Compact fault detecting system capable of detecting fault without omission
AssigneeNEC Corporation
InventorHirotaka Nakano
Life of this patent
Estimating the term…
Abstract
A fault detection system applies known data to the input of a circuit being inspected for faults and examines the circuit output for expected results. Faults in a circuit are detected by receiving unexpected results at the circuit output. A fault detection circuit provides a fault signal that is enabled only when a reset line is activated. Activation of the reset line also prompts the known data to be applied to the circuit input. The known data can be derived from memory storage units that provide a known output upon activation of the reset signal. Accordingly, the system does not require parity bits or excessive hardware to provide fault detection for almost all modes of failure in a given circuit.
Claims9
A fault detection system for detecting faults in a circuit, said fault detection system comprising:
- a data storage element having a storage output;
- a reset signal coupled to said storage element;
- said storage element effective to apply a fault detection data value to said storage output when said reset signal is active;
- said storage output coupled to a circuit input of said circuit;
- a circuit output of said circuit providing an output signal related to said circuit input;
- and
- a fault detector coupled to said circuit output, said fault detector operable to determine whether said circuit output includes a fault based on said circuit input when said fault detection data value is applied to said storage output.
A method of detecting a fault in a circuit, said method comprising:
- activating a reset signal;
- applying a fault detection data value to said circuit when a reset signal is active;
- analyzing a circuit output of said circuit to detect a fault based on an expected value of said circuit output resulting from application of said fault detection data value;
- and
- enunciating detected faults.
Dependencies are inferred from the claim text.