307013-003 Datasheet, PDF (540/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

SATA Controller Registers (D31:F2) (Desktop and Mobile Only)
12.3.2.11 PxSCTL — Port [3:0] Serial ATA Control Register (D31:F2)
Address Offset:
Default Value:
Port 0: ABAR + 12Ch
Attribute:
Port 1: ABAR + 1ACh (Desktop Only
Port 2: ABAR + 22Ch
Port 3: ABAR + 2ACh (Desktop Only)
00000004h
Size:
R/W, RO
32 bits
This is a 32-bit read-write register by which software controls SATA capabilities. Writes
to the SControl register result in an action being taken by the ICH7 or the interface.
Reads from the register return the last value written to it.
Bit
Description
31:20 Reserved
19:16
Port Multiplier Port (PMP) — RO. This field is not used by AHCI
NOTE: Port Multiplier not supported by Intel^® ICH7.
15:12 Select Power Management (SPM) — RO. This field is not used by AHCI
Interface Power Management Transitions Allowed (IPM) — R/W. Indicates which
power states the ICH7 is allowed to transition to:
11:8
Value
0h
1h
2h
3h
Description
No interface restrictions
Transitions to the PARTIAL state disabled
Transitions to the SLUMBER state disabled
Transitions to both PARTIAL and SLUMBER states disabled
All other values reserved
Speed Allowed (SPD) — R/W. Indicates the highest allowable speed of the interface.
This speed is limited by the CAP.ISS (ABAR+00h:bit 23:20) field.
Value Description
0h
No speed negotiation restrictions
1h
Limit speed negotiation to Generation 1 communication rate
7:4
2h
Limit speed negotiation to Generation 2 communication rate
All other values reserved
ICH7 Supports Generation 1 communication rates (1.5 Gb/sec) and Gen 2 rates (3.0
Gb/s).
ICH7 Mobile SKUs support Generation 1 communication rates (1.5 Gb/sec).
Device Detection Initialization (DET) — R/W. Controls the ICH7’s device detection
and interface initialization.
Value Description
0h
No device detection or initialization action requested
Perform interface communication initialization sequence to
1h
establish communication. This is functionally equivalent to a hard
reset and results in the interface being reset and communications
3:0
re-initialized
4h
Disable the Serial ATA interface and put Phy in offline mode
All other values reserved.
When this field is written to a 1h, the ICH7 initiates COMRESET and starts the
initialization process. When the initialization is complete, this field shall remain 1h until
set to another value by software.
This field may only be changed to 1h or 4h when PxCMD.ST is 0. Changing this field
while the ICH7 is running results in undefined behavior.
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Intel ^® ICH7 Family Datasheet