HAMMING-DISTANCE ANALYZER

• US 20180151245A1
• Filed: 01/30/2017
• Published: 05/31/2018
• Est. Priority Date: 11/28/2016
• Status: Active Grant

• Current Assignee: First Midwest Bank (First Midwest Bancorp Incorporated), Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Lu, Shih-Lien Linus, Li, Kun-hsi, ADHAM, Saman M.I.
• Granted Patent: US 10,515,710 B2
• Time in Patent Office: Days
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 29/08 Functional testing, e.g. testing during refresh, power-on self testing [POST] or distributed testing
• CPC Class Codes: G11C 29/52 Protection of memory contents; Detection of errors in memory contents
• CPC Class Codes: G11C 29/56008 Error analysis, representation of errors
• CPC Class Codes: G11C 29/56016 Apparatus features

Abstract

A device is disclosed that includes a memory array, a comparing circuit, and a calculating circuit. The memory array is configured to store a first response of an under-test device. The comparing circuit is configured to compare the first response with a plurality of responses of the under-test device operated in conditions that are different from each other to generate comparing results. The calculating circuit is configured to output a maximum hamming distance between two of the first response and the plurality of responses according to the comparing results.

Claims

1. A device, comprising:

a memory array configured to store a first response of an under-test device;

a comparing circuit configured to compare the first response with a plurality of responses of the under-test device operated in conditions that are different from each other, to generate comparing results; and

a calculating circuit configured to output, according to the comparing results, a maximum hamming distance between two of the first response and the plurality of responses.

2. The device of claim 1, further comprising:

a register configured to store the comparing results for the calculation of the maximum hamming distance.

3. The device of claim 1, wherein the comparing circuit comprises:

an exclusive OR gate configured to perform an exclusive OR operation of the first response and each one of the plurality of responses.

4. The device of claim 1, wherein the comparing circuit comprises:

at least one exclusive OR gate configured to perform an exclusive OR operation of bits of the first response and corresponding bits of one response of the plurality of response.

5. The device of claim 1, wherein the memory array is a duplicate of an under-test memory array implemented in or by the under-test device.

6. The device of claim 1, wherein the calculating circuit comprises:

a counter configured to generate a value indicating a number of bits, in a corresponding comparing result of the comparing results, having a same logic value.

7. The device of claim 6, wherein the calculating circuit is further configured to generate the maximum hamming distance according to the value and a bit number of the corresponding comparing result.

8. A method, comprising:

retaining a first response of an under-test device in a first operating condition;

sequentially comparing the first response with a plurality of responses of the under-test device in operating conditions that are different from each other, to generate comparing results, wherein each comparing result of the comparing results is generated by adjusting a previous comparing result of the comparing results; and

obtaining, according to the comparing results, a maximum difference between two of the first response and the plurality of responses of the under-test device.

9. The method of claim 8, wherein retaining the first response comprises:

duplicating the first response into a memory array; and

retaining the duplicated first response in the memory array.

10. The method of claim 8, wherein retaining the first response comprises:

generating the first response by a duplicate memory array.

11. The method of claim 8, further comprising:

temporarily storing the comparing results for the calculation of the maximum hamming distance.

12. The method of claim 8, wherein comparing the first response with the plurality of responses comprises:

performing an exclusive OR operation of the first response and a second response in the plurality of responses, to generate a first comparing result of the comparing results.

13. The method of claim 12, wherein comparing the first response with the plurality of responses further comprises:

retaining an Xth bit of the first comparing result if the Xth bit of the first comparing result is equal to a logic value,

wherein the first comparing result has n bits, X and n are each a positive integer, and X is smaller than or equal to n.

14. The method of claim 13, wherein comparing the first response with the plurality of responses further comprises:

performing the exclusive OR operation on the first response and a third response in the plurality of responses; and

changing a Yth bit of the first comparing result if the Yth bit of the first response is different from the Yth bit of the third response,

wherein Y is a positive integer, Y is smaller than or equal to n, and Y is different from X.

15. The method of claim 8, wherein obtaining the maximum difference comprises:

generating a value indicating a number of bits, in a corresponding comparing result of the comparing results, having a same logic value.

16. The method of claim 15, wherein outputting the maximum hamming distance further comprises:

generating the maximum hamming distance according to the value and a bit number of the corresponding comparing result.

17. The method of claim 8, wherein comparing the first response with the plurality of responses comprises:

performing an exclusive OR operation of the first response and each one of the plurality of responses.

18. The method of claim 8, wherein at least one of the first operating condition and the operating conditions corresponds to at least one of a supply voltage of the under-test device, an operating temperature of the under-test device, an operating frequency of the under-test device, or the combination thereof.

19. A method, comprising:

operating an under-test device in conditions that are different from each other, to obtain a plurality of responses of the under-test device;

performing an exclusive OR operation of a first response of the plurality of responses and other responses of the plurality of responses sequentially, to generate a final comparing result; and

outputting, according to the final comparing result, a maximum hamming distance between two of the first response and the other responses.

20. The method of claim 19, wherein outputting the maximum hamming distance comprises:

generating a value indicating a number of bits, in the final comparing result, having a same logic value; and

generating the maximum hamming distance according to the value and a bit number of the final comparing result.