capacitor periodically charged and discharged by a changeover switch and a setting unit of a charge and discharge cycle; and
the digital filter section performs predetermined calculation using the digital converted values to transmit a result of the calculation to the main CPU.
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4. The vehicle-mounted electronic control apparatus according to claim 1, wherein the plurality of input signals input to the sub CPU are a plurality of on-off signals input through a bleeder resistor with a low resistance acting as a load to an input switch, a noise filter including a series resistor with a high resistance and a capacitor with a small capacity, and a comparator for level determination having a hysteresis function;
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the digital filter section has an input confirmation section adapted to sample outputs from the comparator for level determination in a predetermined cycle to make an ON determination when positive results of the continuous plurality of sampling results are 50% or more and to make an OFF determination if the positive results of the continuous plurality of sampling results are less than 50%; and
outputs of the input confirmation section are transmitted to the main CPU.
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5. The vehicle-mounted electronic control apparatus according to claim 4, wherein the digital filter section comprises a setting section adapted to set at least one of a sampling cycle and the number of logical determination points of the comparator for level determination.
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6. The vehicle-mounted electronic control apparatus according to claim 4, wherein a determination value to make the input confirmation section output an ON is variable in a range of proportion of the positive results in the plurality of sampling results from 50% to 100%.
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7. The vehicle-mounted electronic control apparatus according to claim 1, further comprising a retransmission determination section,
wherein the filter constants are constants, which are corresponding to types of controlled vehicles, written in the first nonvolatile memory of the main CPU; -
the filter constants are transferred to the second RAM of the sub CPU through the serial-parallel converter for serial communication;
a sum check of setting constants including the filter constants used in the digital filter section of the sub CPU is performed in the sub CPU;
when a check sum error occurs, the retransmission determination section again transfers the filter constants from the main CPU to the sub CPU.
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8. The vehicle-mounted electronic control apparatus according to claim 1, further comprising:
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a transfer section adapted to transfer the filter constants to the first RAM;
a control constant correction section adapted to correct control constants including the filter constants stored in the first RAM; and
a control constant transfer section adapted to transfer the corrected control constants to the second RAM of the sub CPU through the serial-parallel converter for serial communication, wherein the filter constants are constants, which are corresponding to the types of controlled vehicles, written in the first nonvolatile memory of the main CPU; and
the control constants are used as setting constants of the digital filter section of the sub CPU.
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9. The vehicle-mounted electronic control apparatus according to claim 1, wherein an input/output interface circuit for high-speed processing capable of inputting/outputting to the main CPU directly without intervention of the sub CPU is connected to a data bus of the main CPU;
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a signal input to the sub CPU through the input/output interface circuit is monitored by the sub CPU to transmit a monitor result to the main CPU.
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10. The vehicle-mounted electronic control apparatus according to claim 1, further comprising:
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a removable connector adapted to connect an external tool;
a serial communication interface adapted to connect the external tool to the main CPU; and
a writing mode determination section adapted to respond to operations of a part of the plurality of input signals supplied to the sub CPU and to generate a writing control signal from the sub CPU based on programs stored in the second nonvolatile memory, wherein the writing control signal is supplied to a writing control terminal of the main CPU to transfer and write the control programs and the control constants from the external tool to the first nonvolatile memory.
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Specification