Maxtor Comprehensive Guide to Microscope and Magnifier Functionality and Interfaces
Page 36

HOST SOFTWARE INTERFACE

Sector Count Register

Holds the number of sectors to be sent during a Read or Write command, and the number of sectors per track during a Format command. A value of zero in this register implies a transfer of 256 sectors. A multi- sector operation decrements the Sector Count register. If an error occurs during such an operation, this register contains the remaining number of sectors to be transferred.

Sector Number Register

Holds the starting sector number for any disk operation. The register is updated as each sector is processed in a multi-sector operation.

Cylinder Number Registers

Two 8-bit Cylinder Number registers (Low and High) specify the starting cylinder for disk operation.

Device/Head Register

Used to specify the drive and head number to be operated on during any disk operations. Within the context of a Set Parameters command, this register specifies the maximum number of heads on the drive. Bit definitions follow:

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

1

LBA

1

DRV

HS3

HS2

HS1

HS0

 

 

 

 

 

 

 

 

 

LBA

 

Dr ive

Head

Head

Head

Head

 

Mode

 

Select

Select

Select

Select

Select

 

 

 

 

 

 

 

 

Select LBA Mode – Enabling this bit for commands not supported by LBA mode will abort the selected command. When set, the Task File register contents are defined as follows for the Read/Write and translate command:

CONTEN TS

LBA BITS

 

 

 

Sector Number

0

- 7

 

 

Cylinder Low

8 - 15

C ylinder High

16

- 23

 

 

 

D rive/Head

24

- 27

 

 

 

Drive Select – Set to 0 to select the master drive; set to 1 to select the slave drive.

Head Select – Specifies the binary coded address of the head to be selected.

Status Register

Contains results of the last command executed, and the drive’s status. The other seven Task File registers may be read only when bit 7 (BUSY) of the Status register is low. Reading any of the Task File registers when BUSY is high returns the value of the Status register. Reading the Status register also clears any interrupt request to the host. Bit definitions follow:

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

BUSY

D RDY

D F

D SC

D RQ

0

0

ERR

 

 

 

 

 

 

 

 

C ontroller

Device

Device

Device

D ata

 

 

Error

Busy

Ready

Fault

Seek

Request

 

 

 

 

 

 

C omplete

 

 

 

 

Controller Busy – Goes active when a command is written to the Command register, indicating controller task execution. After a command, this bit resets.

Device Ready – Indicates that the drive is ready for commands. If drive ready is not present, all commands abort. Device Fault – Indicates the drive’s detection of a write fault condition, causing all commands to abort. Device Seek Complete – Signifies a seek completion, and that the drive is on track.

Data Request – Indicates that the drive’s sector buffer is ready for data transfer.

Error – The Error bit sets when the previous command has completed with a non-recoverable error.

6 – 2

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Contents Maxtor 541DX Product Manual Before You Begin U T I O NContents Product Specifications Handling and InstallationInterface Commands AT Interface DescriptionHost Software Interface Service and Support GlossaryFigures Introduction MaxtorCorporationManualOrganization AbbreviationsConventions Key Features ProductDescriptionProduct Features Functional / InterfaceModels CYL SP T MAX LBA Capacity CacheManagement Major HDA Components SubsystemConfiguration Jumper Location / ConfigurationJumper Configuration Cylinder Limitation Jumper DescriptionProductSpecifications Drive ConfigurationPerformanceSpecifications Models and CapacitiesPhysical Dimensions Param Eter Valu EPowerRequirements Power Mode DefinitionsEPA Energy Star Compliance Environmental LimitsReliability Specifications Shock and VibrationParam Eter Oper AT ING ON- Oper AT ING Safety Regulatory Compliance EMC/EMIHandlingandInstallation Hard Drive Handling PrecautionsElectro-Static Discharge ESD Unpacking and Inspection Multi-pack Shipping ContainerPhysical Installation RepackingBefore You Begin Hook upSet up Start upInterfaceConnector ATInterfaceDescriptionPinDescriptionSummary PIN IGN ALPIN Name Signal Name Signal Desc Ription Pin Description TableIM in G Paramet ERS Mode PIO TimingImin G Paramet ERS Mode DMATimingUltra DMA Timing ModeSustained 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 CommandsSummary 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 DControl 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 PeriodSleep Mode InitializationCommands Or D ENT Desc RiptionOr D 15- 10, as c urrently defined Initialize Drive Parameters Seek,FormatandDiagnosticCommands ER ROR Code Desc RiptionA.R.T. CommandSet Key RegisterServiceandSupport Service PolicyNo Quibble Service Product SupportFrom Dial Glossary Correctable error Central processing unit CPUChannel CharacterDirect access Direct memory access DMAError correction code ECC Error freeHard error Head disk assembly HDAFrequency response Gigabyte GBLate window LatencyLogic Logical addressPhase locked loop PLL Phase marginRandom access memory RAM Read gate signalSector pulse signal Seek complete signalSequential access Soft errorStrobe offset signal Un-correctable errorUnrecoverable error Write gate signal
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