Seagate ST3120026AS, ST3120827AS, ST3120022AS, ST310005N1A1ASRK Set Features command values

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4.3.2Set Features command

This command controls the implementation of various features that the drive supports. When the drive receives this command, it sets BSY, checks the contents of the Features register, clears BSY and generates an inter- rupt. If the value in the register does not represent a feature that the drive supports, the command is aborted. Power-on default has the read look-ahead and write caching features enabled. The acceptable values for the Features register are defined as follows:

Table 9: Set Features command values

02H	Enable write cache (default).
03H	Set transfer mode (based on value in Sector Count register).
	Sector Count register values:
	00H	Set PIO mode to default (PIO mode 2).
	01H	Set PIO mode to default and disable IORDY (PIO mode 2).
	08H	PIO mode 0
	09H	PIO mode 1
	0AH	PIO mode 2
	0BH	PIO mode 3
	0CH	PIO mode 4 (default)
	20H	Multiword DMA mode 0
	21H	Multiword DMA mode 1
	22H	Multiword DMA mode 2
	40H	Ultra DMA mode 0
	41H	Ultra DMA mode 1
	42H	Ultra DMA mode 2
	43H	Ultra DMA mode 3
	44H	Ultra DMA mode 4
	45H	Ultra DMA mode 5
55H	Disable read look-ahead (read cache) feature.
82H	Disable write cache
AAH	Enable read look-ahead (read cache) feature (default).
F1H	Report full capacity available

Note. At power-on, or after a hardware or software reset, the default values of the features are as indi- cated above.

32	Barracuda 7200.7 Serial ATA Product Manual, Rev. N

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Contents Barracuda 7200.7 Serial ATA Page Barracuda 7200.7 Serial ATA Page Contents Barracuda 7200.7 Serial ATA Product Manual, Rev. N List of Figures Page Introduction Native Command Queuing About the Serial ATA interfaceDrive specifications Specification summary tableSystem will display the warranty information for your drive Default logical geometry LBA modeFormatted capacity Cylinders Read/write heads Sectors per track 16,383Physical characteristics Drive specificationPhysical organization Recording and interface technologySeek time Power specificationsStart/stop times Idle mode power Operating power and currentStandby mode Typical current profiles Deferred spinupConducted noise Additional detailsVoltage tolerance Environmental specifications Temperature gradient Wet bulb temperatureHumidity Relative humidity AltitudeAcoustics VibrationOperating vibration Nonoperating vibrationElectromagnetic immunity ReliabilityRadio frequency environments Test Description Performance level Reference standardSafety certification Agency certificationElectromagnetic compatibility Korean RRLAustralian C-Tick N176 FCC verificationCorrosive environment Environmental protectionEuropean Union Restriction of Hazardous Substances RoHS Barracuda 7200.7 Serial ATA Product Manual, Rev. N Configuring and mounting the drive Handling and static-discharge precautionsConfiguring the drive Serial ATA cables and connectorsDrive mounting Mounting dimensions-top, side and end view Serial ATA Sata interface Hot-Plug compatibilitySerial ATA device plug connector pin definitions Serial ATA connector pin definitionsSignal Pin Function DefinitionPage Supported ATA commands Command name Command code in hex ATA-standard commandsATA-standard power-management commands Command name Command code in hexATA-standard security commands Identify Device command Word Description ValueXxxxH Fffeh Description if bit is set to Bit Word Bit WordSet Features command Set Features command valuesM.A.R.T. commands 3 S.M.A.R.T. commandsCode in features register A.R.T. command Barracuda 7200.7 Serial ATA Product Manual, Rev. N Presales Support Internet MySeagate Reseller.seagate.comTechnical Support Data Recovery Services Authorized Service Centers Warranty ServiceData Recovery Services Call center Presales and Technical Support Warranty Service FAX services-All Europe toll callToll-free support numbers Asia/Pacific support services Publication feedback survey Barracuda 7200.7 Serial ATA Product Manual, Rev. N Index Mtbf RPM RRL Page Page Seagate Technology LLC