Refresh circuitry
The present disclosure includes apparatuses and methods related to refresh circuitry. An example apparatus can include a memory array including a main portion and a redundant portion. The apparatus can include refresh circuitry configured to, responsive to a determination of a hammering event, refresh at least a portion of the redundant portion.
1. An apparatus, comprising:
a memory array; and:
circuitry coupled to the memory array to:
refresh a first portion of the memory array at a system refresh rate;
remap a first row of cells of the first portion to a second row of cells in a second portion of the memory array, the second portion comprising multiple rows of cells;
responsive to a determination of a threshold access characteristic corresponding to the first row of cells in the first portion of the memory array, trigger a hammer refresh of all of the second portion of the memory array without determining addresses of rows of the second portion that are adjacent to the second row, wherein the hammer refresh is based on a time interval that is less than a time interval of the system refresh rate in order to continually refresh all of the second portion at a higher frequency than a frequency corresponding to the system refresh, and wherein the higher frequency is an adjustable frequency; and
prevent refreshing, other than the system refresh, of the first portion of the memory array in response to the determination of the threshold access characteristic.
2. The apparatus of claim 1 , wherein the determined threshold access characteristic occurs on a group of cells coupled to an access line of the second portion.
3. The apparatus of claim 1 , comprising a controller configured to, responsive to an attempt to access the first row of memory cells in the first portion whose physical address has been mapped to the second row of cells in the second portion, access the second portion to which the physical address is mapped.
4. The apparatus of claim 3 , wherein the threshold access characteristic comprises the controller accessing the second row of cells in the second portion greater than a threshold quantity of times within a particular amount of time.
5. The apparatus of claim 1 , wherein the circuitry is configured to cause refreshing of all of the second portion without determining which rows of the second portion are adjacent to the second group.
6. A method, comprising:
refreshing a first group of memory cells of a first portion of a memory array at a system refresh rate; and
refreshing a second group of cells in a second portion of the memory array at a higher refresh rate than the system refresh rate to avoid row hammer disturbs within the second portion of the memory array, wherein the refresh of the second group is based on a time interval that is less than a time interval of the system refresh rate of the first group;
wherein the second portion of the array comprises multiple groups of memory cells, wherein the second group of cells is adjacent to a third group of cells in the second portion of the memory array, and wherein the second group of cells in the second portion of the memory array is refreshed without determining an address of the second group of cells in the second portion of the memory array.
7. The method of claim 6 , wherein the second group of memory cells comprises a redundant row of memory cells.
8. The method of claim 7 , wherein the second portion of the memory array comprises multiple groups of memory cells comprising respective rows of memory cells, and wherein the method comprises continuously refreshing the second portion of the memory array at the higher rate responsive to the first group of cells of the first portion being accessed a threshold number of times within the refresh window corresponding to the system refresh rate.