Systems and methods for handling write data access requests in data storage devices

Abstract

Embodiments of the invention are directed to systems and methods for optimizing handling of data access requests. In one embodiment, a data storage device including non-volatile memory and magnetic media includes a controller that defers writing data to the magnetic media by first writing to the non-volatile memory and reporting to the host a write complete status. However, in cases where the non-volatile memory includes Multi-Level Cell (MLC) memory, if the write data is to be written to an upper page of an MLC cell, a backup power source such as a capacitor may be needed to avoid the paired page corruption problem. Embodiments of the invention avoid the problem without the use of a backup power source by writing deferred write data to a portion of the MLC memory that is operating in Single-Level Cell (SLC) mode, i.e., only the lower pages of the memory cells are written.