Claims
- 1. A method for data communication between a voltage regulator and a powertrain controller, said voltage regulator configured to transmit a first signal to said powertain controller and said powertrain controller configured to transmit a second to said voltage regulator, said method comprising the steps of:
- measuring a frequency of said first signal; and
- adjusting a frequency of said second signal in response to said measured frequency.
- 2. A method as recited in claim 1, wherein the step of adjusting a frequency of said second signal further comprises setting said frequency of said second signal proportional said frequency of said first signal.
- 3. A method as recited in claim 2, wherein the step of adjusting a frequency of said second signal further comprises setting said frequency of said second signal equal to said frequency of said first signal.
- 4. An apparatus adapted for data communication, said apparatus comprising:
- a first electronic device;
- a second electronic device;
- wherein said first electronic device is adapted to transmit a first signal to said second electronic device and said second electronic device is adapted to transmit a second signal to said first electronic device;
- wherein said second electronic device further comprises means for measuring a frequency of said first signal and means for adjusting a frequency of said second signal in response to said measured frequency;
- wherein said means for adjusting a frequency of said second signal further comprises means for setting said frequency of said second signal equal to said frequency of said first signal;
- wherein said second device comprises a crystal as a time base for said second signal; and
- wherein said first device comprises an R-C oscillator as a time base for said first signal.
- 5. An apparatus as recited in claim 4, wherein:
- said first device is a voltage regulator for an automotive alternator; and
- said second device is a powertrain control module.
- 6. A method for data communication between a first device and a second device, said first device configured to transmit a first signal to said second device and said second device configured to transmit a second signal to said first device, said method comprising the steps of:
- transmitting said second signal using a first oscillator as a time base;
- transmitting said first signal using a second oscillator as a time base, said second oscillator having lesser frequency stability than said first oscillator;
- measuring a frequency of said first signal; and
- adjusting a frequency of said second signal in response to said measured frequency;
- wherein the step of adjusting a frequency of said second signal further comprises setting said frequency of said second signal proportional to said frequency of said first signal.
- 7. A method as recited in claim 6, wherein:
- transmitting said second signal using a first oscillator as a time base further comprises the step of using a crystal oscillator as said first oscillator; and
- transmitting said first signal using a second oscillator as a time base further comprises the step of using an R-C oscillator as said second oscillator.
- 8. A method for data communication between a first device and a second device, said first device configured to transmit a first signal to said second device and said second device configured to transmit a second signal to said first device, said method comprising the steps of:
- transmitting said second signal using a first oscillator as a time base;
- transmitting said first signal using a second oscillator as a time base, said second oscillator having lesser frequency stability than said first oscillator;
- measuring a frequency of said first signal; and
- adjusting a frequency of said second signal in response to said measured frequency.
- 9. A method as recited in claim 8, wherein:
- transmitting said second signal using a first oscillator as a time base further comprises the step of using a crystal oscillator as said first oscillator; and
- transmitting said first signal using a second oscillator as a time base further comprises the step of using an R-C oscillator as said second oscillator.
- 10. A method for data communication between a first device and a second device, said first device configured to transmit a first signal to said second device and said second device configured to transmit a second signal to said first device, said method comprising the steps of:
- transmitting said second signal using a crystal oscillator as a time base;
- transmitting said first signal using an R-C oscillator as a time base;
- measuring a frequency of said first signal; and
- adjusting a frequency of said second signal in response to said measured frequency.
- 11. A method for data communication between a first device and a second device, said first device configured to transmit a first signal to said second device and said second device configured to transmit a second signal to said first device, said method comprising the steps of:
- transmitting said second signal using a crystal oscillator as a time base;
- transmitting said first signal using an R-C oscillator as a time base;
- measuring a frequency of said first signal; and
- adjusting a frequency of said second signal in response to said measured frequency;
- wherein the step of adjusting a frequency of said second signal further comprises setting said frequency of said second signal equal to said frequency of said first signal.
- 12. An apparatus adapted for data communication, said apparatus comprising:
- a first electronic device;
- a second electronic device;
- wherein said first electronic device is adapted to transmit a first signal to said second electronic device and said second electronic device is adapted to transmit a second signal to said first electronic device;
- wherein said second electronic device further comprises means for measuring a frequency of said first signal and means for adjusting a frequency of said second signal in response to said measured frequency;
- wherein said second electronic device contains a first oscillator as a time base for said second signal; and
- wherein said first electronic device contains a second oscillator of lesser frequency stability than said first oscillator as a time base for said first signal.
- 13. An apparatus as recited in claim 12, wherein: said first oscillator is a crystal oscillator; and said second oscillator is an R-C oscillator.
- 14. An apparatus adapted for data communication, said apparatus comprising:
- a first electronic device;
- a second electronic device;
- wherein said first electronic device is adapted to transmit a first signal to said second electronic device and said second electronic device is adapted to transmit a second signal to said first electronic device;
- wherein said second electronic device further comprises means for measuring a frequency of said first signal and means for adjusting a frequency of said second signal in response to said measured frequency;
- wherein said first electronic device contains an R-C oscillator as a time base for said first signal; and
- wherein said second electronic device contains a crystal oscillator as a time base for said second signal.
Parent Case Info
This is a continuation of application Ser. No. 08/353,601 filed Dec. 12, 1994 abandoned.
US Referenced Citations (10)
Continuations (1)
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Number |
Date |
Country |
Parent |
353601 |
Dec 1994 |
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