Samsung 3.5" hard disk drives manual Read Buffer E4h, Read Long 22hwith retry, 23h without retry

Page 71

DISK DRIVE OPERATION

The sector count and head values are not checked for validity by this command. If they are invalid, no error will be posted until an illegal access is made by some other command.

6.4.10 Read Buffer (E4h)

The Read Buffer command enables the host to read the current contents of the drive's sector buffer. When this command is issued, the drive sets BSY, sets up the sector buffer for a read operation, sets DRQ, clears BSY, and generates an interrupt. The host then reads up to 512 bytes of data from the buffer.

The Read Buffer and Write Buffer commands are synchronized so that sequential Write Buffer (E8h) and Read Buffer commands access the same 512 bytes within the buffer.

6.4.11Read DMA (C8h:with retry, C9h:without retry)

This command executes in a manner similar to the Read Sector(s) command except for the following:

•The host initializes a slave-DMA channel prior to issuing the command

•Data transfers are qualified by DMARQ and are performed by the slave-DMA channel

•The drive issues only one interrupt per command to indicate that data transfer has stopped and the status is available.

Any unrecoverable error encountered during execution of a Read DMA command results in the termination of data transfer prior to the sector where the error was detected. The drive generates an interrupt to indicate that data transfer has terminated and status is available. The error posting is the same as that for the Read Sector(s) command.

6.4.12Read Long (22h:with retry, 23h: without retry)

The Read Long command performs similarly to the Read Sectors command except that it returns the data and the ECC bytes appended to the data field of the desired sector. During a Read Long command, the drive does not check the ECC bytes to determine if there has been a data error. Only single sector Read Long operations are supported.

The transfer of the ECC bytes shall be 8 bits wide, and 4 or device native ECC bytes length.

SpinPoint V40 Product Manual

63

Image 71

Contents Spinpoint SpinPoint V40 Product Manual Table of Contents Smart Ervo S Ystem EAD and W Rite O PerationsIrmware F Eatures Timing Programming RequirementsProtocol Overview General Information Maintenance PrecautionsService and Repair 107Table of Figures Page Scope User DefinitionManual Organization Format C/S Commands and MessagesTerminology and Conventions Computer MessageReference Description Key FeaturesIntroduction Hardware Requirements Standards and RegulationsSpecifications Specification SummaryLogical Configurations Physical SpecificationsPerformance Specifications 28.71 Power RequirementsSV6003H SV6014H SV8004H Environmental SpecificationsMtbf POH Reliability SpecificationsSpace Requirements InstallationOrientation Unpacking InstructionsMounting 2Mounting Dimensions in Millimeters 3Mounting-Screw Clearance ClearanceVentilation Cable ConnectorsDC Power Connector AT-Bus Interface ConnectorSpinPoint V40 Product Manual Jumper Block Configurations Options for Jumper Block Configuration 7DC Power Connector and AT-Bus Interface Cable Connections Drive InstallationParameter System Startup ProcedureSystem Setup Disk Drive Operation Head / Disk Assembly HDABase Casting Assembly DC Spindle Motor AssemblyExploded Mechanical View Air Filtration System Disk Stack AssemblyHead Stack Assembly Voice Coil Motor and Actuator Latch AssembliesAT Disk Controller Digital Signal Process and Interface ControllerDrive Electronics 2SID2001 AT Controller Block Diagram Host Interface Control Block Disk Control Block Buffer Control BlockSpinPoint V40 Product Manual Frequency Synthesizer Power ManagementRead/Write IC Disk ECC Control BlockAnalog Anti-Aliasing Low Pass Filter Time Base GeneratorAutomatic Gain Control Asymmetry Correction Circuitry ASC3Read/Write 88C5200 Read Channel Servo SystemRead and Write Operations Read Caching Firmware FeaturesWrite Channel Write Caching Smart Defect ManagementAutomatic Defect Allocation Multi-burst ECC CorrectionBlank Physical Interface Signal ConventionsSignal Summary Signal Descriptions IOCS16- Drive 16-bit I/O DMACK- DMA AcknowledgeDmarq DMA Request Intrq Drive InterruptIordy I/O Channel Ready PDIAG- Passed DiagnosticsRESET- Drive Reset SD2 SD8 SD6 SD9 SD5SD4 SD3Drive Host DriveDIR Environment Logical InterfaceGeneral Bit ConventionsSpinPoint V40 Product Manual N N N A a a Command Block Registers2 I/O Register Address Control Block RegistersDevice Control Register 3F6h Control Block Register DescriptionsAlternate Status Register 3F6h Drive Address Register 3F7hData Register 1F0h Command Block Register DescriptionsFeatures Register 1F1h Error Register 1F1hCylinder Low Register 1F4h Command Register 1F7hSector Count Register 1F2h Cylinder High Register 1F5hBSY Drdy DWF DSC DRQ Corr IDX ERR Status Register 1F7hAt Command Register Descriptions Command Parameter Used SpinPoint V40 Product Manual Download Micro Code 92h Check Power Mode 98h, E5hExecute Device Diagnostics 90h Identify Device ECh Flush Cache E7hFormat Track 50h Xxxx Word Content DescriptionCapabilities Command set supported 95-128 0000h Reserved 129-159 Vendor specific 160-255 Initialize Device Parameters 91h Idle 97h,E3hIdle Immediate 95h,E1h Read Long 22hwith retry, 23h without retry Read Buffer E4hRead Multiple Command C4h Read Sectors 20hwith retry, 21hwithout retry Read Native Max Address F8hSeek 7xh Read Verify Sectors 40hwith retry, 41hwithout retryRecalibrate 1xh Mode Set Features EFhBSY Drdy DRQ ERR InputsLBA Normal outputsDescription Sleep 99h, E6h Set Multiple Mode C6hSmart B0h Smart disable operation D9hStandby 96h,E2h Smart execute off-line immediate D4h Smart enable/disable attribute autosave D2hSmart enable operations D8h Byte Descriptions Smart read data D0hOff-line data collection capability Value DefinitionSmart save attribution value D3h Smart capabilitySmart read log sector D5h Smart return status DAhWrite DMA CAh Standby 96h, E2hStandby Immediate 94h, E0h Write Buffer E8hWrite Sectors 30hwith retry, 31hwithout retry Write Multiple Command C5hSpinPoint V40 Product Manual Programming Requirements Reset ResponseError Posting BBK Command Error Register Status RegisterIdle mode Power ConditionsSleep mode Standby modeNormal mode Protocol Overview PIO Data in CommandsPIO Read Aborted Command PIO Data Out CommandsPIO Read Command BSY=0 DRQ=1 BSY=1 DRQ=0 PIO Write CommandPIO Write Aborted Command BSY=0 DRDY=1 BSY=1Non-Data Commands DMA Data Transfer Commands BSY=1 BSY=0 Aborted DMA Command Initialize DMA Reset DMA StatusBSY=0 BSY=1 Register transfers TimingDIOR-/DIOW Write PIO data transfers PIO timing parameters ModeAddr valid See note T1 t2 DIOR-/DIOW DIOR-/DIOW Multiword DMA data transferMultiword DMA timing parameters Mode Initiating an Ultra DMA data in burst Ultra DMA data transfer19Ultra DMA data burst timing requirements Ultra DMA data burst timing requirements5Sustained Ultra DMA data in burst Sustained Ultra DMA data in burst6Host pausing an Ultra DMA data in burst Host pausing an Ultra DMA data in burst7Device terminating an Ultra DMA data in burst 100 Device terminating an Ultra DMA data in burst8Host terminating an Ultra DMA data in burst Host terminating an Ultra DMA data in burst9Initiating an Ultra DMA data out burst 102 Initiating an Ultra DMA data out burst10Sustained Ultra DMA data out burst Sustained Ultra DMA data out burst11Device pausing an Ultra DMA data out burst 104 Device pausing an Ultra DMA data out burst12Host terminating an Ultra DMA data out burst Host terminating an Ultra DMA data out burst13Device terminating an Ultra DMA data out burst 106 Device terminating an Ultra DMA data out burstGeneral Information Maintenance PrecautionsService And Repair