Seagate ST9146652SS, ST973452SS, ST973352SS SAS-2 Specification compliance, Additional information

Table 16 defines the general interface characteristics.

Table 16: General interface characteristics

Characteristic	Units	1.5 Gbps	3.0 Gbps	6.0 Gbps
Bit rate (nominal)	Mbaud	1,500	3,000	6,000
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

12.6SAS-2 Specification compliance

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 6 Gbps 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 dur- ing the SNW-3 training gap. The DFE circuit can derive an optimal equalization characteristic to compen- sate 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.

12.7Additional information

Please contact your 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.

Savvio 15K.2 SAS Product Manual, Rev. E 63