A Data Storage Device (DSD) includes a first memory for storing data and a Storage Class Memory (SCM) for storing data. The SCM has at least one characteristic of being faster than the first memory in storing data, using less power to store data than the first memory, and providing a greater usable life than the first memory for repeatedly storing data in a same memory location. At least a portion of the SCM is allocated or reserved for use by a host, and logical addresses assigned to the SCM are mapped to device addresses of the first memory identifying locations for storing data in the first memory. The host is provided with an indication of the logical addresses assigned to the SCM to allow the host to retrieve data from and store data in the DSD or to directly access data using the logical addresses assigned to the SCM.