Fault detection and prediction for data storage elements

• US 9,390,814 B2
• Filed: 08/07/2014
• Issued: 07/12/2016
• Est. Priority Date: 03/19/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Ellis, Robert W.
• Primary Examiner(s): Sofocleous, Alexander
• Assistant Examiner(s): BERMUDEZ LOZADA, ALFREDO
• Application Number:
  US14/454,683
• Publication Number:
  US 20150270014A1
• Time in Patent Office: 705 Days
• Field of Search: 365/201, 365/185.09, 365/200
• US Class Current: 1/1
• CPC Class Codes: G01R 31/2843 In-circuit-testing
• CPC Class Codes: G11C 2029/0409 Online test
• CPC Class Codes: G11C 2029/5006 Current
• CPC Class Codes: G11C 29/04 Detection or location of defective memory elements , e.g. cell constructio details, timing of test signals
• CPC Class Codes: G11C 29/4401 for self repair

Abstract

A circuit, configured to detect faults in an array of data storage elements, comprises: a resistor network; a switching network for selectively coupling a specified portion of the resistor network to the array of data storage elements; a current monitoring module, where the current monitoring module is operable to monitor current flow through the specified portion of the resistor network; and a control module coupled to the switching network and the current monitoring module. The control module is operable to control the switching network, so as to couple the specified portion of the resistor network to the array of data storage elements, and to determine whether one or more predefined characteristics of the output of the current monitoring module meet predetermined fault criteria. The control module is further operable to initiate one or more remedial actions, when the one or more predefined characteristics meet the predetermined fault criteria.

Claims

1. A circuit to detect faults in one or more arrays of data storage elements, the circuit comprising:

a resistor network comprising two or more resistors;

a switching network for selectively coupling a respective portion of the resistor network to a first array of data storage elements, and the switching network is further operable to couple the respective portion of the resistor network to a second array of data storage elements;

a current monitoring module connected to the resistor network, wherein the current monitoring module is operable to monitor current flow through the respective portion of the resistor network during performance of a respective operation on the first array of data storage elements, wherein the respective operations is a host-initiated memory read operation, host-initiated write operation, or data erase operation; and

a control module coupled to the switching network and the current monitoring module;

wherein the control module is operable to control the switching network, so as to couple the respective portion of the resistor network to the first array of data storage elements, and to determine whether one or more predefined characteristics of the output of the current monitoring module meet predetermined fault criteria; and

wherein the control module is further operable to, in accordance with a determination that the one or more predefined characteristics meet the predetermined fault criteria, initiate one or more remedial actions, wherein the one or more remedial actions comprise;

determining whether data stored in the first array of data storage elements is valid; and

in accordance with a determination that the data stored in the first array of data storage elements is valid, transferring the data stored in the first array of data storage elements to the second array of data storage elements.

2. The circuit of claim 1, wherein:

the current monitoring module comprises a comparator and an amplifier, wherein the comparator is connected to the resistor network and wherein the amplifier comprises a first input coupled to an output of the comparator, a second input coupled to a reference voltage, and an output coupled to the control module; and

the control module is further operable to analyze the output of the amplifier as instantaneous current data.

3. The circuit of claim 1, wherein:

the current monitoring module comprises a comparator and an amplifier, wherein the comparator is connected to the resistor network and wherein the amplifier comprises a first input coupled to an output of the comparator, a second input coupled to sample and hold circuitry, and an output coupled to the sample and hold circuitry and the control module; and

the control module is further operable to analyze the output of the amplifier as peak current data.

4. The circuit of claim 1, wherein:

the current monitoring module comprises a first comparator, a second comparator, and a digital to analog converter (DAC), wherein the first comparator is connected to the resistor network, wherein the DAC comprises a first input coupled to a reference voltage and an output coupled to the second comparator, and wherein the second comparator comprises a first input coupled to the output of the first comparator, a second input coupled to the output of the DAC, and an output coupled to the control module; and

the control module is further operable to analyze the output of the second comparator as adjusted current data.

5. The circuit of claim 1, wherein:

the current monitoring module comprises a comparator and an integrator, wherein the comparator is connected to the resistor network and wherein the integrator comprises a first input coupled to an output of the comparator, a second input coupled to a reference voltage, and an output coupled to the control module; and

the control module is further operable to analyze the output of the integrator as average current data.

6. The circuit of claim 1, wherein the one or more remedial actions comprise marking the first array of data storage elements as a known-bad storage array.

7. The circuit of claim 1, wherein the plurality of arrays of data storage elements comprise arrays of non-volatile data storage elements.

8. The circuit of claim 7, wherein the one or more remedial actions further comprise, in accordance with a determination that the data stored in the first array of data storage elements is invalid, obtaining recovered data corresponding to the data stored in the first array of data storage elements and storing the recovered data to the second array of data storage elements.

9. A circuit to detect faults in one or more arrays of data storage elements, the circuit comprising:

a resistor network comprising two or more resistors;

a switching network for selectively coupling a respective portion of the resistor network to a first array of data storage elements;

a current monitoring module connected to the resistor network, wherein the current monitoring module is operable to monitor current flow through the respective portion of the resistor network; and

a control module coupled to the switching network and the current monitoring module;

wherein the control module is operable to control the switching network, so as to couple the respective portion of the resistor network to the first array of data storage elements, and to determine whether one or more predefined characteristics of the output of the current monitoring module meet predetermined fault criteria;

wherein the control module is further operable to, in accordance with a determination that the one or more predefined characteristics meet the predetermined fault criteria, initiate one or more remedial actions; and

wherein the control module is further operable to;

determine whether one or more predefined characteristics of the recorded data meet predetermined warning criteria and do not meet predetermined fault criteria; and

in accordance with a determination that the one or more predefined characteristics of the recorded data meet the predetermined warning criteria and do not meet the predetermined fault criteria, initiate one or more predictive actions.

10. The circuit of claim 9, wherein the one or more predictive actions comprise transferring the data stored in the first array of data storage elements to a second array of storage elements.

11. The circuit of claim 9, wherein the one or more predictive actions comprise marking the first array of data storage elements as a known-bad storage array.

12. The circuit of claim 9, wherein the one or more predictive actions comprise updating metadata corresponding to the first array of data storage elements.

13. A storage device configured to detect faults in data storage elements, the storage device comprising:

one or more arrays of data storage elements;

a resistor network comprising two or more resistors;

a switching network for selectively coupling a respective portion of the resistor network to a first array of data storage elements, and the switching network is further operable to couple the respective portion of the resistor network to a second array of data storage elements;

a current monitoring module connected to the resistor network, wherein the current monitoring module is operable to monitor current flow through the respective portion of the resistor network during performance of a respective operation on the first array of data storage elements, wherein the respective operations is a host-initiated memory read operation, host-initiated write operation, or data erase operation; and

a control module coupled to the switching network and the current monitoring module;

wherein the control module is operable to control the switching network, so as to couple the respective portion of the resistor network to the first array of data storage elements, and to determine whether one or more predefined characteristics of the output of the current monitoring module meet predetermined fault criteria; and

wherein the control module is further operable to, in accordance with a determination that the one or more predefined characteristics meet the predetermined fault criteria, initiate one or more remedial actions, wherein the one or more remedial actions comprise;

determining whether data stored in the first array of data storage elements is valid; and

in accordance with a determination that the data stored in the first array of data storage elements is valid, transferring the data stored in the first array of data storage elements to the second array of data storage elements in the one or more arrays of data storage elements.

14. The storage device of claim 13, wherein:

the current monitoring module comprises a comparator and an amplifier, wherein the comparator is connected to the resistor network and wherein the amplifier comprises a first input coupled to an output of the comparator, a second input coupled to a reference voltage, and an output coupled to the control module; and

the control module is further operable to analyze the output of the amplifier as instantaneous current data.

15. The storage device of claim 13, wherein:

the current monitoring module comprises a comparator and an amplifier, wherein the comparator is connected to the resistor network and wherein the amplifier comprises a first input coupled to an output of the comparator, a second input coupled to sample and hold circuitry, and an output coupled to the sample and hold circuitry and the control module; and

the control module is further operable to analyze the output of the amplifier as peak current data.

16. The storage device of claim 13, wherein:

the current monitoring module comprises a first comparator, a second comparator, and a digital to analog converter (DAC), wherein the first comparator is connected to the resistor network, wherein the DAC comprises a first input coupled to a reference voltage and an output coupled to the second comparator, and wherein the second comparator comprises a first input coupled to the output of the first comparator, a second input coupled to the output of the DAC, and an output coupled to the control module; and

the control module is further operable to analyze the output of the second comparator as adjusted current data.

17. The storage device of claim 13, wherein:

the current monitoring module comprises a comparator and an integrator, wherein the comparator is connected to the resistor network and wherein the integrator comprises a first input coupled to an output of the comparator, a second input coupled to a reference voltage, and an output coupled to the control module; and

the control module is further operable to analyze the output of the integrator as average current data.

18. The storage device of claim 13, wherein the plurality of arrays of data storage elements comprise arrays of non-volatile data storage elements.

19. The storage device of claim 13, wherein the one or more remedial actions further comprise, in accordance with a determination that the data stored in the first array of data storage elements is invalid, obtaining recovered data corresponding to the data stored in the first array of data storage elements and storing the recovered data to the second array of data storage elements.

20. A storage device configured to detect faults in data storage elements, the storage device comprising:

one or more arrays of data storage elements;

a resistor network comprising two or more resistors;

a switching network for selectively coupling a respective portion of the resistor network to a first array of data storage elements in the one or more arrays of data storage elements;

a current monitoring module connected to the resistor network, wherein the current monitoring module is operable to monitor current flow through the respective portion of the resistor network; and

a control module coupled to the switching network and the current monitoring module;

wherein the control module is operable to control the switching network, so as to couple the respective portion of the resistor network to the first array of data storage elements, and to determine whether one or more predefined characteristics of the output of the current monitoring module meet predetermined fault criteria;

wherein the control module is further operable to, in accordance with a determination that the one or more predefined characteristics meet the predetermined fault criteria, initiate one or more remedial actions; and

wherein the control module is further operable to;

determine whether one or more predefined characteristics of the recorded data meet predetermined warning criteria and do not meet predetermined fault criteria; and

in accordance with a determination that the more predefined characteristics of the recorded data meet the predetermined warning criteria and do not meet the predetermined fault criteria, initiate one or more predictive actions.

21. The storage device of claim 20, wherein the one or more predictive actions comprise transferring the data stored in the first array of data storage elements to a second array of storage elements in the one or more arrays of data storage elements.

22. The storage device of claim 20, wherein the one or more predictive actions comprise marking the first array of data storage elements as a known-bad storage array.

23. The storage device of claim 20, wherein the one or more predictive actions comprise updating metadata corresponding to the first array of data storage elements.