Method and apparatus of automatic power management control for serial ATA device directly attached to SAS/SATA host controller

An apparatus, comprising:

• means for determining whether a Serial ATA device is directly attached to a SAS/SATA host controller without using a SAS expander;
• a counter, communicatively coupled to said means for determining, for counting idle time of a Serial ATA interface including said Serial ATA device and said SAS/SATA host controller when said Serial ATA device is directly attached to said SAS/SATA host controller;
• a first programmable register holding a first value, said first programmable register communicatively coupled to said counter;
• a second programmable register holding a second value, said second programmable register communicatively coupled to said counter;
• automatic power management circuitry communicatively coupled to said Serial ATA interface;
• and
• a third programmable register programmed based on input clock to determine frequency of said counter,
• wherein said automatic power management circuitry issues a request for Partial power state to a physical layer of said Serial ATA interface when a value of said counter is equal to said first value, and issues a request for Slumber power state to a physical layer of said Serial ATA interface when a value of said counter is equal to said second value.