Selective refresh with software components

Abstract

A method of refreshing a memory is disclosed. The method includes accessing from active memory an active memory map. The active memory map is generated by software and identifies addresses corresponding to the active memory and associated refresh criteria for the addresses. The refresh criteria are evaluated for a portion of the active memory, and an operation initiated to refresh a portion of the active memory is based on the refresh criteria.

What is claimed is: 
     
         1 . (canceled) 
     
     
         2 . A method of refreshing allocated portions of a memory, the method comprising:
 sorting the allocated portions to determine a highest priority portion of the allocated portions, the sorting based on a refresh status parameter associated with the allocated portions;   tracking the refresh status parameter of the highest priority portion; and   scheduling a refresh instruction for the highest priority portion based on the tracked refresh status parameter reaching a threshold value.   
     
     
         3 . The method of  claim 2 , wherein:
 the allocated portions each represent a page of memory storage locations corresponding to a page address.   
     
     
         4 . The method of  claim 2 , wherein:
 the refresh status parameter associated with the highest priority portion comprises a count value representing expiration of a retention time associated with the highest priority portion.   
     
     
         5 . The method of  claim 4 , wherein the tracking comprises:
 initiating a page operation;   decrementing the count value in response to the initiating;   determining whether the decremented count reaches the threshold value; and   iteratively repeating the initiating, decrementing and determining until the count reaches the threshold.   
     
     
         6 . The method of  claim 2  wherein sorting and tracking are carried out by operating system software. 
     
     
         7 . The method of  claim 2  wherein the scheduling is carried out by operating system software. 
     
     
         8 . The method of  claim 2 , further comprising:
 after scheduling the refresh instruction, sorting the highest priority portion as a lowest priority portion.   
     
     
         9 . A method, comprising:
 prioritizing refresh operations for a memory device, the prioritizing including
 identifying active portions of the memory device as allocated portions; 
 associating the allocated portions with a refresh status parameter; 
 sorting the allocated portions to determine a highest priority portion of the allocated portions, the sorting based on the refresh status parameter associated with the allocated portions; 
 tracking the refresh status parameter of the highest priority portion; and 
 scheduling a refresh instruction for the highest priority portion based on the tracked refresh status parameter reaching a threshold value. 
   
     
     
         10 . The method of  claim 9  wherein:
 the allocated portions each represent a page of memory storage locations corresponding to a page address. 
 
     
     
         11 . The method of  claim 9 , wherein:
 the refresh status parameter associated with the highest priority portion comprises a count value representing expiration of a retention time associated with the highest priority portion.   
     
     
         12 . The method of  claim 11 , wherein the tracking comprises:
 initiating a page operation;   decrementing the count value in response to the initiating;   determining whether the decremented count reaches the threshold value; and   iteratively repeating the initiating, decrementing and determining until the count reaches the threshold.   
     
     
         13 . The method of  claim 9  wherein sorting and tracking are carried out by operating system software. 
     
     
         14 . The method of  claim 9  wherein the scheduling is carried out by operating system software. 
     
     
         15 . The method of  claim 9 , further comprising:
 after scheduling the refresh instruction, sorting the highest priority portion as a lowest priority portion.   
     
     
         16 . A refresh controller for prioritizing refresh operations for allocated portions of a memory, the refresh controller comprising:
 a tracking module including
 a sorter to sort the allocated portions to determine a highest priority portion of the allocated portions, the sort based on a refresh status parameter associated with the allocated portions, and 
 a tracker to track the refresh status parameter of the highest priority portion; and 
   a refresh manager in communication with the tracker to schedule a refresh instruction for the highest priority portion based on the tracked refresh status parameter reaching a threshold value.   
     
     
         17 . The refresh controller of  claim 16 , wherein:
 the allocated portions each represent a page of memory storage locations corresponding to a page address.   
     
     
         18 . The refresh controller of  claim 16 , wherein:
 the refresh status parameter associated with the highest priority portion comprises a count value representing expiration of a retention time associated with the highest priority portion.   
     
     
         19 . The refresh controller of  claim 18 , wherein:
 the tracker is operative to
 initiate a page operation; 
 decrement the count value in response to the initiating; 
 determine whether the decremented count reaches the threshold value; and 
 iteratively repeat the initiate, decrement and determine until the count reaches the threshold. 
   
     
     
         20 . The refresh controller of  claim 16 , wherein:
 the sorter and the tracker are controlled by operating system software.   
     
     
         21 . The method of  claim 16  wherein:
 the refresh manager is controlled by operating system software.