Registers
1395
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Serial ATA (SATA) Controller
28.4.24 Port Command Register (P0CMD)
The port command register (P0CMD) contains bits controlling various Port functions. All read/write bits are
reset on Global reset. The P0CMD is shown in
and described in
Figure 28-24. Port Command Register (P0CMD)
31
28
27
26
25
24
23
22
21
20
19
18
17
16
ICC
ASP
ALPE
DLAE
ATAPI
Reserved
ESP
CPD
MPSP
HPCP
PMA
CPS
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-0
W/RO-0
W/RO-0
W/RO-0
W/RO-0
R/W-0
R-0
15
14
13
12
8
7
5
4
3
2
1
0
CR
FR
MPSS
CCS
Reserved
FRE
CLO
POD
SUD
ST
R-0
R-0
R-0
R-0
R-0
R/W-0
W-0
R/W-0
W/RO-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; W = Write; W/RO: written once after hard reset by firmware, then remain as read-only;
-
n
= value after reset
Table 28-28. Port Command Register (P0CMD) Field Descriptions
Bit
Field
Value
Description
31-28
ICC
0-Fh
Interface Communication Control. Controls power management states of the interface. If the Link layer
is currently in the L_IDLE state, writes to this bit field causes the Port 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 bit field have no effect.
When system software writes a nonreserved value other than No-Op (0), the Port performs the action
and updates this bit field back to Idle (0). If software writes to this bit field to change the state to a state
the link is already in (that is, interface is in the active state and a request is made to go to the active
state), the Port takes no action and returns this bit 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.
0
No-Op/ Idle: When software reads this value, it indicates the Port is ready to accept a new interface
control command, although the transition to the previously selected state may not yet have occurred.
1h
Active: Causes the Port to request a transition of the interface into the active state.
2h
Partial: Causes the Port to request a transition of the interface to the Partial state. The SATA device
may reject the request and the interface remains in its current state.
3h-5h
Reserved
6h
Slumber: Causes the Port to request a transition of the interface to the Slumber state. The SATA device
may reject the request and the interface remains in its current state.
7h-Fh
Reserved
27
ASP
Aggressive Slumber/Partial.
0
When cleared to 0 and P0CMD.ALPE = 1, the Port aggressively enters the PARTIAL state when it
clears the P0CI register, and the P0SACT register is cleared when it clears the P0SACT register and
P0CI is cleared.
1
When set to 1 and P0CMD.ALPE = 1, the Port aggressively enters the SLUBMER state when it clears
the P0CI register and the P0SACT register is cleared, or when it clears the P0SACT register and P0CI
is cleared.
26
ALPE
Aggressive Link Power Management Enable.
0
Aggressive power management state transition is disabled.
1
Port aggressively enters a lower link power state (PARTIAL or SLUMBER) based on the setting of the
P0CMD.ASP bit.
25
DLAE
0-1
Drive LED on ATAPI Enable. When set to 1, P0CMD.ATAPI = 1, and commands are active, the Port
asserts P0_act_led output.
24
ATAPI
0-1
Device is ATAPI. When set to 1, the connected device is an ATAPI device. This bit is used by the Port
to control whether or not to assert P0_act_led output when commands are active.
23-22
Reserved
0
Reserved.
21
ESP
External SATA Port. The ESP bit is mutually exclusive with the P0CMD.HPCP bit.
0
Ports signal only connector is not externally accessible.
1
Ports signal only connector is externally accessible. When set to 1, CAP.SXS is also set to 1.