HYBRID REFRESH WITH HIDDEN REFRESHES AND EXTERNAL REFRESHES

摘要

A memory subsystem enables satisfying refresh needs for a memory device with hidden refreshes performed by the memory device in response to Activate commands, and external refreshes to make up a difference between the number of hidden refreshes and a minimum number of total refreshes needed during a refresh window. With a hidden refresh the memory device executes the Activate command in one memory portion as indicated by the identified memory location of the command, and executes a refresh in a different portion, such as a different sub-bank. By combining external refreshes with hidden refreshes, the memory subsystem can enable hidden refreshes without the hidden refreshes causing a back-off or retry condition from the memory device to the memory controller.