Gen 2 MRDIMM Multiplexing Data Buffer

The RRG5102X-B10 is a DDR5 Multiplexing Data Buffer (MDB). Its primary function is to demultiplex and buffer data from the host CPU to DRAMs. The host side can operate as x4 with two strobes, or x8 with one. There are two separate DRAM interfaces, each of which can operate as x4 or x8.

The RRG5102X-B10 supports both Mux Mode and Rank Mode. In Mux Mode, the host interface runs at twice the speed of the DRAM interfaces and carries up to two ranks for each of two multiplexed pseudo-channels, which can transmit and receive in the same direction simultaneously. In Rank Mode, the host and DRAM interfaces run at the same speed, and up to four ranks are supported.

The RRG5102X-B10 also has an input-only control bus interface that is connected to a DDR5MRCD02, as well as a dedicated pin for ZQ calibration and loopback outputs for test purposes.