Western Digital WD 2TB 3D NAND SATA III 2.5" Internal SSD (Retail) - Manual (Page 11)

The device can enter in to the SATA Partial and Slumber low-power modes through
DIPM. In DIPM, the device sends a request to the host to enter into Slumber mode
upon completion of any command.
The device also supports the SATA Device Sleep (DEVSLP) mode. For more
information, refer to the SATA revision 3.2 specification available at www.t13.org
Introduction
WD Blue 3D NAND SATA SSD
User Manual
6