Single event upset tolerant system and method

• US 6,085,350 A
• Filed: 03/04/1998
• Issued: 07/04/2000
• Est. Priority Date: 03/04/1998
• Status: Expired due to Fees

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Moore, Jason Jonathon, Emmert, Steven Robert, Handly, Paul Robert, Comer, Erwin Perry
• Primary Examiner(s): Nguyen, Hoa T.
• Application Number:
  US09/034,282
• Time in Patent Office: 853 Days
• Field of Search: 714/797, 714/6, 714/7, 714/8, 714/25, 714/47, 714/48, 714/819, 714/820
• US Class Current: 714/797
• CPC Class Codes: G06F 11/185 and the voting is itself performed redundantly
• CPC Class Codes: G06F 11/187 Voting techniques

Abstract

An single event upset (SEU) tolerant system for detecting and correcting an SEU includes a decision element (200) for receiving a plurality of outputs (120) from a plurality of signal generators (105) and producing an output (130) therefrom. The decision element includes voters which provide two levels of voting for the plurality of redundant outputs (120). First-level voters (300) provide intermediate voted outputs (315) which are received by a second-level voter to determine an output (130). An output disabler (400) determines when an output is provided external to the decision element. A plurality of comparators (210) receive intermediate voted outputs (315) from first-level voters and compare with a plurality of outputs from a plurality of signal generators to determine upset detected signals (125). An upset detected signal controls the selection of feedback for an element having experienced an SEU.

Claims

1. An encryption system comprising:

a plurality of redundant encryptors, each for encrypting redundant black data into red data each encryptor having an output; and

a decision element for receiving the output from each of the plurality of encryptors, and

when an upset output for an upset one of the plurality of encryptors fails to compare with the output for a remainder of the plurality of encryptors, controlling feedback to the upset one of the plurality of encryptors to restore the upset encryptor to a correct state.

2. An encryption system as claimed in claim 1 wherein the decision element comprises:

a plurality of first voters for performing a majority voter operation on the output from each of the plurality of encryptors and generating a first voter output; and

a second voter for performing a majority voter operation on the first voter output for each of the plurality of first voters and generating a second voter output representing the voted output of the plurality of encryptors; and

an output disabler for inhibiting the second voter output when a majority of the plurality of upset outputs are asserted.

3. A system comprising:

a plurality of signal generators each having an output; and

a decision element for receiving the output from each of the plurality of signal generators, and

when an upset output for an upset one of the plurality of signal generators fails to compare with the output for a remainder of the plurality of signal generators, controlling feedback to the upset one of the plurality of signal generators to correct the upset output, and

wherein the decision element further comprises;

a plurality of comparators wherein each of the plurality of comparators receives the voter output from at least one of the plurality of voters and the output from at least one of the plurality of signal generators to generate an upset detected signal for each of the plurality of comparators; and

an output disabler for controlling the second voter output based on the upset detected signal from each of the plurality of comparators.

4. A system as claimed in claim 3 wherein each of the plurality of signal generators includes:

means for receiving the output for each of the plurality of signal generators;

means for selecting at least one output of the plurality of signal generators based on the upset detected signal from at least one of the plurality of comparators; and

means for correcting the upset output for the upset one of the plurality of signal generators based on the output of the remainder of the plurality of signal generators and a current input to the upset one.

5. A system as claimed in claim 3 wherein the output disabler comprises a plurality of gates for receiving upset detected signals from the plurality of comparators and allows the second voter output to represent the output of the plurality of signal generators when a minority of the upset detected signals are asserted.

6. A system comprising:

a plurality of signal generators each having an output; and

a decision element for receiving the output from each of the plurality of signal generators, and

when an upset output for an upset one of the plurality of signal generators fails to compare with the output for a remainder of the plurality of signal generators, controlling feedback to the upset one of the plurality of signal generators to correct the upset output, and

wherein each of the plurality of voters comprises;

an exclusive-or gate for receiving a first input and a second input and generating a gated signal; and

a selector for receiving the second input and a third input and determining the voter output based on the second input and the third input and controlled by the gated signal.

7. A system comprising:

a plurality of signal generators each having an output; and

a decision element for receiving the output from each of the plurality of signal generators, and

when an upset output for an upset one of the plurality of signal generators fails to compare with the output for a remainder of the plurality of signal generators, controlling feedback to the upset one of the plurality of signal generators to correct the upset output, and

wherein the voter comprises;

an exclusive-or gate for receiving a first input and a second input and generating a gated signal; and

a selector for receiving the second input and a third input and determining the second voter output based on the second input and the third input and controlled by the gated signal.

8. A decision element comprising:

a plurality of first voters each generating a voted output from an encrypted data signal from each of a plurality of redundant encryptors;

a second voter for receiving the voted output from each of the plurality of first voters and generating a second voted output; and

a comparator for providing an upset detected signal to one of the redundant encryptors when the voted output of one of the first voters fails to compare with the encrypted data signal from said one redundant encryptor, the upset detected signal restoring said one redundant encryptor to a correct state.

9. A decision element as claimed in claim 8 further comprising a plurality of comparators each corresponding with one of the first voters, each comparator receiving the voted output from one of the plurality of first voters and a corresponding one of the encrypted data signals,

each of the plurality of comparators generating an upset detected signal when the voted output and the corresponding encrypted data signal fail to compare, the upset detected signal being provided to the redundant encryptor providing the corresponding encrypted data signal.

10. A decision element as claimed in claim 9 wherein the upset detected signal from each of the plurality of comparators is supplied to a corresponding of the redundant encryptors to determine, in part, the encrypted data signals.

11. A decision element comprising:

a plurality of voters each having a voted output and a plurality of inputs;

a voter for receiving the voted output from each of the plurality of voters and generating a second voted output;

a plurality of comparators each receiving the voted output from at least one of the plurality of voters and at least one of the plurality of inputs, each of the plurality of comparators generating an upset detected signal when the voted output and at least one of the plurality of inputs fail to compare; and

an output disabler to inhibit the second voted output of the decision element when a majority of upset detected signals are asserted.

12. A decision element as claimed in claim 11 wherein the output disabler comprises a plurality of gates for receiving upset detected signals and allowing the second voted output to represent the plurality of inputs when a minority of the upset detected signals are asserted.

13. A decision element comprising:

a plurality of voters each having a voted output and a plurality of inputs; and

a voter for receiving the voted output from each of the plurality of voters and generating a second voted output, and

wherein each of the plurality of voters comprises;

an exclusive-or gate for receiving a first input and a second input and generating a gated signal; and

a selector for receiving the second input and a third input and determining the voted output based on the second input and the third input and controlled by the gated signal.

14. A decision element comprising:

a plurality of voters each having a voted output and a plurality of inputs; and

a voter for receiving the voted output from each of the plurality of voters and generating a second voted output, and

wherein the voter for generating the second voted output comprises;

an exclusive-or gate for receiving a first input and a second input and generating a gated signal; and

a selector for receiving the second input and a third input and determining the second voted output based on the second input and the third input and controlled by the gated signal.

15. A method for identifying and correcting an single event upset from an output of an upset one of a plurality of redundant encryptors, the method comprising the steps of:

receiving encrypted outputs from the plurality of redundant encryptors;

comparing the encrypted outputs from each of the plurality of redundant encryptors in a plurality of first voters to create a first voted output corresponding with each redundant encryptor;

performing a second comparing step of the plurality of first voted outputs in a second voter to create a second voted output for the plurality of redundant encryptors;

identifying the single event upset based on the second voted output; and

correcting the subsequent encrypted output of the upset one of the plurality of redundant encryptors, the upset redundant encryptor determined based on a comprison between the first voted outputs and the encrypted outputs of the corresponding redundant encryptor.

16. A method as claimed in claim 15 wherein the performing the second comparing step further comprises the steps of:

comparing each of the plurality of first voted outputs with the encrypted outputs of the plurality of redundant encryptors to determine an upset detected signal corresponding with each redundant encryptor; and

inhibiting the second voted output when a majority of the upset detected signals are asserted.

17. A method for identifying and correcting an single event upset from an output of an upset one of a plurality of signal generators, the method comprising the steps of:

receiving outputs from the plurality of signal generators;

comparing the outputs from the plurality of signal generators in a plurality of voters to create a plurality of voted outputs;

performing a second comparing step of the plurality of voted outputs in a voter to create a voted output for the plurality of signal generators;

identifying the single event upset based on the voted output; and

correcting the output of the upset one of the plurality of signal generators, the correcting step comprising the steps of;

providing an upset detected signal to the upset one of the plurality of signal generators;

selecting a feedback signal for the upset one of the plurality of signal generators based on the upset detected signal associated therewith; and

generating the output for the upset one of the plurality of signal generators based on an input signal and the feedback signal associated therewith.