APPLIANCES POWERED OVER SAS
Methods and structure for powering storage devices over a SAS interface. An exemplary system includes a storage device that includes a receptacle configured to receive a plug that communicates Serial Attached Small Computer Systems Interface compliant signals from a host system. The storage device also includes a microcontroller configured to detect a first power level on a power contact of the receptacle. The storage device further includes a circuit board configured to power up to the first power level via the microcontroller, to receive an inter-integrated circuit communication that indicates a second power level is available, and to power up to the second power level to sufficiently power a storage appliance.
1 . A storage device, comprising:
a receptacle configured to receive a plug that communicates Serial Attached Small Computer Systems Interface compliant signals from a host system;
a microcontroller configured to detect a first power level on a power contact of the receptacle; and
a circuit board configured to power up to the first power level via the microcontroller, to receive an inter-integrated circuit communication that indicates a second power level is available, and to power up to the second power level to sufficiently power a storage appliance.
2 . The storage device of claim 1 , wherein:
the inter-integrated circuit communication indicates that up to 30 watts is available from the host system.
3 . The storage device of claim 1 , wherein:
the plug comprises a High Density Mini Serial Attached Small Computer System Interface plug.
4 . The storage device of claim 1 , wherein:
the receptacle comprises a High Density Mini Serial Attached Small Computer System Interface plug.
5 . The storage device of claim 4 , wherein:
power is received on pins B 1 and D 1 of the receptacle.
6 . The storage device of claim 4 , wherein:
the inter-integrated circuit communication is received via pins C 1 and C 2 of the receptacle.
7 . The storage device of claim 1 , wherein:
the plug is a terminal end of a size 24 American Wire Gauge standard cable; and
the cable delivers up to 25 watts of power from the host system to the storage device to power the storage device from a distance of up to 60 meters.
8 . A method, comprising:
receiving, with a receptacle of a storage device, a plug that communicates Serial Attached Small Computer Systems Interface compliant signals from a host system;
detecting, with a microcontroller, a first power level on a power contact of the receptacle;
powering up a circuit board of the storage device to the first power level via the microcontroller;
receiving an inter-integrated circuit communication that indicates a second power level is available; and
powering-up the circuit board to the second power level to sufficiently power a storage appliance.
9 . The method of claim 8 , wherein:
the inter-integrated circuit communication indicates that up to 30 watts is available from the host system.
10 . The method of claim 8 , wherein:
the plug comprises a High Density Mini Serial Attached Small Computer System Interface plug.
11 . The method of claim 8 , wherein:
the receptacle comprises a High Density Mini Serial Attached Small Computer System Interface plug.
12 . The method of claim 11 , wherein:
power is received on pins B 1 and D 1 of the receptacle.
13 . The method of claim 11 , wherein:
the inter-integrated circuit communication is received via pins C 1 and C 2 of the receptacle.
14 . The method of claim 8 , wherein:
the plug is a terminal end of a size 24 American Wire Gauge standard cable; and
the cable delivers up to 25 watts of power from the host system to the storage device to power the storage device from a distance of up to 60 meters.