Abstract:
A memory controller and buffers on memory modules each operate in two modes, depending on the type of motherboard through which the controller and modules are connected. In a first mode, the controller transmits decoded chip-select signals independently to each module, and the motherboard data channel uses multi-drop connections to each module. In a second mode, the motherboard has point-to-point data channel and command address connections to each of the memory modules, and the controller transmits a fully encoded chip-select signal group to each module. The buffers operate modally to correctly select ranks or partial ranks of memory devices on one or more modules for each transaction, depending on the mode.
Abstract:
The embodiments described herein describe technologies for memory systems. One implementation of a memory module includes multiple device sites coupled to the a data query (DQ) buffer component via data lines and coupled to a command and address (CA) buffer component via chip select (CS) lines. A first number of the CS lines between the CA buffer component and any combination of two or more of the multiple device sites is greater than a second number of the CS lines between the CA buffer component and a single one of the multiple device sites.