Patent ID: 7120077

Claim:
A memory module, comprising: a mounting substrate, wherein the substrate comprises connections for supplying address and command signals; a plurality of integrated memory components arranged on the mounting substrate, wherein each of the memory components comprises a memory cell array including rows and columns; a refresh control circuit that is arranged separately from the memory components on the mounting substrate, wherein an output of the refresh control circuit is connected to the plurality of integrated memory components and an input of the refresh control circuit is connected to the connections for supplying the address and command signals; and a respective set of counter circuits for independently operated units of rows, wherein the individual counter circuits within a set are associated with a respective different row in the corresponding unit of rows, and a respective counter circuit is reset when an associated row is accessed; wherein the refresh control circuit is designed such that: when address or command signals, which have been generated outside the memory module, are supplied, the refresh control circuit receives and processes the signals, based on the access information obtained therefrom, the refresh control circuit independently generates a refresh command for refreshing the contents of memory cells in a selected one of the memory components, and the refresh control circuit transmits the refresh command to the selected memory component; and the refresh control circuit ascertains which rows in a selected memory component have not been accessed in a predefined period of time and, based on this evaluation, the refresh control circuit independently determines a point in time at which the refresh command will be sent, the refresh control circuit being configured to evaluate the counter circuits with respect to a count and, based on such evaluation, independently determining the point in time at which the refresh command will be sent.