Samsung announces imminent release of a multichip module integrating DRAM and PCM for Smartphone applications

Hot on the heels of Numonyx’ announcement of two commercial PCM (phase-change memory) products (see “Numonyx 128-Mbit serial- and parallel-I/O PCM non-volatile memories now available in volume”), Samsung announced on April 28 that it plans to ship a device “later this quarter” that integrates DRAM and PCM devices into a multichip package (MCP). Samsung has named its flavor of PCM “PRAM” for “Phase-change RAM.” The PRAM in this MCP is a 512-Mbit device and its intended use is for replacing the NOR Flash memory that currently stores code for a Smartphone. Samsung claims that the PCM used in this new device is three times faster than the NOR Flash it replaces.




Perhaps just as important, both the PCM and DRAM chips in the announced MCP employ the LPDDR2 interface. Consequently the MCP need only present one LPDDR2 interface and one set of pins to the outside world, while distributing the LPDDR2 signals to the two chips internally. In addition, the Smartphone SOC or ASSP only needs one LPDDR2 interface and one set of interface pins to connect to the announced device. These pin efficiencies are no doubt possible because of the LPDDR2-NVM interface extensions specifically created to allow non-volatile memory to easily coexist with LPDDR2 memories (see “State-of-the-Art in Low-Power Memory: Denali’s MemCon”). Although the LPDDR2-NVM spec was developed for Flash devices, it appears to work just as well for PCM devices.

Note that Samsung’s announcement differs from the Numonyx announcement of commercial devices in one significant way. Numonyx announced the immediate availability of its two PCM devices in production volume and included the immediate availability of downloadable, detailed data sheets. Samsung’s announcement is of the imminent shipment of a PCM-based device.