Seagate ST600MX0004 - 512E ユーザーズマニュアル

S

EAGATE 

E

NTERPRISE 

P

ERFORMANCE 

15K HDD 

AND 

E

NTERPRISE 

T

URBO 

SSHD SAS P

RODUCT 

M

ANUAL

, R

EV

. B

 

 59

  

The Ready LED Out signal is designed to pull down the cathode of an LED. The anode is attached to the proper +3.3 volt supply t hrough 

an appropriate current limiting resistor. The LED and the current limiting resistor are external to the drive. See Table 17 for the output 

characteristics of the LED drive signals.      

11.5.2 Differential signals
The drive SAS differential signals comply with the intra-enclosure (internal connector) requirements of the SAS standard.
Table 18 defines the general interface characteristics.

Seagate SAS-2 drives are entirely compatible with the latest SAS-2 Specification (T10/1760-D) Revision 16.

The most important characteristic of the SAS-2 drive at 6Gb/s is that the receiver is capable of adapting the equalizer to optimize the 

receive margins. The SAS-2 drive has two types of equalizers: 
1. A Decision Feedback Equalizer (DFE) which utilizes the standard SAS-2 training pattern transmitted during the SNW-3 training  gap. 

The DFE circuit can derive an optimal equalization characteristic to compensate for many of the receive losses in the system.

2. A Feed Forward Equalizer (FFE) optimized to provide balanced receive margins over a range of channels bounded by the best and  

worst case channels as defined by the relevant ANSI standard.

Please contact the Seagate representative for SAS electrical details, if required.

For more information about the Phy, Link, Transport, and Applications layers of the SAS interface, refer to the Seagate SAS Interface 

Manual, part number 100293071.

For more information about the SCSI commands used by Seagate SAS drives, refer to the Seagate SCSI Commands Reference Manual, 

part number 100293068.

LED off, high

0 V 

≤

 VOH 

≤

 3.6 V

-100 μA < I

OH

 < 100 μA

LED on, low

I

OL

 = 15 mA

0 

≤

 V

OL

 

≤

 0.225 V

Bit rate (nominal)

Mbaud

1500

3000

6000

Unit interval (UI)(nominal)

ps

666.6

333.3

166.6

Impedance (nominal, differential )

ohm

100

100

100

Transmitter transients, maximum

V

± 1.2

± 1.2

± 1.2

Receiver transients, maximum

V

± 1.2

± 1.2

± 1.2