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Fujitsu MHU2100AT manual Partial hit

Models: MHU2100AT

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Operations

6.4.3.4 Partial hit

In this situation, a part of read requested data including the top sector is stored in the data buffer. A transfer of the read requested data starts from the address where the data that is hit is stored until the top sector of the read requested data. Remaining part of insufficient data is read then.

An example is a case where a partial hit occurs in cache data, as shown below.

Cache valid data

TART LBA			LAST LBA

1)HAP is set at the address where partial hit data is stored, and Transfer is started.

HAP (host address pointer)

Cache valid data

Partial hit data

2)DAP and HAP are set at the head of Buffer newly allocated, and insufficient data is read.

HAP (host address pointer)

Read segment

DAP (disk address pointer)

3)When reading the read requested data ends and the transmission of the read requested data to the host system ends, the read-ahead operation continues until a certain amount of data is stored.

The method of storing the read-ahead data at Partial hit is the same as the Miss hit.

Cache valid data

LAST LBA START LBA

6-18	C141-E202-01EN

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Fujitsu MHU2100AT manual Partial hit

Contents

MHU2100AT Disk Drive Product Manual For Safe Operation Handling of This ManualRevision History This page is intentionally left blank Preface Overview of ManualOperating Environment Conventions for Alert MessagesConventions Liability Exception This page is intentionally left blank Important Alert Items Important Alert MessagesThis page is intentionally left blank Manual Organization MHU2100AT Disk Drive Maintenance ManualMHU2100AT Disk Drive Product Manual This page is intentionally left blank Contents Installation Conditions Theory of Device OperationContents Interface100 120 Operations Glossary GL-1 Acronyms and Abbreviations AB-1 Index IN-1 Illustrations FiguresExecution example of Read Multiple command Surface temperature measurement points and standard Tables25 Relationship between combination of Identifier This page is intentionally left blank Device Overview Functions and performance FeaturesAdaptability Error correction and retry by ECC Connection to ATA interfaceData buffer Read-ahead cache systemSpecifications summary Device SpecificationsSpecifications 1 Specifications 2 Model and product numberMHU2100AT Examples of model names and product numbersInput Voltage Power RequirementsRipple Current and power dissipation Environmental Specifications Current fluctuation Typ. at +5 V when power is turned onPower on/off sequence Environmental specificationsAcoustic noise specification Shock and vibration specificationAcoustic Noise Shock and VibrationService life Data assurance in the event of power failureReliability Mean time between failures MtbfError Rate Unrecoverable read errorPositioning error Media DefectsAdvanced Power Management Advanced Power Management Advanced Power ManagementThis page is intentionally left blank Device Configuration Device Configuration System Configuration ATA interface2 1 drive connection Read/write circuit2 drives configuration 3 2 drives connectionInstallation Conditions Dimensions DimensionsIntegration Guidance C141-E144 MountingOrientation Limitation of mounting FramePCA Location of breather Ambient temperature Service area Handling cautionsHandling cautions Device connector Cable ConnectionsCable connector specifications Cable connector specificationsDevice connection FCIPower supply connector CN1 Jumper SettingsLocation of setting jumpers Factory default setting Master drive-slave drive settingCsel setting 14 Csel settingPower Up in Standby setting 16 Example 2 of Cable SelectTheory of Device Operation Outline SubassembliesDisk SpindleCircuit Configuration Air filterServo circuit Spindle motor driver circuitPower Supply Configuration PCA Power-on Sequence Power-on operation sequenceSelf-calibration contents Self-calibrationCommand processing during self-calibration Execution timing of self-calibrationRead/write Circuit Read/write preamplifier PreAMPWrite circuit RLL code MeeprmlAGC circuit Read circuitProgrammable filter circuit Digital PLL circuit FIR circuitD converter circuit Viterbi detection circuitServo Control Servo control circuitPower amplifier Microprocessor unit MPUServo burst capture circuit A converter DACDriver circuit Spindle motor control circuitVCM current sense resistor CSR Data-surface servo format Inner guard bandData area Outer guard bandPhysical sector servo configuration on disk surface Servo frame format Actuator motor control Operation to move the head to the reference cylinderSeek operation Track following operationStart mode Acceleration modeStable rotation mode Spindle motor controlTheory of Device Operation Interface Interface signals Physical InterfaceSignal assignment on the connector Signal assignment on the interface connectorDA1 PDIAG-, Cblid DA0 DA2 Dasp GNDMstr DiowStop DiorPdiag CblidDasp IordyLogical Interface I/O registers 1 I/O registersDA2 DA1 DA0 Command block registers Error register X’1F1’Data register X’1F0’ UNC IdnfSET Multiple Mode Features register X’1F1’Sector Count register X’1F2’ Cylinder Low register X’1F4’ Sector Number register X’1F3’Cylinder High register X’1F5’ Device/Head register X’1F6’ DEV HS3 HS2 HS1 HS0Status register X’1F7’ BSYInterface Control block registers Command register X’1F7’Alternate Status register X’3F6’ Host Commands Command code and parametersDevice Control register X’3F6’ HOB SrstCommand Name Command code and parameters 1Parameter Used Command code and parameters 2 EXT Flush Cache EXTHost Commands Command descriptions Host Commands Recalibrate X’10’ to X’1F’ Read Sectors X’20’ or X’21’ MSBEnd head No. / LBA MSB Read Long X’22’ or X’23’ Write Sectors X’30’ or X’31’ 1F7 HST Status information 1F6 HDH Write Long X’32’ or X’33’ Write Verify X’3C’ Read Verify Sectors X’40’ or X’41’ Seek X’70’ to X’7F’ Execute Device Diagnostic X’90’ Diagnostic codeHost Commands Initialize Device Parameters X’91’ Download Micro Code X’92’ Operation of Download Micro Code Standby Immediate X’94’ or X’E0’ Idle Immediate X’95’ or X’E1’ Standby X’96’ or X’E2’ Idle X’97’ or X’E3’ Host Commands Check Power Mode X’98’ or X’E5’ ’FF’Sleep X’99’ or X’E6’ Smart X’B0 Features Register values subcommands and functions 1 Features Register values subcommands and functions 2 Smart Enable OperationsSmart Disable Operations Smart Read LOGSmart ENABLE/DISABLE Auto OFF-LINE Features Register values subcommands and functions 3’DA’ Smart Return Status Interface 1FF Format of device attribute value dataFormat of insurance failure threshold value data Data format version number Attribute IDStatus Flag Current attribute valueAttribute value for the worst case so far Raw attribute valueSelf-test execution status 10 Off-line data collection status11 Self-test execution status Off-line data collection capability 12 Off-line data collection capabilityFailure prediction capability flag 13 Failure prediction capability flagError logging capability 14 Error logging capabilityCheck sum Insurance failure thresholdSmart error logging 16 Data format of Smart Summary Error Log Command data structure Error data structureTotal number of drive errors 17 Data format of Smart Comprehensive Error LogSmart Self-Test 18 Smart self-test log data format1FC Self-test number19 Selective self-test log data structure Test SpanCurrent LBA under test Current Span under test20 Selective self-test feature flags Feature FlagsSelective Self-test pending time min Device Configuration XB1 Device Configuration RestoreDevice Configuration Freeze Device Configuration IdentifyDevice Configuration Restore FR = C0h Device Configuration Freeze Lock FR = C1hDevice Configuration Identify FR = C2h Device Configuration SET FR = C3hHost Commands 21 Device Configuration Identify data structure Execution example of Read Multiple command Read Multiple X’C4’MSB Write Multiple X’C5’ Interface SET Multiple Mode X’C6’ Interface Read DMA X’C8’ or X’C9’ End head No. / LBA MSB 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’ 22 Information to be read by Identify Device command 1 ’3FFF’22 Information to be read by Identify Device command 2 Word Command without interrupt supports 2, 4, 8 and 16 sectors = Supports the Host Protected Area feature set = Supports the CFA Compact Flash Association feature set Interface Host Commands Diagnosis Word Bit Reserved Security level High, 1 Maximum SET Features X’EF’ 23 Features register values and settable modes’AA’ ’BB’Data Transfer Mode Advanced Power Management APM Automatic Acoustic Management AAM 24 Contents of Security SET Password data At command issuance I-O register contents 1F7 hCM 1F6 hDH When the user password is selected When the master password is selectedSecurity UNLOCKX’F2’ Host Commands Security Erase Prepare X’F3’ Security Erase Unit X’F4’ Security Freeze Lock X’F5’ At command issuance I-O register contents 1F7 hCM 1F6 hDH 26 Contents of security password Host Commands Read Native MAX Address X’F8’ SET MAX X’F9’ SET MAX AddressSET MAX SET Password FR = 01h SET MAX Lock FR = 02h SET MAX Unlock FR = 03h SET MAX Freeze Lock FR = 04h Interface Read Sectors EXT X’24’ Option customizing Description Read DMA EXT X’25’ Option customizing Description HOB=0 Error reporting conditionsHOB=1 Read Multiple EXT X’29’ Option customizing Description Read LOG EXT X2F Optional command Customize Description Interface Write Sectors EXT X’34’ Option customizing Description Write DMA EXT X’35’ Option customizing Description SET MAX Address EXT X’37’ Option customizing Description SET MAX LBA Write Multiple EXT X’39’ Option customizing Description Write LOG EXT X’3F’ Optional command Customize Description Host Commands Read Verify Sectors EXT X’42 Option customizing Description Flush Cache EXT X’EA’ Option customizing Description Error posting 27 Command code and parameters 127 Command code and parameters 2 PIO Data transferring commands from device to host Command ProtocolExecute Device Diagnostic Initialize Device Parameters Read Sectors Command protocol Protocol for command abort PIO Data transferring commands from host to device Write Sectors command protocol Commands without data transfer Other commands DMA data transfer commandsRead Multiple EXT Write Multiple EXT Sleep Read DMA EXT Write DMA EXT Indentify Device DMANormal DMA data transfer Ultra DMA Feature Set OverviewUltra DMA data in commands Phases of operationInitiating an Ultra DMA data in burst Pausing an Ultra DMA data in burst Data in transferTerminating an Ultra DMA data in burst Interface Ultra DMA Feature Set Ultra DMA data out commands Initiating an Ultra DMA data out burstPausing an Ultra DMA data out burst Data out transferTerminating an Ultra DMA data out burst Ultra DMA Feature Set Ultra DMA CRC rules Series termination required for Ultra DMA 28 Recommended series termination for Ultra DMADIOR-HDMARDY-HSTROBE DIOW-STOPPIO data transfer TimingPIO data transfer timing 10 Multiword DMA data transfer timing mode Multiword data transferUltra DMA data transfer 11 Initiating an Ultra DMA data in burstName Mode Comment Strobe29 Ultra DMA data burst timing requirements 2 MIN MAXMode Name Comment 30 Ultra DMA sender and recipient timing requirementsSustained Ultra DMA data in burst Dstrobe at deviceDD150 at device Dstrobe at host DD150 at hostHost pausing an Ultra DMA data in burst DmarqDmack StopDevice terminating an Ultra DMA data in burst Host Host terminating an Ultra DMA data in burstDA0, DA1, DA2 CS0, CS1 16 Initiating an Ultra DMA data out burst Hstrobe at host DD150 at host Sustained Ultra DMA data out burstHstrobe at device DD150 at device Device DMACK- host Stop host DDMARDY- device Device pausing an Ultra DMA data out burstHstrobe host DD150 Host Host terminating an Ultra DMA data out burst 19 Host terminating an Ultra DMA data out burstDmarq device DMACK- host Device terminating an Ultra DMA data out burstDD150 Host Master and slave devices are present 2-drives configuration Power-on and resetOnly master device is present This page is intentionally left blank Operations Device Response to the Reset Response to power-onResponse to hardware reset Response to power-onResponse to hardware reset Response to software reset Response to software resetResponse to diagnostic command Response to diagnostic commandPower Save Power save modeActive mode Active idle modeStandby mode Sleep modeDefect Processing Power commandsSpare area Sector slip processing Alternating processing for defective sectorsTrack slip processing Automatic alternating processing Automatic alternating processingRead-ahead Cache Data buffer structure8MB buffer 8,388,608 bytes Read Sectors EXT Read Multiple EXT Read DMA EXTCommands that are targets of caching Caching operationRead Multiple EXT Read Dmaext Data that is a target of cachingOperations Using the read segment buffer Miss-hitSequential Hit Full hit Partial hit Command that are targets of caching Write CacheCache operation Invalidation of cached dataStatus report in the event of an error Reset responseCashing function when power supply is turned on Enabling and disablingWrite Cache This page is intentionally left blank Glossary Power save mode Rotational delayPIO Programmed input-output PositioningStatus VCMThis page is intentionally left blank Acronyms and Abbreviations This page is intentionally left blank Index AAMIndex Information to be read by Identify Read Sectors Command Read Native MAX AddressSurface temperature measurement This page is intentionally left blank Comment Form JapanThis page is intentionally left blank C141-E202-01EN This page is intentionally left blank