Seagate ST450MP0074 Savvio 15K SAS Product Manual - Page 74

66

Savvio 15K SAS Product Manual, Rev. B

9.5.2.4

Electrical TxRx connections

TxRx connections may be divided into TxRx connection segments. In a single TxRx connection individual

TxRx connection segments may be formed from differing media and materials, including traces on printed wir-

ing boards and optical fibers. This subclause applies only to TxRx connection segments that are formed from

electrically conductive media.

Each electrical TxRx connection segment shall comply with the impedance requirements of

table 21 for the

media from which they are formed. An equalizer network, if present, shall be part of the TxRx connection.

TxRx connections that are composed entirely of electrically conducting media shall be applied only to homoge-

nous ground applications (e.g., between devices within an enclosure or rack, or between enclosures intercon-

nected by a common ground return or ground plane).

9.5.2.4.1

Transmitter characteristics

The drive are D.C. coupled.

A combination of a zero-length test load and the transmitter compliance transfer function (TCTF) test load

methodology is used for the specification of transmitter characteristics. This methodology specifies the trans-

mitter signal at the test points on the required test loads. The transmitter

uses the same settings (e.g., pre-

emphasis, voltage swing) with both the zero-length test load and the TCTF test load. The signal specifications

at IR are met under each of these loading conditions.

The TCTF is the mathematical statement of the transfer function through which the transmitter shall be capable

of producing acceptable signals as defined by a receive mask. The transmission magnitude response of the

TCTF in dB is given by the following equation for 1.5 Gbps:

a

All times indicated for time domain reflectometer measurements are recorded times. Recorded times are twice the

transit time of the time domain reflectometer signal.

b

All measurements are made through mated connector pairs.

c

The media impedance measurement identifies the impedance mismatches present in the media when terminated in

its characteristic impedance. This measurement excludes mated connectors at both ends of the media, when

present, but includes any intermediate connectors or splices. The mated connectors measurement applies only to the

mated connector pair at each end, as applicable.

d

Where the media has an electrical length of > 4 ns the procedure detailed in SFF-8410, or an equivalent procedure,

shall be used to determine the impedance.

e

The receiver termination impedance specification applies to all receivers in a TxRx connection and covers all time

points between the connector nearest the receiver, the receiver, and the transmission line terminator. This

measurement shall be made from that connector.

f

At the time point corresponding to the connection of the receiver to the transmission line the input capacitance of the

receiver and its connection to the transmission line may cause the measured impedance to fall below the minimum

impedances specified in this table. The area of the impedance dip (amplitude as

ρ

, the reflection coefficient, and

duration in time) caused by this capacitance is the receiver termination time constant. The receiver time constant

shall not be greater than the values shown in this table. An approximate value for the receiver termination time

constant is given by the product of the amplitude of the dip (as

ρ

) and its width (in ps) measured at the half amplitude

point. The amplitude is defined as being the difference in the reflection coefficient between the reflection coefficient at

the nominal impedance and the reflection coefficient at the minimum impedance point. The value of the receiver

excess input capacitance is given by the following equation:

where (R0 || RR) is the parallel combination of the transmission line characteristic impedance and

termination resistance at the receiver.

g

The difference in measured impedance to ground on the plus and minus terminals on the interconnect, transmitter or

receiver, with a differential test signal applied to those terminals.

Table 21:

Impedance requirements (Sheet 2 of 2)

Requirement

Units

1.5 Gbps

3.0 Gbps

C

receiver termination time constant

R

0

RR

|

(

)

-----------------------------------------------------------------------------------------

=

Section	Page
Figure 1. Typical ST973451SS current profile 25	7
Figure 2. Typical ST936751SS current profile 26	7
Figure 3. ST973451SS (3 Gbit) DC current and power vs. input/output operations per second 27	7
Figure 4. ST973451SS (1.5 Gbit) DC current and power vs. input/output operations per second 27	7
Figure 5. ST936751SS (3 Gbit) DC current and power vs. input/output operations per second 28	7
Figure 6. ST936751SS (1.5 Gbit) DC current and power vs. input/output operations per second 28	7
Figure 7. Location of the HDA temperature check point 29	7
Figure 8. Recommended mounting 31	7
Figure 9. Mounting configuration dimensions 34	7
Figure 10. Physical interface 39	7
Figure 11. Air flow 40	7
Figure 12. Physical interface 54	7
Figure 13. SAS device plug dimensions 55	7
Figure 14. SAS device plug dimensions (detail) 56	7
Figure 15. SAS transmitters and receivers 58	7
Figure 16. Receive eye mask 60	7
Figure 17. Reveive tolerance eye mask 61	7
Figure 18. Sinusoidal jitter mask 62	7
Figure 19. Compliance interconnect test load 67	7
Figure 20. Zero-length test load 68	7
Figure 21. ISI loss example at 3.0 Gbps 68	7
Figure 22. ISI loss example at 1.5 Gbps 68	7
1.0 Scope	9
2.0 Applicable standards and reference documentation	11
2.1 Standards	11
2.1.1 Electromagnetic compatibility	11
2.1.1.1 Electromagnetic susceptibility	11
2.1.2 Electromagnetic compliance	12
2.1.3 European Union Restriction of Hazardous Substances (RoHS)	13
2.2 Reference documents	13
3.0 General description	15
3.1 Standard features	16
3.2 Media description	16
3.3 Performance	16
3.4 Reliability	17
3.5 Formatted capacities	17
3.6 Programmable drive capacity	17
3.7 Factory-installed accessories	17
3.8 Options	18
4.0 Performance characteristics	19
4.1 Internal drive characteristics	19
4.2 Seek performance characteristics	19
4.2.1 Access time (Gen 2.0 LP data)	19
4.2.2 Format command execution time	20
4.2.3 General performance characteristics	20
4.3 Start/stop time	21
4.4 Prefetch/multi-segmented cache control	21
4.5 Cache operation	21
4.5.1 Caching write data	22
4.5.2 Prefetch operation	22
5.0 Reliability specifications	23
5.1 Error rates	23
5.1.1 Recoverable Errors	23
5.1.2 Unrecoverable Errors	23
5.1.3 Seek errors	24
5.1.4 Interface errors	24
5.2 Reliability and service	24
5.2.1 Annualized Failure Rate (AFR) and Mean Time Between Failure (MTBF)	24
5.2.2 Preventive maintenance	24
5.2.3 Hot plugging the drive	24
5.2.4 S.M.A.R.T.	25
5.2.5 Thermal monitor	26
5.2.6 Drive Self Test (DST)	26
5.2.6.1 DST failure definition	27
5.2.6.2 Implementation	27
5.2.6.2.1 State of the drive prior to testing	27
5.2.6.2.2 Invoking DST	27
5.2.6.2.3 Short and extended tests	27
5.2.6.2.4 Log page entries	28
5.2.6.2.5 Abort	28
5.2.7 Product warranty	28
6.0 Physical/electrical specifications	31
6.1 AC power requirements	31
6.2 DC power requirements	31
6.2.1 Conducted noise immunity	33
6.2.2 Power sequencing	33
6.2.3 Current profiles	33
6.3 Power dissipation	35
6.4 Environmental limits	37
6.4.1 Temperature	37
6.4.2 Relative humidity	37
6.4.3 Effective altitude (sea level)	38
6.4.4 Shock and vibration	38
6.4.4.1 Shock	38
6.4.4.2 Vibration	40
6.4.5 Air cleanliness	40
6.4.6 Corrosive environment	40
6.4.7 Acoustics	41
6.4.8 Electromagnetic susceptibility	41
6.5 Mechanical specifications	42
7.0 Defect and error management	43
7.1 Drive internal defects/errors	43
7.2 Drive error recovery procedures	43
7.3 SAS system errors	44
7.4 Background Media Scan	45
7.5 Media Pre-Scan	45
7.6 Deferred Auto-Reallocation	45
7.7 Idle Read After Write	46
8.0 Installation	47
8.1 Drive orientation	47
8.2 Cooling	48
8.3 Drive mounting	49
8.4 Grounding	49
9.0 Interface requirements	51
9.1 SAS features	51
9.1.1 task management functions	51
9.1.2 Task management responses	51
9.2 Dual port support	52
9.3 SCSI commands supported	53
9.3.1 Inquiry data	57
9.3.2 Mode Sense data	57
9.4 Miscellaneous operating features and conditions	61
9.4.1 SAS physical interface	62
9.4.2 Physical characteristics	65
9.4.3 Connector requirements	65
9.4.4 Electrical description	65
9.4.5 Pin descriptions	65
9.4.6 SAS transmitters and receivers	66
9.4.7 Power	67
9.5 Signal characteristics	67
9.5.1 Ready LED Out	67
9.5.2 Differential signals	67
9.5.2.1 Eye masks	68
9.5.2.1.1 Eye masks overview	68
9.5.2.1.2 Receive eye mask	68
9.5.2.1.3 Jitter tolerance masks	69
9.5.2.2 Transmitter signal characteristics	70
9.5.2.3 Receiver signal characteristics	71
9.5.2.3.1 Jitter	72
9.5.2.3.2 Receiver jitter tolerance	72
9.5.2.3.3 Compliant jitter test pattern (CJTPAT)	72
9.5.2.3.4 Impedance specifications	73
9.5.2.4 Electrical TxRx connections	74
9.5.2.4.1 Transmitter characteristics	74
9.5.2.5 Receiver characteristics	77
10.0 Seagate Technology support services	79
Numerics	81
A	81
B	81
C	81
D	81
E	81
F	82
G	82
H	82
I	82
J	82
L	82
M	82
N	83
O	83
P	83
Q	83
R	83
S	83
T	84
U	84
V	84
W	84

Seagate ST450MP0074 Savvio 15K SAS Product Manual - Page 74

Electrical TxRx connections, 5.2.4.1, Transmitter characteristics, Table 21, Impedance

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