Prosecution Insights
Last updated: April 19, 2026
Application No. 18/456,152

Methods and Apparatus for Probabilistic Refresh in Volatile Memory Devices

Final Rejection §103
Filed
Aug 25, 2023
Examiner
NGUYEN, VAN THU T
Art Unit
2824
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Micron Technology, Inc.
OA Round
4 (Final)
83%
Grant Probability
Favorable
5-6
OA Rounds
2y 4m
To Grant
89%
With Interview

Examiner Intelligence

Grants 83% — above average
83%
Career Allow Rate
785 granted / 950 resolved
+14.6% vs TC avg
Moderate +7% lift
Without
With
+6.6%
Interview Lift
resolved cases with interview
Typical timeline
2y 4m
Avg Prosecution
31 currently pending
Career history
981
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
44.8%
+4.8% vs TC avg
§102
33.2%
-6.8% vs TC avg
§112
14.5%
-25.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 950 resolved cases

Office Action

§103
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This Office Action is in response to 02/09/2026 Amendment. Claims 6-22, 24-25 are pending and examined. Claims 1-5, 23 have been cancelled. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claims 6-22, 24-25 are rejected under 35 U.S.C. 103 as being unpatentable over US 9,472,261 to Chun et al. (hereafter Chun) in view of US 7,929,368 to Jeddeloh (hereafter Jeddeloh). Regarding independent claim 6, Chun teaches a non-transitory computer readable apparatus comprising a storage medium having a plurality of computer-readable instructions (instructions to perform steps in FIGS. 2-3), the plurality of computer- readable instructions being configured to, when executed by a processing apparatus: receive first data identifying a prescribed minimum level of performance for use during operation of a volatile memory device (FIG. 1: e.g. receiving calibration data according to LUT table 167, which comprises minimum level of performance for use at temperature T1 or T2, see 3:42-45 and 5:13-6:46); access a data structure (LUT 167 of FIG. 1 is seen as statistically-based information when it is applied to the DRAM) comprising: second data identifying a plurality of performance values or ranges (e.g. identifying performance values of error rate of 0, error rate of 1, and error rate of 2 corresponding to the temperature, see 3:42-45 and 5:13-6:46); and third data associated with a refresh rate for the respective ones of the plurality of performance values or ranges (FIG. 1: e.g. refresh rates R1-R3 according to error rates in LUT 167); based at least on the received first data, select one of the third data (FIG. 1: based on the temperature, selecting one of the refresh rates R1-R3 corresponding to selected error rate, also see 5:13-6:46); and cause operation of the volatile memory device with a refresh rate associated with the selected one of the third data (FIG. 5: refresh the DRAM in step 520 with selected refresh rate), Jeddeloh teaches error rates are tracked for different regions within a memory device for refresh rates, wherein the refresh rates comprises a probabilistic refresh scheme (FIG. 3: e.g. comprising memory map 315 and MVEL 324, see 4:43-51) that causes different memory cells or regions of the volatile memory device to be refreshed at different rates based on the probabilistic refresh scheme (see FIG. 4 and 6:31-47). Since Chun and Jeddeloh are both from the same field of endeavor, the purpose disclosed by Jeddeloh would have been recognized in the pertinent art of Chun. It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to refresh different regions of memory device at different refresh rate as needed in order to maximize the performance of the memory device (see 5:53-63). Regarding dependent claim 7, Chun teaches wherein the second data and third data of the data structure are based at least in part on a probabilistic characterization of the memory device (error rate and refresh rate are considered probabilistic considerations). Regarding dependent claim 8, Jeddeloh teaches wherein the plurality of computer-readable instructions are further configured to, when executed by a processing apparatus: receive fourth data indicative of a parameter associated with the volatile memory device (FIG. 1: data from MVEL 324 for tracking different error rates); evaluate the received fourth data indicative of the parameter; and cause, based at least on evaluation of the received fourth data: selection of a different one of the third data from the data structure; and operation of the volatile memory device with a refresh rate associated with the selected different one of the third data (determining a refresh rate corresponding to the new error rate). Regarding dependent claim 9, Chun teaches wherein the first data identifying the prescribed minimum level of performance is based on at least one of a type of application using the volatile memory device, a user of the application, or a predetermined level of granularity for control of the volatile memory device (i.e. error rate is considered granularity for control of the DRAM). Regarding dependent claim 10, Chun teaches wherein the plurality of performance values or ranges comprises information on how the volatile memory device functions based on a given temperature of operation of the volatile memory device (FIG. 1: see T1 and T2 of LUT 167). Regarding dependent claim 11, Jeddeloh teaches wherein the plurality of performance values or ranges comprises a map of performance of the volatile memory device as a function of one or more parameters (FIG. 3: memory map 315 and MVEL 324). Regarding dependent claim 12, Chun teaches wherein the one or more parameters comprises at least a voltage of operation of the volatile memory device (because the refresh rate depends on whether the DRAM/SOC device is operated in power saving mode or in active mode, see 5:35-10:24). Regarding independent claim 13, Chun teaches a computing device (see FIG. 1) comprising: a volatile memory device (FIG. 1: DRAM 120); and a processing apparatus (FIG. 1: SOC 110) configured to: receive first data indicative of a prescribed minimum level of performance of operation of the volatile memory device (FIG. 1: e.g. receiving calibration data according to LUT table 167, which comprises minimum level of performance for use at temperature T1 or T2, see 3:42-45 and 5:13-6:46); access a data structure (LUT 167 of FIG. 1 is seen as statistically-based information when it is applied to the DRAM) comprising: second data identifying a plurality of performance values or ranges (e.g. identifying performance values of error rate of 0, error rate of 1, and error rate of 2 corresponding to the temperature, see 3:42-45 and 5:13-6:46); and third data associated with a refresh rate of the respective ones of the plurality of performance values or ranges (FIG. 1: e.g. refresh rates R1-R3 according to error rates in LUT 167); based at least on the received first data, select one of the third data (FIG. 1: based on the temperature, selecting one of the refresh rates R1-R3 corresponding to selected error rate, also see 5:13-6:46); and cause operation of the volatile memory device with a refresh rate associated with the selected one of the third data (FIG. 5: refresh the DRAM in step 520 with selected refresh rate), Jeddeloh teaches error rates are tracked for different regions within a memory device for refresh rates, wherein the refresh rates comprises a probabilistic refresh scheme (FIG. 3: e.g. comprising memory map 315 and MVEL 324, see 4:43-51) that causes different memory cells or regions of the volatile memory device to be refreshed at different rates based on the probabilistic refresh scheme (see FIG. 4 and 6:31-47). Since Chun and Jeddeloh are both from the same field of endeavor, the purpose disclosed by Jeddeloh would have been recognized in the pertinent art of Chun. It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to refresh different regions of memory device at different refresh rate as needed in order to maximize the performance of the memory device (see 5:53-63). Regarding dependent claims 14-17, 19, see rejections applied to claims 7-11 above. Regarding dependent claim 18, Chun teaches wherein the given temperature comprises an on-die measurement of the volatile memory device (FIG. 1: temperature sensor 122 is in DRAM 120). Regarding dependent claim 20, Chun teaches wherein the one or more parameters comprises at least one of temperature, voltage, load, or user activity (because the refresh rate depends on whether the DRAM/SOC device is operated in power saving mode or in active mode, see 5:35-10:24. The power saving mode or active mode are related to user activity). Regarding dependent claim 21, Chun teaches wherein the one or more parameters comprises at least one of an on-die temperature or an ambient temperature (FIG. 1: temperature obtained from temperature sensor 122 is in DRAM 120 is on-die temperature). Regarding independent claim 22, Chun teaches a method comprising: receiving first data indicative of a prescribed minimum level of performance of operation of a volatile memory device (FIG. 1: e.g. receiving calibration data according to LUT table 167, which comprises minimum level of performance for use at temperature T1 or T2, see 3:42-45 and 5:13-6:46); accessing a data structure comprising: second data identifying a plurality of performance values or ranges (e.g. identifying performance values of error rate of 0, error rate of 1, and error rate of 2 corresponding to the temperature, see 3:42-45 and 5:13-6:46); and third data associated with a refresh rate of the respective ones of the plurality of performance values or ranges (FIG. 1: e.g. refresh rates R1-R3 according to error rates in LUT 167), wherein the second data and third data of the data structure are based on least in part on probabilistic characterization of the memory device (LUT 167 of FIG. 1 is seen as statistically-based information when it is applied to the DRAM); based at least on the received first data, selecting one of the third data (FIG. 1: based on the temperature, selecting one of the refresh rates R1-R3 corresponding to selected error rate, also see 5:13-6:46); and causing operation of the volatile memory device with a refresh rate associated with the selected one of the third data (FIG. 5: refresh the DRAM in step 520 with selected refresh rate), Jeddeloh teaches error rates are tracked for different regions within a memory device for refresh rates, wherein the refresh rates comprises a probabilistic refresh scheme (FIG. 3: e.g. comprising memory map 315 and MVEL 324, see 4:43-51) that causes different memory cells or regions of the volatile memory device to be refreshed at different rates based on the probabilistic refresh scheme (see FIG. 4 and 6:31-47). Since Chun and Jeddeloh are both from the same field of endeavor, the purpose disclosed by Jeddeloh would have been recognized in the pertinent art of Chun. It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to refresh different regions of memory device at different refresh rate as needed in order to maximize the performance of the memory device (see 5:53-63). Regarding dependent claims 24-25, see rejection applied to claims 7-9. Response to Arguments Applicant’s arguments, filed on 02/09/2026, with respect to the rejection of claims 6, 13 and 22 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of additional reference to Jeddeloh as stated above. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to VANTHU NGUYEN whose telephone number is (571)272-1881. The examiner can normally be reached M-F: 7:00AM - 3:00PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Richard Elms can be reached on (571) 272-1869. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. February 19, 2026 /VANTHU T NGUYEN/Primary Examiner, Art Unit 2824
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Prosecution Timeline

Aug 25, 2023
Application Filed
Mar 01, 2025
Non-Final Rejection — §103
Jun 05, 2025
Response Filed
Jul 07, 2025
Final Rejection — §103
Sep 09, 2025
Response after Non-Final Action
Oct 09, 2025
Request for Continued Examination
Oct 13, 2025
Response after Non-Final Action
Nov 05, 2025
Non-Final Rejection — §103
Feb 09, 2026
Response Filed
Feb 19, 2026
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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MEMORY DEVICE INCLUDING INTERFACE CIRCUIT AND METHOD OF OPERATING THE SAME
2y 5m to grant Granted Mar 31, 2026
Patent 12587418
MULTIPLEXING DISTINCT SIGNALS ON A SINGLE PIN OF A MEMORY DEVICE
2y 5m to grant Granted Mar 24, 2026
Patent 12573450
SRAM COLUMN SLEEP CIRCUITS FOR LEAKAGE SAVINGS WITH RAPID WAKE
2y 5m to grant Granted Mar 10, 2026
Patent 12573449
METHODS OF TESTING NONVOLATILE MEMORY DEVICES AND NONVOLATILE MEMORY DEVICES
2y 5m to grant Granted Mar 10, 2026
Patent 12567470
SYSTEM AND METHOD FOR DYNAMIC INTER-CELL INTERFERENCE COMPENSATION IN NON-VOLATILE MEMORY STORAGE DEVICES
2y 5m to grant Granted Mar 03, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
83%
Grant Probability
89%
With Interview (+6.6%)
2y 4m
Median Time to Grant
High
PTA Risk
Based on 950 resolved cases by this examiner. Grant probability derived from career allow rate.

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