AMD SB600 - page 35

AMD SB600 Register Reference Manual Proprietary Page 35

Port-N Command and Status - R - 32 bits [Mem_reg: ABAR + port offset + 18h]

Field Name Bits Default Description

Current Command Slot

(CCS)

12:8 00h This field is valid when P0CMD.ST is set to ‘1’ and shall be

set to the command slot value of the command that is

currently being issued by the HBA. When P0CMD.ST

transitions from ‘1’ to ‘0’, this field shall be reset to ‘0’. After

P0CMD.ST transitions from ‘0’ to ‘1’, the highest priority slot

to issue from next is command slot 0. After the first

command has been issued, the highest priority slot to issue

from next is P0CMD.CCS + 1. For example, after the HBA

has issued its first command, if CCS = 0h and P0CI is set to

3h, the next command that will be issued is from command

slot 1.

Mechanical Presence

Switch State (MPSS)

13 1b The MPSS bit reports the state of a mechanical presence

switch attached to this port. If CAP.SMPS is set to ‘1’ and the

mechanical presence switch is closed then this bit is cleared

to ‘0’. If CAP.SMPS is set to ‘1’ and the mechanical presence

switch is open then this bit is set to ‘1’. If CAP.SMPS is set to

‘0’ then this bit is cleared to ‘0’. Software should only use this

bit if both CAP.SMPS and P0CMD.MPSP are set to ‘1’.

FIS Receive Running

(FR)

14 0b When set, the FIS Receive DMA engine for the port is

running.

Command List Running

(CR)

15 0b When this bit is set, the command list DMA engine for the

port is running. See the AHCI state machine in section.

Cold Presence State

(CPS)

16 0b The CPS bit reports whether a device is currently detected on

this port via cold presence detection. If CPS is set to ‘1’, then

the HBA detects via cold presence that a device is attached

to this port. If CPS is cleared to ‘0’ , then the HBA detects via

cold presence that there is no device attached to this port.

Port Multiplier Attached

(PMA)

17 0b RW

This bit is read/write for HBAs that support a Port Multiplier

(CAP.SPM = ‘1’). This bit is read-only for HBAs that do not

support a port Multiplier (CAP.SPM = ‘0’). When set to ‘1’ by

software, a Port Multiplier is attached to the HBA for this port.

When cleared to ‘0’ by software, a Port Multiplier is not

attached to the HBA for this port. Software is responsible for

detecting whether a Port Multiplier is present; hardware does

not auto-detect the presence of a Port Multiplier.

Hot Plug Capable Port

(HPCP)

18 1b When set to ‘1’, indicates that this port’s signal and power

connectors are externally accessible via a joint signal and

power connector for blindmate device hot plug. When

cleared to ‘0’, indicates that this port’s signal and power

connectors are not externally accessible via a joint signal and

power connector.

Mechanical Presence

Switch Attached to Port

(MPSP)

19 0b If set to ‘1’, the platform supports an mechanical presence

switch attached to this port. If cleared to ‘0’, the platform

does not support a mechanical presence switch attached to

this port. When this bit is set to ‘1’, P0CMD.HPCP should

also be set to ‘1’.

Cold Presence Detection

(CPD)

20 0b If set to ‘1’, the platform supports cold presence detection on

this port. If cleared to ‘0’, the platform does not support cold

presence detection on this port. When this bit is set to ‘1’,

P0CMD.HPCP should also be set to ‘1’.

External SATA Port

(ESP)

21 0b When set to '1', indicates that this port’s signal connector is

externally accessible on a signal only connector. When set to

'1', CAP.SXS shall be set to '1'. When cleared to ‘0’, indicates

that this port’s signal connector is not externally accessible

on a signal only connector. ESP is mutually exclusive with

the HPCP bit in this register.

Reserved 23:22 Reserved