US 11,688,451 B2
Apparatuses, systems, and methods for main sketch and slim sketch circuit for row address tracking
Yu Zhang, Shanghai (CN); and Liang Li, Shanghai (CN)
Assigned to Micron Technology, Inc., Boise, ID (US)
Filed by MICRON TECHNOLOGY, INC., Boise, ID (US)
Filed on Nov. 29, 2021, as Appl. No. 17/456,849.
Prior Publication US 2023/0170008 A1, Jun. 1, 2023
Int. Cl. G11C 11/406 (2006.01)
CPC G11C 11/406 (2013.01) 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a refresh control circuit comprising:
a first sketch circuit configured to update selected ones of a first plurality of count values based on a row address;
a second sketch circuit configured to update selected ones of a second plurality of count values based on the row address when at least one of the selected ones of the first plurality of count values exceeds a first threshold;
a targeted refresh queue configured to store the row address when a maximum of the minimum of the selected ones of the first plurality of count values and the minimum of the selected ones of the second plurality of count values exceeds a second threshold; and
a refresh address generator configured to generate a targeted refresh address based on the row address in the targeted refresh queue.