Patent ID: 7231488

Claim:
A method of reducing a rate for refreshing a portion of a dynamic random access memory (DRAM), comprising: providing a first portion of said DRAM comprising a plurality of volatile memory cells permitting refresh at a first rate and a second portion of said DRAM comprising a differing plurality of volatile memory cells permitting refresh at a second rate lower than said first rate; determining, by performing testing, the first and second refresh rates that are permitted for the first and second portions; storing information for distinguishing between said first portion and said second portion and storing information indicating the first and second refresh rates associated with the first and second portions within said DRAM; and accessing said stored information for distinguishing between said first portion and said second portion and accessing said stored information that indicates the first and second refresh rates to determine when and to refresh said first portion at said first rate and to determine when and to refresh said second portion at said second rate.