Patents Examined by Hayward A. Verdon
  • Device for protecting the validity of time sensitive information
    Patent number: 5489095
    Abstract: The clock circuit is formed by an oscillator (10-12) which is coupled to a counter/divider circuit (15) provided with read accesses (30). In order to prevent falsification of its data, the circuit is formed as a protected casing and includes a protected access circuit (50) which is connected between said accesses and the counter/divider circuit. Furthermore, a circuit for monitoring the frequency of the oscillator may be provided (100-50).
    Type: Grant
    Filed: June 23, 1993
    Date of Patent: February 6, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Jean-Louis Goudard, Denis Pottier, Joseph Hoppe