AMD SB600 - page 37

©2008 Advanced Micro Devices, Inc. SATA Registers (Device 18, Function 0)
AMD SB600 Register Reference Manual Proprietary Page 37
Port-N Command and Status - R - 32 bits [Mem_reg: ABAR + port offset + 18h]
Field Name Bits Default Description
Interface Communication
Control (ICC)
31:28 0h
RW
This field is used to control power management states of the
interface. If the Link layer is currently in the L_IDLE state,
writes to this field shall cause the HBA to initiate a transition
to the interface power management state requested. If the
Link layer is not currently in the L_IDLE state, writes to this
field shall have no effect.
Value Definition
Fh - 7h Reserved
6h Slumber: This shall cause the HBA to
request a transition of the interface to the
Slumber state. The SATA device may
reject the request and the interface shall
remain in its current state.
5h - 3h Reserved
2h Partial: This shall cause the HBA to
request a transition of the interface to the
Partial state. The SATA device may reject
the request and the interface shall remain
in its current state.
1h Active: This shall cause the HBA to
request a transition of the interface into the
active state.
0h No-Op / Idle: When software reads this
value, it indicates the HBA is ready to
accept a new interface control command,
although the transition to the previously
selected state may not yet have occurred.
When the system software writes a non-reserved value other
than No-Op (0h), the HBA shall perform the action and
update this field back to Idle (0h).
If software writes to this field to change the state to a state
the link is already in (i.e. interface is in the active state and a
request is made to go to the active state), the HBA shall take
no action and return this field to Idle. If the interface is in a
low power state and software wants to transition to a different
low power state, software must first bring the link to active
and then initiate the transition to the desired low power state.