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Electronic control apparatus and method for on-board rewriting of non-volatile memories

  • US 6,636,989 B1
  • Filed: 01/31/2000
  • Issued: 10/21/2003
  • Est. Priority Date: 02/17/1999
  • Status: Expired due to Term
First Claim
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1. An electronic control apparatus comprising:

  • a plurality of computers having respective non-volatile memories which are capable of rewriting storage information in response to data transmitted from an external side, each computer being put in a memory rewriting mode when a rewriting voltage is applied and is released from a reset condition, and terminals of each computer being set to a high impedance condition during a rewriting operation;

    identification signal generating means for generating an identification signal indicative of a main computer among the plurality of computers; and

    reset release signal generating means for generating a reset release signal from one of the plurality of computers to another of the plurality of computers at the time of putting the plurality of computers in the memory rewriting mode, the one and the another of the plurality of computers being determined as the main computer in response to the identification signal and a sub computer, respectively, wherein the main computer is constructed to monitor the sub computer and apply a reset signal to the sub computer to reset the sub computer upon detection of an abnormality in the sub computer, and wherein the main computer is constructed to apply the reset release signal to the sub computer to thereby forcibly release the sub computer from the reset condition before starting the rewriting operation.

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