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Cheetah NS SAS Product Manual, Rev. B

13

4.4

Prefetch/multi-segmented cache control

The drive provides a prefetch (read look-ahead) and multi-segmented cache control algorithms that in many 
cases can enhance system performance. Cache refers to the drive buffer storage space when it is used in 
cache operations. To select this feature, the host sends the Mode Select command with the proper values in 
the applicable bytes in page 08h. Prefetch and cache operations are independent features from the standpoint 
that each is enabled and disabled independently using the Mode Select command; however, in actual opera-
tion, the prefetch feature overlaps cache operation somewhat as described in sections 4.5.1 and 4.5.2. 

All default cache and prefetch mode parameter values (Mode Page 08h) for standard OEM versions of this 
drive family are given in Section 9.3.2.1.

4.5

Cache operation

Note.

Refer to the SAS Interface Manual for more detail concerning the cache bits.

Of the 16 Mbytes physical buffer space in the drive, approximately 13,000 kbytes can be used as a cache. The 
buffer is divided into logical segments from which data is read and to which data is written.

The drive keeps track of the logical block addresses of the data stored in each segment of the buffer. If the 
cache is enabled (see RCD bit in the SAS Interface Manual ), data requested by the host with a read command 
is retrieved from the buffer, if possible, before any disk access is initiated. If cache operation is not enabled, the 
buffer is still used, but only as circular buffer segments during disk medium read operations (disregarding 
Prefetch operation for the moment). That is, the drive does not check in the buffer segments for the requested 
read data, but goes directly to the medium to retrieve it. The retrieved data merely passes through some buffer 
segment on the way to the host. All data transfers to the host are in accordance with buffer-full ratio rules. See 
the explanation provided with the information about Mode Page 02h (disconnect/reconnect control) in the SAS 
Interface Manual
.

The following is a simplified description of the prefetch/cache operation: 

Case A—read command is received and all of the requested logical blocks are already in the cache: 

1.

Drive transfers the requested logical blocks to the initiator.

Case B—A Read command requests data, and at least one requested logical block is not in any segment of 
the cache:

1.

The drive fetches the requested logical blocks from the disk and transfers them into a segment, and then 
from there to the host in accordance with the Mode Select Disconnect/Reconnect parameters, page 02h.

2.

If the prefetch feature is enabled, refer to section 4.5.2 for operation from this point.

Each cache segment is actually a self-contained circular buffer whose length is an integer number of logical 
blocks. The drive dynamically creates and removes segments based on the workload. The wrap-around capa-
bility of the individual segments greatly enhances the cache’s overall performance.

Note.

The size of each segment is not reported by Mode Sense command page 08h, bytes 14 and 15. 
The value 0XFFFF is always reported regardless of the actual size of the segment. Sending a size 
specification using the Mode Select command (bytes 14 and 15) does not set up a new segment 
size. If the STRICT bit in Mode page 00h (byte 2, bit 1) is set to one, the drive responds as it does 
for any attempt to change an unchangeable parameter.

4.5.1

Caching write data 

Write caching is a write operation by the drive that makes use of a drive buffer storage area where the data to 
be written to the medium is stored while the drive performs the Write command. 

Содержание Cheetah NS SAS ST3400755SS

Страница 1: ...Product Manual Cheetah NS SAS 100453994 Rev B August 2007 ST3400755SS ...

Страница 2: ...mpanies in the United States and or other countries All other trademarks or registered trademarks are the property of their respective own ers One gigabyte or GB equals one billion bytes when referring to hard drive capacity Accessible capacity may vary depending on operating environment and formatting Quantitative usage examples for various applications are for illustrative purposes Actual quanti...

Страница 3: ... 3 Start stop time 12 4 4 Prefetch multi segmented cache control 13 4 5 Cache operation 13 4 5 1 Caching write data 13 4 5 2 Prefetch operation 14 5 0 Reliability specifications 15 5 1 Error rates 15 5 1 1 Recoverable Errors 15 5 1 2 Unrecoverable Errors 15 5 1 3 Seek errors 16 5 1 4 Interface errors 16 5 2 Reliability and service 16 5 2 1 Annualized Failure Rate AFR and Mean Time Between Failures...

Страница 4: ...edia Pre Scan 35 7 6 Deferred Auto Reallocation 36 7 7 Idle Read After Write 36 8 0 Installation 37 8 1 Drive orientation 37 8 2 Cooling 38 8 3 Drive mounting 39 8 4 Grounding 39 9 0 Interface requirements 41 9 1 SAS features 41 9 1 1 task management functions 41 9 1 2 task management responses 41 9 2 Dual port support 42 9 3 SCSI commands supported 43 9 3 1 Inquiry data 47 9 3 2 Mode Sense data 4...

Страница 5: ...gure 5 Physical dimensions 31 Figure 6 Physical interface 37 Figure 7 Air flow 38 Figure 8 Physical interface 51 Figure 9 SAS connector dimensions 52 Figure 10 SAS connector dimensions 53 Figure 11 SAS transmitters and receivers 55 Figure 12 Receive eye mask 57 Figure 13 Receive tolerance eye mask 57 Figure 14 Sinusoidal jitter mask 58 Figure 15 Compliance interconnect test load 63 Figure 16 Zero ...

Страница 6: ...2 Cheetah NS SAS Product Manual Rev B ...

Страница 7: ...ology LLC Cheetah NS SAS Serial Attached SCSI disk drives Cheetah drives support the SAS Protocol specifications to the extent described in this manual The SAS Inter face Manual part number 100293071 describes the general SAS characteristics of Cheetah NS and other Seagate SAS drives ...

Страница 8: ...2 Cheetah NS SAS Product Manual Rev B ...

Страница 9: ...nclosure prior to use The drive is supplied as a subassembly and is not subject to Subpart B of Part 15 of the FCC Rules and Regulations nor the Radio Interference Regulations of the Canadian Department of Communications The design characteristics of the drive serve to minimize radiation when installed in an enclosure that provides reasonable shielding The drive is capable of meeting the Class B l...

Страница 10: ...equirements of the Electromagnetic Compatibility Directive 89 336 EEC of 03 May 1989 as amended by Directive 92 31 EEC of 28 April 1992 and Directive 93 68 EEC of 22 July 1993 Australian C Tick If this model has the C Tick Marking it complies with the Australia New Zealand Standard AS NZS3548 1995 and meets the Electromagnetic Compatibility EMC Framework requirements of Australia s Spectrum Man ag...

Страница 11: ...ttached SCSI SAS Standard T10 1562 D ISO IEC 14776 xxx SCSI Architecure Model 3 SAM 3 Standard T10 1561 D ISO IEC 14776 xxx SCSI Primary Commands 3 SPC 3 Standard T10 1416 D ISO IEC 14776 xxx SCSI Block Commands 2 SBC 2 Standard T10 1417 D ANSI Small Computer System Interface SCSI Documents X3 270 1996 SCSI 3 Architecture Model Specification for Acoustic Test Requirement and Procedures Seagate par...

Страница 12: ...6 Cheetah NS SAS Product Manual Rev B ...

Страница 13: ...with either SAS or SATA hard disk drives This allows you to continue to leverage your existing investment in SCSI while gaining a 3Gb s serial data transfer rate The head and disk assembly HDA is sealed at the factory Air recirculates within the HDA through a non replaceable filter to maintain a contamination free HDA environment Note Never disassemble the HDA and do not attempt to service items i...

Страница 14: ...design Automatic shipping lock Self diagnostics performed when power is applied to the drive Zone bit recording ZBR Vertical horizontal or top down mounting Dynamic spindle brake 16 Mbyte data buffer see Section 4 5 Drive Self Test DST Background Media Scan BGMS Power Save 3 2 Media description The media used on the drive has an aluminum substrate coated with a thin film magnetic material overcoat...

Страница 15: ...ermine if the extra capacity potential is useful or whether their assurance of backward and for ward compatibility takes precedence 3 6 Programmable drive capacity Using the Mode Select command the drive can change its capacity to something less than maximum See the Mode Select 6 parameter list table in the SAS Interface Manual part number 100293071 A value of zero in the Number of Blocks field in...

Страница 16: ...10 Cheetah NS SAS Product Manual Rev B ...

Страница 17: ...zone Disk rotation speed 10k rpm Avg rotational latency 2 98 msec One Gbyte equals one billion bytes when referring to hard drive capacity Accessible capacity may vary depending on operating environment and formatting 4 2 Seek performance See Section 9 4 1 SAS physical interface on page 51 and the SAS Interface Manual part number 100293071 for additional timing details 4 2 1 Access time Not Includ...

Страница 18: ...ter receiving a NOTIFY ENABLE SPINUP primitive through either port the drive becomes ready for normal operations within 30 seconds excluding the error recovery procedure If the drive receives a START STOP UNIT command with the START bit and IMMED bit equal to 1 and does not receive a NOTIFY ENABLE SPINUP primitive within 5 seconds the drive fails the START STOP UNIT command The START STOP UNIT com...

Страница 19: ...oes directly to the medium to retrieve it The retrieved data merely passes through some buffer segment on the way to the host All data transfers to the host are in accordance with buffer full ratio rules See the explanation provided with the information about Mode Page 02h disconnect reconnect control in the SAS Interface Manual The following is a simplified description of the prefetch cache opera...

Страница 20: ... an error occurs while writing the data to the medium and Good status has already been returned a deferred error will be gen erated The Synchronize Cache command may be used to force the drive to write all cached write data to the medium Upon completion of a Synchronize Cache command all data received from previous write commands will have been written to the medium Table 9 3 2 1 shows the mode de...

Страница 21: ...ough ECC on the fly is not considered for purposes of recov ered error specifications Recovered Data error rate is determined using read bits transferred for recoverable errors occurring during a read and using write bits transferred for recoverable errors occurring during a write 5 1 2 Unrecoverable Errors Unrecoverable Data Errors Sense Key 03h are specified at less than 1 sector in error per 10...

Страница 22: ...ion 6 4 1 may increase the AFR decrease the MTBF AFR and MTBF statistics are poplulation statistics that are not relevant to individual units AFR and MTBF specifications are based on the following assumptions for Enterprise Storage System environments 8 760 power on hours per year 250 average on off cycles per year Operating at nominal voltages System provides adequate cooling to ensure the case t...

Страница 23: ...gging process occurs To accomplish this issue a Log Sense command to log page 0x3E This allows you to control when S M A R T interruptions occur Forcing S M A R T with the RTZ command resets the timer Performance impact S M A R T attribute data is saved to the disk so that the events that caused a predictive failure can be recre ated The drive measures and saves parameters once every two hours sub...

Страница 24: ...rface when the tem perature exceeds a set threshold The temperature is measured at power up and then at ten minute intervals after power up The thermal monitor system generates a warning code of 01 0B01 when the temperature exceeds the speci fied limit in compliance with the SCSI standard The drive temperature is reported in the FRU code field of mode sense data You can use this information to det...

Страница 25: ...es are exhausted Write error after retries are exhausted Recovered errors will not be reported as diagnostic failures 5 2 7 2 Implementation This section provides all of the information necessary to implement the DST function on this drive 5 2 7 2 1 State of the drive prior to testing The drive must be in a ready state before issuing the Send Diagnostic command There are multiple reasons why a dri...

Страница 26: ...nction Code field is set to the same value as sent in the DST command 2 The Self Test Results Value field is set to Fh 3 The drive will store the log page to non volatile memory After a self test is complete or has been aborted the drive updates the Self Test Results Value field in its Self Test Results Log page in non volatile memory The host may use Log Sense to read the results from up to the l...

Страница 27: ...g or shipping a drive use only a Seagate approved container Keep your original box Seagate approved containers are easily identified by the Seagate Approved Package label Shipping a drive in a non approved container voids the drive warranty Seagate repair centers may refuse receipt of components improperly packaged or obviously damaged in tran sit Contact your authorized Seagate distributor to pur...

Страница 28: ...22 Cheetah NS SAS Product Manual Rev B ...

Страница 29: ...efore reaching 10 000 RPM The 5 must be maintained after the drive signifies that its power up sequence has been completed and that the drive is able to accept selection by the host initiator 3 See 12V current profile in Figure 19 4 This condition occurs after OOB and Speed Negotiation completes but before the drive has received the Notify Spinup primitive Table 2 ST3400755SS DC power requirements...

Страница 30: ...owered on simultaneously the peak starting current must be available to each device 4 Parameters other than spindle start are measured after a 10 minute warm up 5 No terminator power 6 2 1 Conducted noise immunity Noise is specified as a periodic and random distribution of frequencies covering a band from DC to 10 MHz Maximum allowed noise values given below are peak to peak measurements and apply...

Страница 31: ...O rate for a drive in your system on the horizontal axis and read the corresponding 5 volt current 12 volt current and total watts on the vertical axis To calculate BTUs per hour multiply watts by 3 4123 Figure 20 ST3400755SS 3 Gbit DC current and power vs input output operations per second ST3400755SS CURRENT POWER vs THROUGHPUT SAS 3 0GB Random 8 Block Reads 0 000 0 200 0 400 0 600 0 800 1 000 1...

Страница 32: ...R Provided the HDA case temperatures limits are met the drive meets all specifications over a 41 F to 131 F 5 C to 55 C drive ambient temperature range with a maximum temperature gradient of 36 F 20 C per hour Air flow may be needed in the drive enclosure to keep within this range see Section 8 3 Operation at HDA case temperatures outside this range may adversely affect the drives ability to meet ...

Страница 33: ...ding 25 Gs at a maximum duration of 2 msec half sinewave Shock may be applied in the X Y or Z axis b Operating abnormal Equipment as installed for normal operation does not incur physical damage while subjected to intermit tent shock not exceeding 40 Gs at a maximum duration of 11 msec half sinewave Shock occurring at abnormal levels may promote degraded operational performance during the abnormal...

Страница 34: ...ged in single or multipacks with a gross weight of 20 pounds 8 95 kg or less by Seagate for general freight shipment shall withstand a drop test from 48 inches 1 070 mm against a concrete floor or equivalent Figure 22 Recommended mounting Package size Packaged product weight Drop height 600 cu in 9 800 cu cm Any 60 in 1524 mm 600 1800 cu in 9 800 19 700 cu cm 0 20 lb 0 to 9 1 kg 48 in 1219 mm 1800...

Страница 35: ...ine 0 5 octave min Vibration may be applied in the X Y or Z axis 6 4 5 Acoustics Sound power during idle mode shall be 3 6 bels typical when measured to ISO 7779 specification Sound power while operating shall be 4 0 bels typical when measured to ISO 7779 specification There will not be any discrete tones more than 10 dB above the masking noise on typical drives when mea sured according to Seagate...

Страница 36: ... Chromium PBB and PBDE in electronic products effective July 2006 This drive is manufactured with components and materials that comply with the RoHS Directive 6 4 9 China Restriction of Hazardous Substances RoHS Directive This product has an Environmental Protection Use Period EPUP of 20 years The following table contains information mandated by China s Marking Requirements for Control of Pollutio...

Страница 37: ...8 MAX 2X 20 14 2X 793 6 35 250 24 00 945 2X 28 45 2X 1 120 2X 70 05 2X 2 758 122 00 4 803 2X 130 05 2X 5 120 0 36 014 146 99 MAX 5 787 MAX 131 17 5 164 85 60 3 370 41 15 1 620 2X 29 21 2X 1 150 1 45 057 3 17 125 20 14 793 50 80 2 000 101 60 25 4 000 010 2X 100 13 2X 3 942 98 42 3 875 20 68 814 33 40 1 315 0 76 030 0 13 005 0 13 005 3 50 38 138 015 0 25 010 0 99 039 0 41 016 36 37 1 432 4 57 MIN BL...

Страница 38: ...32 Cheetah NS SAS Product Manual Rev B ...

Страница 39: ...ist is not altered after factory formatting Locations of defects found and reallocated during error recovery procedures after drive shipment are listed in the G list defects growth list The P and G lists may be referenced by the initiator using the Read Defect Data command Details of the SCSI commands supported by the drive are described in the SAS Interface Manual Also more information on the dri...

Страница 40: ...nrecov ered error rate which may exceed the value given in this product manual A setting of zero 0 will result in the drive not performing error recovery For example suppose the read write recovery page has the RC bit set to 0 read retry count set to 4 and the recovery time limit field Mode Sense page 01 bytes 10 and 11 set to FF FF hex maximum A four LBA Read command is allowed to take up to 253 ...

Страница 41: ... the Start time after idle to 5ms all subsequent scans begin after 500ms of idle time Other features that normally use idle time to function will function normally because BMS functions for bursts of 800ms and then suspends activity for 100ms to allow other background functions to operate BMS interrupts immediately to service host commands from the interface bus while performing reads BMS will com...

Страница 42: ... write command to rewrite the data DAR is most effective when AWRE and ARRE are enabled this is the default setting from the Seagate factory With AWRE and ARRE disabled DAR is unable to reallocate the failing location and will report an error sense code indicating that a write command is being attempted to a previously failing location 7 7 Idle Read After Write Idle Read After Write IRAW utilizes ...

Страница 43: ...e drive using high quality cables is acceptable as long as the I O cable length does not exceed 4 meters 13 1 feet Slide the carrier or tray into the appropriate bay in your host system using the instructions provided by the host system This connects the drive directly to your system s SAS connector The SAS connector is normally located on a SAS backpanel See Section 9 4 1 for additional informati...

Страница 44: ...d in Section 6 4 1 If forced air is necessary possible air flow patterns are shown in Figure 25 The air flow patterns are created by fans either forcing or drawing air as shown in the illustrations Conduction convection or other forced air flow patterns are acceptable as long as the temperature measurement guidelines of Section 6 4 1 are met Figure 25 Air flow Above unit Under unit Note Air flows ...

Страница 45: ...to 5 25 inch adapter frame verify with Seagate Technology that the drive can meet the shock and vibration specifications given herein while mounted in such an adapter frame Adapter frames that are available may not have a mechanical structure capable of mounting the drive so that it can meet the shock and vibration specifications listed in this manual 8 4 Grounding Signal ground PCBA and HDA groun...

Страница 46: ...40 Cheetah NS SAS Product Manual Rev B ...

Страница 47: ...t functions Table 4 lists the SAS task management functions supported 9 1 2 task management responses Table 5 lists the SAS response codes returned for task management functions supported Table 4 SAS task management functions supported Task name Supported Abort Task Yes Clear ACA Yes Clear task set Yes Abort task set Yes Logical Unit Reset Yes Query Task Yes Table 5 Task management response codes ...

Страница 48: ...ed negotiation it indicates the only sup ported speed is the speed selected by the first port If the first port to complete speed negotiation looses sync before the second port completes speed negotiation both ports revert back to the power on condition of allow ing either link rate 1 5 or 3 0 Gbits sec Subject to buffer availability the Cheetah drives support Concurrent port transfers The drive s...

Страница 49: ...orted Y IMMED bit supported Y VS vendor specific N Inquiry 12h Y Date Code page C1h Y Device Behavior page C3h Y Firmware Numbers page C0h Y Implemented Operating Def page 81h Y Jumper Settings page C2h Y Supported Vital Product Data page 00h Y Unit Serial Number page 80h Y Lock unlock cache 36h N Log Select 4Ch Y PCR bit Y DU bit N DS bit Y TSD bit Y ETC bit N TMC bit N LP bit N Log Sense 4Dh Y A...

Страница 50: ...ct Reconnect 02h Y Error Recovery page 01h Y Format page 03h Y Information Exceptions Control page 1Ch Y Background Scan mode subpage 01h Y Notch and Partition Page 0Ch N Protocol Specific Port page 19h Y Power Condition page 1Ah Y Rigid Disk Drive Geometry page 04h Y Unit Attention page 00h Y Verify Error Recovery page 07h Y Xor Control page 10h N Mode Sense 10 same pages as Mode Sense 1Ah 5Ah Y ...

Страница 51: ... Search Data Equal 31h N Search Data High 30h N Search Data Low 32h N Seek 0Bh Y Seek Extended 2Bh Y Send Diagnostics 1Dh Y Supported Diagnostics pages 00h Y Translate page 40h Y Set Limits 33h N Start Unit Stop Unit spindle ceases rotating 1Bh Y Synchronize Cache 35h Y Test Unit Ready 00h Y Verify 2Fh Y BYTCHK bit Y Write 0Ah Y Write and Verify 2Eh Y DPO bit Y Write Buffer modes 0 2 supported 3Bh...

Страница 52: ...usually makes the drive inoperable 3 Reference Mode Sense command 1Ah for mode pages supported 4 Y Yes Command is supported N No Command is not supported A Support is available on special request FUA bit Y Write Long 3Fh Y Write Same 41h Y PBdata N LBdata N XDRead 52h N XDWrite 50h N XPWrite 51h N Table 6 Commands supported by Cheetah NS SAS family drives continued Command name Command code Suppor...

Страница 53: ... saved values where the values are change able 2 Saved values Saved values are stored on the drive s media using a Mode Select command Only parameter values that are allowed to be changed can be changed by this method Parameters in the saved values list that are not changeable by the Mode Select command get their values from default values storage When power is applied to the drive it takes saved ...

Страница 54: ...able values for Mode page 81 Note in columns 5 and 6 bytes 04 and 05 there is 00h which indicates that in bytes 04 and 05 none of the bits are changeable Note also that bytes 06 07 09 10 and 11 are not changeable because those fields are all zeros In byte 02 hex value FF equates to the binary pattern 11111111 If there is a zero in any bit position in the field it means that bit is not changeable S...

Страница 55: ...0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 DEF 87 0a 00 0b ff 00 00 00 00 00 ff ff CHG 87 0a 0f ff 00 00 00 00 00 00 ff ff DEF 88 12 14 00 ff ff 00 00 ff ff ff ff 80 20 00 00 00 00 00 00 CHG 88 12 a5 00 00 00 ff ff ff ff 00 00 20 00 00 00 00 00 00 00 DEF 8a 0a 02 00 00 00 00 00 00 00 15 fa CHG 8a 0a 03 f0 00 00 00 00 00 00 00 00 DEF 18 06 00 00 00 00 00 00 CHG 18 06 00 00 00 00 00 00 ...

Страница 56: ... N Synchronized locked spindle operation Y Segmented caching N Zero latency read Y Queue tagging up to 128 queue tags supported Y Deferred error handling Y Parameter rounding controlled by Round bit in Mode Select page 0 Y Reporting actual retry count in Extended Sense bytes 15 16 and 17 N Adaptive caching Y SMP 1 in Mode Select command needed to save RPL and rotational offset bytes Table 9 Miscel...

Страница 57: ...ice connector J1 Figures 27 and 28 provide the dimensions of the SAS device Details of the physical electrical and logical characteristics are provided within this section The operational aspects of Seagate s SAS drives are provided in the SAS Interface Manual Figure 26 Physical interface SAS Interface connector ...

Страница 58: ... 27 6X 1 27 14X 15 875 0 35MIN 15 875 33 43 0 05 B 4 90 0 08 0 84 0 05 22X 0 15 B P15 P1 S7 S1 SEE Detail1 0 30 0 05 4X 4 00 0 08 0 15 D 0 30 0 05 2X 41 13 0 15 B B C C A A 0 20 B 42 73 REF C OF DATUM D L 1 10 R0 30 0 08 4X 2 00 3X 5 08 0 45 0 03 7X 0 10 M E 4 65 0 80 6X 7 62 5 92 0 52 0 08 x 45 ...

Страница 59: ...urer for mating part information The SAS device connector is illustrated in Figures 27 and 28 6 10 Detail A 0 30 0 05 x 45 5X 0 40 0 05 X 45 3X CORING ALLOWED IN THIS AREA 2 25 0 05 4 85 0 05 0 10 B E S14 S8 4 40 0 15 SEE Detail 2 3 90 0 15 SECTION A A SECTION C C A 0 35 0 05 45 R0 30 0 08 C 1 95 0 08 0 08 0 05 1 23 0 05 0 08 0 05 Detail 2 CONTACT SURFACE FLUSH TO DATUM A 0 03 65 30 1 90 0 08 SECT...

Страница 60: ...ugging NC No connection in the drive Pin Signal name Signal type Pin Signal name Signal type S1 Port A Ground P1 NC reserved 3 3Volts S2 Port A_in Diff input pair P2 NC reserved 3 3Volts S3 Port A_in P3 NC reserved 3 3Volts S4 Port A Ground P4 Ground S5 Port A_out Diff output pair P5 Ground S6 Port A_out P6 Ground S7 Port A Ground P7 5 Volts charge S8 Port B Ground P8 5 Volts S9 Port B_in Diff inp...

Страница 61: ...rn current must be distributed as evenly as possible among the pins Current to the drive through the long power pins may be limited by the system to reduce inrush current to the drive during hot plugging 9 5 Signal characteristics This section describes the electrical signal characteristics of the drive s input and output signals See Table 10 for signal type and signal name information 9 5 1 Ready...

Страница 62: ...s 9 5 2 1 Eye masks 9 5 2 1 1 Eye masks overview The eye masks are graphical representations of the voltage and time limits on the signal at the compliance point The time values between X1 and 1 X1 cover all but 10 12 of the jitter population The random content of the total jitter population has a range of 7 standard deviations Table 12 LED drive signal State Test condition Output voltage LED off ...

Страница 63: ...lk are taken into account 9 5 2 1 3 Jitter tolerance masks Figure 31 describes the receive tolerance eye masks and is constructed using the X2 and Z2 values given in table 16 X1OP is half the value for total jitter intable 16 and X1TOL is half the value for total jitter in table 17 for jitter frequencies above bit rate 1 667 Figure 31 Receive tolerance eye mask Absolute amplitude in V Z1 Z2 0 V Z1...

Страница 64: ... Z1OP X1OP and X2OP are the values in table 15 for Z1 X1 and X2 The X1 points in the receive tolerance masks are greater than the X1 points in the receive masks due to the addition of sinusoidal jitter Figure 32 defines the sinusoidal jitter mask Figure 32 Sinusoidal jitter mask Z1TOL Z1OPx X2OP 0 5 xadditional sinusoidal jitter X1OP X2OP X1OP FNOM 25 000 FNOM 1 667 Sinusoidal jitter frequency log...

Страница 65: ...e transition with a repeating 0101b pattern on the physical link The same stable trigger coherent to the data stream shall be used for both the Tx and Tx signals Skew is defined as the time difference between the means of the midpoint crossing times of the Tx signal and the Tx signal c The transmitter off voltage is the maximum A C voltage measured at compliance points when the transmitter is unpo...

Страница 66: ...he same stable trigger coherent to the data stream shall be used for both the Rx and Rx signals Skew is defined as the time difference between the means of the midpoint crossing times of the Rx signal and the Rx signal e Near end crosstalk is the unwanted signal amplitude at receiver terminals DR CR and XR coupled from signals and noise sources other than the desired signal Refer to SFF 8410 Table...

Страница 67: ...p c Sinusoidal swept frequency 900 kHz to 5 MHz d Sinusoidal swept frequency 1 800 kHz to 5 MHz e No value is given for random jitter For compliance with this standard the actual random jitter amplitude shall be the value that brings total jitter to the stated value at a probability of 10 12 The additional 0 1 UI of sinusoidal jitter is added to ensure the receiver has sufficient operating margin ...

Страница 68: ...asurement 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 th...

Страница 69: ...signal frequency in hertz The TCTF is used to specify the requirements on transmitters that may or may not incorporate pre emphasis or other forms of compensation A compliance interconnect is any physical interconnect with loss equal to or greater than that of the TCTF at the above frequencies that also meets the ISI loss requirements shown in fig ure 35 and figure 36 Compliance with the TCTF test...

Страница 70: ... Gbps Figure 36 ISI loss example at 1 5 Gbps Tx Tx 10 nF 50 ohm 50 ohm Probe points SASinternal connector 10 nF ISIloss 3 9dB 10 9dB Frequency GHz Samplecom pliance interconnect 0 3 0 1 5 0 3 S21 dB Complianceinterconnect magnituderesponse and ISIloss example for 3 0 Gbps ISIloss 2 0 dB Frequency GHz Sam ple com pliance interconnect 0 1 5 0 75 0 15 S21 dB Compliance interconnect m agnitude respons...

Страница 71: ... objective when the signal at a receiving phy has the addi tional sinusoidal jitter present that is specified in table 17 and the common mode signal VCM over frequency range FCM as specified in table 13 The jitter tolerance is shown in Figure 32 for all Rx compliance points in a TxRx connection The figure given assumes that any external interference occurs prior to the point at which the test is a...

Страница 72: ...66 Cheetah NS SAS Product Manual Rev B ...

Страница 73: ... with product information program benefits and sales tools You may register for customized communications that are not available on the web These communications contain product launch EOL pricing promotions and other channel related information To learn more about the benefits or to register go to spp seagate com any time from anywhere in the world Seagate Service Centers Presales Support Our Pres...

Страница 74: ...ilable on a global basis for the return of defective products Contact your customer support representative for the location nearest you USA Canada Latin America support services For an extensive list of telephone numbers to technical support presales and warranty service in USA Canada Latin America including business hours go to the Contact Us page on www seagate com Global Customer Support Presal...

Страница 75: ...nications 3 capacity unformatted 11 check condition status 50 chemical pollutants 29 China RoHS directive 30 class B limit 3 clear ACA function 41 clear task set function 41 commands supported 43 condensation 27 condition met good status 50 connector illustrated 53 requirements 53 continuous vibration 29 cooling 38 corrosive environment 29 CRC error 16 Current profiles 24 customer service 21 D DAR...

Страница 76: ...atus 50 internal data rate 11 internal defects errors 33 internal drive characteristics 11 IRAW 36 J jumpers 37 L latency average rotational 11 logical block address 13 logical block reallocation scheme 8 logical block size 8 12 logical segments 13 M maintenance 15 maximum delayed motor start 23 maximum start current 23 media description 8 Media Pre Scan 35 miscellaneous feature support Adaptive c...

Страница 77: ...commended mounting 28 Recoverable Errors 15 recovered media data 15 reference documents 5 relative humidity 27 reliability 8 specifications 15 reliability and service 16 repair and return information 21 reporting actual retry count 50 reservation conflict status 50 resonance 27 return information 21 RoHS 30 rotation speed 11 S safety 3 SAS interface 54 physical interface 51 task management functio...

Страница 78: ...t supported 05 41 Function reject 04 41 task set full status 50 technical support services 67 temperature 26 38 limits 26 non operating 26 regulation 3 See also cooling terminate task function 41 terminators 37 tracks per inch 11 tracks per surface 11 transmitters 55 transporting the drive 21 U unformatted 9 Unrecoverable Errors 15 unrecovered media data 15 V vibration 27 29 W warranty 20 Z zero l...

Страница 79: ......

Страница 80: ...Seagate Technology LLC 920 Disc Drive Scotts Valley California 95066 4544 USA Publication Number 100453994 Rev B Printed in USA ...

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