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Fujitsu MHW2120BS, MHW2100BS, MHW2080BS, MHW2040BS manual Using the read segment buffer, Miss-hit

Models: MHW2040BS MHW2100BS MHW2060BS MHW2120BS MHW2080BS

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Operations

6.4.3 Using the read segment buffer

Methods of using the read segment buffer are explained for following situations.

6.4.3.1 Miss-hit

In this situations, the top block of read requested data is not stored at all in the data buffer. As a result, all of the read requested data is read from disk media.

1)HAP (host address pointer) and DAP (disk address pointer) are defined in the head of the segment allocated from Buffer. (If pre-read is executed, HAP is set at the requested data reading position.)

HAP (host address pointer)

Read segment

DAP (disk address pointer)

2)During reading of read requested data, the request data that has already been read is sent to the host system.

HAP

Read requested data is stored until this point

Read requested data			Free space

DAP

3)When reading of read requested data is completed and transfer of the read requested data to the host system is completed, reading of the disk continues until a certain amount of data is stored.

HAP (stop)

Read requested data	Read-ahead data

DAP

4)The following cache valid data is for the read command that is executed next:

Cache valid data

LAST LBA START LBA

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C141-E249

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Fujitsu MHW2120BS, MHW2100BS, MHW2080BS, MHW2040BS, MHW2060BS manual Using the read segment buffer, Miss-hit

Contents

Disk Drives Product Manual For Safe Operation Handling of This Manual Revision History This page is intentionally left blank Overview of Manual Conventions Conventions for Alert MessagesOperating Environment Liability Exception This page is intentionally left blank Important Alert Items Important Alert Messages This page is intentionally left blank Disk Drives Maintenance Manual Disk Drives Product Manual This page is intentionally left blank Contents Installation Conditions Theory of Device Operation Contents Interface 101 Operations IN-1 GL-1AB-1 Illustrations 171 Recommended connector specifications for the host Tables 106 Device Overview Adaptability FeaturesFunctions and performance Error correction and retry by ECC Low noise and vibrationHigh resistance against shock Connection to Sata interface Specifications 1/2 Device SpecificationsSpecifications summary Model and product number Examples of model names and product numbers Power Requirements Input VoltageRipple Slope of an input voltage at rise Power Requirements Current Requirements and Power Dissipation Current and power dissipation Environmental specifications Environmental SpecificationsCurrent fluctuation Typ. at +5 V when power is turned on Acoustic noise specification Shock and vibration specificationAcoustic Noise Shock and Vibration Service life Data assurance in the event of power failureMTBF= Mean time to repair Mttr Error Rate Unrecoverable read errorPositioning error Media Defects Advanced Power Management APM Recommended power-off sequence Advanced Power Management Device-initiated interface power management Dipm Interface Power Management IPMHost-initiated interface power management Hipm Interface power management Device Configuration Device Configuration System Configuration Sata interfaceDrive connection Read/write circuit This page is intentionally left blank Installation Conditions Dimensions Dimensions Frame MountingOrientation Limitation of mounting PCA Location of breather Ambient temperature Service area Handling cautions ESD Hios Device connector Connections with Host System Recommended connector specifications for the host system Connector specifications for host systemSignal segment and power supply segment Sata interface cable connection This page is intentionally left blank Theory of Device Operation Outline SubassembliesDisk Spindle Circuit Configuration Air filterServo circuit Spindle motor driver circuit Power supply configuration PCA Power-on Sequence Power-on operation sequence Self-calibration contents Self-calibration Command processing during self-calibration Execution timing of self-calibration Read/write Circuit Read/write preamplifier PreAMPWrite circuit Write precompensation Programmable filter circuit Read circuitAGC circuit Digital PLL circuit FIR circuitD converter circuit Viterbi detection circuit Servo Control Servo control circuit Power amplifier Microprocessor unit MPUServo burst capture circuit A converter DAC Data-surface servo format Physical sector servo configuration on disk surface Servo frame format Actuator motor control Operation to move the head to the reference cylinderSeek operation Track following operation Start mode Acceleration modeStable rotation mode Spindle motor control This page is intentionally left blank Interface Interface signals Physical Interface 5VDC/GND Comreset / CominitComwake Signal interface regulation Out of band signaling Align ContEOF Pmack RIP ROKRrdy SOF Electrical specifications FER Physical Layer Electrical Requirements 2/3 COMINIT/COMRESET Physical Layer Electrical Requirements 3/3 Connector pinouts Connector pinouts 5 P11 function Staggered Spin-upDriving Ready LED Requirements for P11 as an output pin Example of the circuit for driving Ready LED Hot Plug Conceptual diagram of communication layers Logical Interface Communication layers Physical layerLink layer Transport layer Outline of the Shadow Block Register Shadow Block Register Outline of the frame information structure FIS FIS types3.2 Register Host to Device FIS layout Register Device to Host DMA Active Device to Host DMA Setup Device to Host or Host to Device Bidirectional TAG Bist Active Bidirectional Bist combinations Data FIS Bidirectional layout PIO Setup Device to HostData Host to Device or Device to Host Bidirectional Block at the conclusion of all subsequent Data to Device Set Device Bits Device to Host 11 Set Device Bits FIS UNC Error FieldShadow block registers Features Field exp Sector Count Field expSector Number Field exp Cylinder Low Field exp Cylinder High Field exp Device/Head FieldHS3 HS2 HS1 HS0 HS3 Bit Device Write Fault DF bit Bit Error ERR bitStatus field Bit 7 Busy BSY bit Command Field Bit 2 Software Reset SrstDevice Control Field EStatus Field Command code and parameters 1/3 Host CommandsCommand code and parameters Command code and parameters 2/3 Command code and parameters 3/3 Command descriptions Error reporting conditions Recalibrate X’10’ to X’1F’ Read Sectors X’20’ or X’21’ LBA LBA LSB Write Sectors X’30’ or X’31’ 00 *1 Error information Write Verify X’3C’ Host Commands Read Verify Sectors X’40’ or X’41’ Host Commands Seek X’70’ to X’7F’ Execute Device Diagnostic X’90’ Diagnostic code Initialize Device Parameters X’91’ Download Microcode X’92’ Operation of Download Microcode Error reporting conditions Standby Immediate X’94’ or X’E0’ Interface Unload Feature Unload Immediate Command Standby X’96’ or X’E2’ Idle X’97’ or X’E3’ Interface Check Power Mode X’98’ or X’E5’ ’FF’ Comreset Sleep X’99’ or X’E6’ Smart X’B0’ 10 Features Field values subcommands and functions 1/3 10 Features Field values subcommands and functions 2/3 Smart Enable OperationsSmart Read LOG Smart Write LOG 10 Features Field values subcommands and functions 3/3 Smart Disable Operations’DB’ Smart ENABLE/DISABLE Auto OFF-LINE ’DA’ Smart Return Status Key C2h 1FF 12 Format of guarantee failure threshold value data11 Format of device attribute value data Data format version number Attribute ID Status Flag Current attribute valueAttribute value for the worst case so far Raw attribute value 14 Self-test execution status 13 Off-line data collection statusSelf-test execution status 16 Failure prediction capability flag 17 Drive error logging capability15 Off-line data collection capability Guarantee failure threshold Smart error loggingChecksum 18 Log Directory Data Format 19 Data format of Smart Summary Error Log 1/2 19 Data format of Smart Summary Error Log 2/2 Command data structureError data structure Total number of drive errors 20 Data format of Smart Comprehensive Error Log Smart Self-Test Self-test number Self-test index Current LBA under test 22 Selective self-test log data structureTest Span Feature Flags 23 Selective self-test feature flagsCurrent Span under test Selective Self-test pending time min Smart Command Transport SCT 24 SCT command and the function SCT Status Request SN = E0h, FR = D5h 25 Format of SCT Status Response 1/2 SET MAX EXT, DCO 25 Format of SCT Status Response 2/2 26 SCT Status code SCT Command SET SN = E0h, FR = D6 27 Action code 28 Write Same 1/2 29 Error Recovery Control 28 Write Same 2/2 30 Feature Control Command Feature Control Command 31 SCT Data Table 32 had Temperature SCT Read Data SN = E1h, FR = D5 SCT Write Data SN = E1h, FR = D6 Device Configuration XB1 Device Configuration RestoreDevice Configuration Freeze Device Configuration Identify Device Configuration Restore Features Field = C0h Device Configuration Freeze Lock Features Field = C1h Device Configuration Identify Features Field = C2h Device Configuration SET Features Field = C3h 33 Device Configuration Identify data structure 1/2 Word Value Content 33 Device Configuration Identify data structure 2/2 Read Multiple X’C4’ 12 Execution example of Read Multiple command Start sector No Write Multiple X’C5’ Start sector No SET Multiple Mode X’C6’ Interface Read DMA X’C8’ or X’C9’ MSB / LBA LSB / LBA Write DMA X’CA’ or X’CB’ Interface Read Buffer X’E4’ Flush Cache X’E7’ Write Buffer X’E8’ Identify Device X’EC’ Identify Device DMA X’EE’ 34 Information to be read by Identify Device command 1/3 ’3FFF’ 34 Information to be read by Identify Device command 2/3 34 Information to be read by Identify Device command 3/3 MHW2120BS MHW2100BS MHW2080BS MHW2060BS MHW2040BS ’3FFF’ Command without interrupt supports 2, 4, 8 and 16 sectors Host Commands Interface C141-E249 113 Interface C141-E249 115 Bit = Supports the Mode Word C141-E249 117 = SCT Error Recovery Control supported SET Features X’EF’ 35 Features field values and settable modes 1/2 35 Features field values and settable modes 2/2 See Table Data Transfer Mode Advanced Power Management APM Serial ATA Functions Automatic Acoustic Management AAM Write-Read-Verify feature optional36 Write-Read-Verify feature sector counts 37 Contents of Security SET Password data Error reporting conditions Security UNLOCKX’F2’ When the master password is selectedWhen the user password is selected Host Commands Security Erase Prepare X’F3’ Security Erase Unit X’F4’ Security Freeze Lock X’F5’ Error reporting conditions 39 Contents of security password Error reporting conditions Read Native MAX Address X’F8’ Lbalsb SET MAX X’F9’ SET MAX Address SET MAX SET Password Features Field = 01h Password information SET MAX Lock Features Field = 02h DH CH CL SN SC ER SET MAX Unlock Features Field = 03h SET MAX Freeze Lock Features Field = 04h SN EXP Read Sector S EXT X’24’ DescriptionCL EXP Read DMA EXT X’25’ Description Read Native MAX Address EXT X’27’ Read Multiple EXT X’29’ Read LOG EXT X2F CL EXP SN EXP 40 Data format of Read Log Ext log page 10h 41 Tag field information 42 Data format of Read Log Ext log page 11h 43 Counter Identifier information SCT Status Request SN = E0h SC EXP Error information 152 C141-E249 Write Sector S EXT X’34’ Description Write DMA EXT X’35’ Description SET MAX Address EXT X’37’ SET MAX LBA Write Multiple EXT X’39’ Write LOG EXT X3F Error information C141-E249 159 SCT Command SET SN = E0h SCT Write Data SN = E1h Read Verify Sector S EXT X’42’ Flush Cache EXT X’EA’ Write Multiple FUA EXT XCE Write DMA FUA EXT X3D Read FP DMA Queued Write FP DMA Queued Error posting 44 Command code and parameters 1/2Command Name Sfrw Sfrr 44 Command code and parameters 2/2 Command Protocol Non-data command protocolExecute Device Diagnostic Initialize Device Parameters Data Host PIO data-in command protocol PIO data-out command protocol 14 PIO data-in command protocol 15 PIO data-out command protocol DMA data-in command protocol Read DMA EXT Identfy Device Identfy Device DMA DMA data-out command protocol Write DMA EXT FUA EXT Native Command Queuing protocol Read FP DMA Queued Write FP DMA Queued 18 Read FP DMA Queued command protocol 19 Write FP DMA Queued command protocol Power-on and Comreset 20 Power-on sequence 21 Comreset sequence This page is intentionally left blank Operations Reset and Diagnosis Response to power-on Reset and Diagnosis Response to Comreset Response to Comreset Software settings preservation Comreset preservation requirements SET Address MAX EXT Response to a software reset Response to a software reset Power Save Power save modeActive mode Active idle mode Standby mode Sleep mode Power commands Partial mode Power Save Controlled by Interface Power Management IPMPower save mode of the interface Slumber mode Read-ahead Cache Data buffer structureExample of 8 MB buffer Read Multiple EXT Read DMA EXT Read FP DMA Queued Data that is a target of caching Commands that are targets of cachingCaching operation Invalidating caching-target data Using the read segment buffer Miss-hit Sequential hit Full hit Partial hit Command that are targets of caching Write CacheCache operation Invalidation of cached data Status report in the event of an error Comreset and software reset responseCashing function when power supply is turned on Enabling and disabling This page is intentionally left blank Bios standard for drives CommandConnector Connector Plug Host system side Actuator Power save mode Rotational delayHost receptacle Master Device Seek time Serial-ATASlave Device Status This page is intentionally left blank Bios AbrtAIC Amnf This page is intentionally left blank Index Index Example of model name and product Mode Read/write circuit block diagram Read Native MAX Address Smart summary error log, data Comment Form Japan This page is intentionally left blank C141-E249-01EN Page