Abstract: Memory controller concepts are disclosed in which hardware resources of a memory controller can be re-used or re-configured to accommodate various different memory configurations. The memory configuration may be stored in mode register bits (228), settable by a host or operating system. By re-configuring or reallocating certain resources of a memory controller, for example command logic blocks (A, B, C, D in FIG. 1A), a single controller design can be used to interface efficiently with a variety of different memory components. Command logic blocks that support N×M memory ranks, for example, can be reconfigured to support N ranks and M threads for multi-threaded memories (FIG. 1A). Data buffer (232, 254) depth can be extended by reconfiguring the buffers responsive to the mode register bits (228). Request buffers can be shared across command logic blocks, for example to increase the request buffer depth (FIG. 3A). Unused circuits can be powered down to save power consumption (FIG. 4A).