Patent ID: 7345940
Filing Date: 2008-03-18
Classification: G11C

Abstract:
1. A method for selectively refreshing rows of memory cells in one or more semiconductor memory devices, comprising: monitoring, by a memory controller coupled with the semiconductor memory devices, write operations to the memory cells; maintaining a plurality of bits indicative of rows containing memory cells involved in the monitored write operations on the memory controller; transferring a first plurality of the bits to a first memory device; placing the first memory device in a self-refresh mode, in which refresh operations are performed for only those rows containing memory cells involved in the monitored write operations, as indicated by the first plurality of bits; transferring a second plurality of the bits to a second memory device; and placing the second memory device in a self-refresh mode, in which refresh operations are performed for only those rows containing memory cells involved in the monitored write operations, as indicated by the second plurality of bits.