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Registers
1375
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Serial ATA (SATA) Controller
28.4.1 HBA Capabilities Register (CAP)
The HBA capabilities register (CAP) indicates basic capabilities of the DWC SATA AHCI to the driver
software. The CAP is shown in
and described in
Figure 28-1. HBA Capabilities Register (CAP)
31
30
29
28
27
26
25
24
23
20
19
18
17
16
S64A
SNCQ
SSNTF
SMPS
SSS
SALP
SAL
SCLO
ISS
SNZO
SAM
SPM
Rsvd
R-0
R-1
R-1
W/RO-0 W/RO-0
R-1
R-1
R-1
R-2h
R-0
R-1
R-1
R-0
15
14
13
12
8
7
6
5
4
0
PMD
SSC
PSC
NCS
CCCS
EMS
SXS
NP
R-1
R-1
R-1
R-1Fh
R-1
R-0
R-0
R-0
LEGEND: R/W = Read/Write; R = Read only; W/RO: written once after hard reset by firmware, then remain as read-only;
-
n
= value after reset
Table 28-5. HBA Capabilities Register (CAP) Field Descriptions
Bit
Field
Value
Description
31
S64A
0
Indicates Support for 64-Bit Addressing. The SATASS only supports 32-bit addressing so this bit is
always 0.
30
SNCQ
1
Supports Native Command Queuing. SATASS supports SATA native command queuing by handling
DMA Setup FIS natively.
29
SSNTF
1
Supports SNotification Register. SATASS supports P0SNTF (SNotification) register and its associated
functionality.
28
SMPS
0
Supports Mechanical Presence Switch. This bit is set by firmware when the platform supports a
mechanical presence switch for hot plug operation.
27
SSS
0
Supports Staggered Spin-Up. Only writable once after power up.
26
SALP
1
Supports Aggressive Link Power Management. SATASS supports auto-generating (Port-initiated) Link
Layer requests to the PARTIAL or SLUMBER power management states when there are no commands
to process.
25
SAL
1
Supports Activity LED.
24
SCLO
1
Supports Command List Override. Supports the P0CMD.CLO bit functionality for Port Multiplier devices
enumeration.
23-20
ISS
2h
Interface Speed Support. SATASS Supports 1.5 and 3 Gbps.
19
SNZO
0
Supports Non-Zero DMA Offsets. Not supported.
18
SAM
1
Supports AHCI Mode Only. SATASS supports AHCI mode only and does not support legacy, task-file
based register interface.
17
SPM
1
Supports Port Multiplier. SATASS supports command-based switching Port Multiplier on any of its
Ports.
16
Reserved
0
Reserved.
15
PMD
1
PIO Multiple DRQ Block. SATASS supports multiple DRQ block data transfers for the PIO command
protocol.
14
SSC
1
Slumber State Capable. SATASS supports transitions to the interface SLUMBER power management
state.
13
PSC
1
Partial State Capable. SATASS supports transitions to the interface PARTIAL power management
state.
12-8
NCS
1Fh
Number of Command Slots. SATASS supports 32 command slots per Port.
7
CCCS
1
Command Completion Coalescing Supported. SATASS supports command completion coalescing.
6
EMS
0
Enclosure Management Supported. Enclosure Management is not supported.
5
SXS
0
Supports External SATA.
4-0
NP
Number of Ports. Indicates the number of Ports supported by the SATSS.
0
1 Port
28.4.2 Global HBA Control Register (GHC)
The global HBA control register (GHC) provides various global functions for the SATASS. The GHC is
shown in
and described in