ReadCommands | Maxtor 2B015H1, 2B010H1, 2B020H1 specification

INTERFACE COMMANDS

ReadCommands

Read Sector(s)

Reads from 1 to 256 sectors, as specified in the Command Block, beginning at the specified sector. (A sector count of 0 requests 256 sectors.) Immediately after the Command register is written, the drive sets the BSY bit and begins execution of the command. If the drive is not already on the desired track, an implied seek is performed.

Once at the desired track, the drive searches for the data address mark of the requested sector. The data address mark must be recognized within a specified number of bytes, or the Data Address Mark Not Found error will be reported. Assuming the data address mark is found:

1.The data field is read into the sector buffer.

2.Error bits are set (if an error was encountered).

3.The DRQ bit is set.

4.An interrupt is generated.

The DRQ bit is always set, regardless of the presence or absence of an error condition after the sector. Upon command completion, the Command Block registers contain the numbers of the cylinder, head and sector of the last sector read. Back-to-back sector read commands set DRQ and generate an interrupt when the sector buffer is filled at the completion of each sector. The drive is then ready for the data to be read by the host. DRQ is reset and BSY is set immediately when the host empties the sector buffer.

If an error occurs during Read Sector commands, the read terminates at the sector where the error occurred. The host may then read the Command Block to determine the nature of that error, and the sector where it happened. If the error type is a correctable or an non-correctable data error, the flawed data is loaded into the sector buffer.

A Read Long command sets the Long bit in the command code and returns the data and the ECC bytes in the data field of the specified sector. During a Read Long, the drive does not check the ECC bytes to determine if there has been a data error. The Read Long command is limited to single sector requests.

Read Verify Sector(s)

Identical to the Read Sector(s) command, except that:

1.DRQ is never set,

2.No data is transferred back to the host and

3.The long bit is not valid.

7 – 2

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Maxtor 2B015H1, 2B010H1, 2B020H1 manual ReadCommands

Contents

Maxtor 541DX Product Manual Before You Begin U T I O N Contents Product Specifications Handling and Installation Interface Commands AT Interface DescriptionHost Software Interface Service and Support Glossary Figures ManualOrganization IntroductionMaxtorCorporation Abbreviations Conventions Key Features ProductDescription Product Features Functional / InterfaceModels CYL SP T MAX LBA Capacity CacheManagement Major HDA Components Jumper Configuration SubsystemConfigurationJumper Location / Configuration Cylinder Limitation Jumper Description PerformanceSpecifications ProductSpecificationsDrive Configuration Models and Capacities Physical Dimensions Param Eter Valu E EPA Energy Star Compliance PowerRequirementsPower Mode Definitions Environmental Limits Reliability Specifications Shock and VibrationParam Eter Oper AT ING ON- Oper AT ING Safety Regulatory Compliance EMC/EMI HandlingandInstallation Hard Drive Handling PrecautionsElectro-Static Discharge ESD Unpacking and Inspection Multi-pack Shipping Container Physical Installation Repacking Before You Begin Hook up Set up Start up PinDescriptionSummary InterfaceConnectorATInterfaceDescription PIN IGN AL PIN Name Signal Name Signal Desc Ription Pin Description Table IM in G Paramet ERS Mode PIO Timing Imin G Paramet ERS Mode DMATiming Ultra DMA Timing Mode Sustained Ultra DMA Data In Burst Device Terminating an Ultra DMA Data In Burst Initiating an Ultra DMA Data Out Burst Device Pausing an Ultra DMA Data Out Burst Device Terminating an Ultra DMA Data Out Burst HostSoftwareInterface Task File RegistersPOR T EAD WR ITE Conten TS LBA Bits CommandRegister Seek, Format, and Diagnostic Commands Summary M M a N D N a M E M M a N D code PA R a M E T E R S U S E D Control Diagnostic Registers Reset and Interrupt Handling InterfaceCommands ReadCommands Read DMA WriteCommands Write Multiple ModeSet/CheckCommands VAL UE DES C RIP TionEC TOR LE VE L VAL UE Omman D PowerModeCommands Timer VAL UE TIME-OUT Period Sleep Mode InitializationCommands Or D ENT Desc Ription Or D 15- 10, as c urrently defined Initialize Drive Parameters Seek,FormatandDiagnosticCommands ER ROR Code Desc Ription A.R.T. CommandSet Key Register No Quibble Service ServiceandSupportService Policy Product Support From Dial Glossary Channel Correctable errorCentral processing unit CPU Character Error correction code ECC Direct accessDirect memory access DMA Error free Frequency response Hard errorHead disk assembly HDA Gigabyte GB Logic Late windowLatency Logical address Random access memory RAM Phase locked loop PLLPhase margin Read gate signal Sequential access Sector pulse signalSeek complete signal Soft error Unrecoverable error Strobe offset signalUn-correctable error Write gate signal