Patent attributes
A write command is received to store data in a Data Storage Device (DSD). At least one of a Non-Volatile Random Access Memory (NVRAM) and a Storage Class Memory (SCM) is selected for storing the data of the write command based on a number of previously received write commands indicating an address of the write command or a priority of the write command. The SCM has at least one characteristic of being faster than the NVRAM in storing data, using less power to store data, and providing a greater usable life for repeatedly storing data in a same memory location. In one example, at least a portion of the SCM is allocated for use by a host. Logical addresses assigned to the SCM are mapped to device addresses of the NVRAM. The host is provided with an indication of the logical addresses assigned to the SCM.