DDR5 Registering Clock Driver (DDR5 RCD)

The Rambus DDR5 RCD provides Command/Address (CA) and clocks to the DDR5 memory devices in RDIMMs. In DDR5 DIMM architectures, the module is organized into two independent 40-bit subchannels (32 bits data, 8 bits ECC). Each subchannel is organized as either 10 devices in a x4 configuration with 2 ranks or 5 devices in a x8 configuration with 2 ranks. The RCD distributes C/A signals and clocks for each subchannel, rank and nibble. Sideband channel communication with the CPU or motherboard Baseboard Management Controller (BMC) is enabled through a 12.5 MHz (max.) I3C bus interface.  

Features of the DDR5 RCD 

• Supports data rates up to 9600 MT/s 
• Supports clock rates up to 4800 MHz 
• Supports double data rate (DDR) and single data rate (SDR) CA bus 
• Supports two independent subchannels per RDIMM 
• Supports two physical ranks per subchannel, four physical ranks total 
• Supports up to 16 logical ranks (per physical rank) for high capacity RDIMMs 
• Low Power 1.1V VDD 
• 12.5 MHz (max.) I3C bus interface