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Seagate ST920814AM, ST940813AM, ST940814AM, ST930814AM Set Features command, Disable write cache

Models: ST940813AM ST920814AM ST920813AM ST940814AM ST930813AM ST930814AM

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4.1.3Set 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:

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

05H	Enable advanced power management

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 indicated above.

EE25 Series Product Manual, Rev. E

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Seagate ST920814AM, ST940813AM, ST940814AM, ST930814AM, ST930813AM, ST920813AM manual Set Features command, Disable write cache

Contents

Product Manual ST940813AM ST940814AM ST930813AM ST930814AM ST920813AM ST920814AMEE25 Series August 5.0 Seagate Technology support services Contents1.0 Introduction 2.0 Drive specifications 3.0 Configuring and mounting the driveEE25 Series Product Manual, Rev. E List of Figures EE25 Series Product Manual, Rev. E 1.0 Introduction EE25 Series Product Manual, Rev. E 2.1 Specification summary 2.0 Drive specificationsEE25 Series Product Manual, Rev. E Specifications for 40 and 30 Gbyte modelsfollowing web page EE25 Series Product Manual, Rev. E1.0 G 200 - 500 Hz 5.0 Gs 0 to peak, 5-500 Hz X, Y, Z axis 0, 22, 45 angles5% to 90% operating Specifications for 20 Gbyte modelsST920814AM Drive specificationEE25 Series Product Manual, Rev. E ST920813AMLBA mode 2.3 Default logical geometry2.2 Formatted capacity 2.4 Physical organizationSpecification 2.6 Physical characteristics2.5 Recording and interface technology 2.7 Seek timeEE25 Series Product Manual, Rev. E Start/stop timesRead/write power and current 2.9 Power specifications2.9.1 Power consumption Spinup powerFigure 1. Typical 5V startup and operation current profile 2.9.1.1 Typical current profile2.9.2 Conducted noise 2.9.3 Voltage toleranceIdle mode 2.9.4 Power-management modesIdle and Standby timers Active mode2.10.2 Temperature gradient 2.10 Environmental specifications2.11 Altitude 2.10.1 Ambient temperatureFigure 2. Temperature vs. altitude capability 2.11.1 Shock2.11.1.1 Operating shock 2.11.1.2 Nonoperating shock2.11.2.2 Nonoperating vibration 2.12 Acoustics2.11.2 Vibration 2.11.2.1 Operating vibrationReliability 2.13 Electromagnetic immunity2.14 Korean RRL 2.15.1 Safety certification2.15 Agency certification 2.15.2 Electromagnetic compatibility2.16.1 European Union Restriction of Hazardous Substances RoHS 2.16 Environmental protection2.17 Corrosive environment EE25 Series Product Manual, Rev. E 3.2.1 Master/slave configuration 3.0 Configuring and mounting the drive3.1 Handling and static discharge precautions 3.2 Jumper settings3.2.2 Cable-select option 3.3 Drive mounting4.0 ATA interface 4.1 ATA interface signals and connector pinsATA-standard commands 4.1.1 Supported ATA commandsCommand name Command code in hex9AH, FAH, FBH EE25 Series Product Manual, Rev. E4.1.2 Identify Device command xx3FH xxxxHxxxxH xx07HxxxxH EE25 Series Product Manual, Rev. EDisable write cache 4.1.3 Set Features commandEE25 Series Product Manual, Rev. E Internet 5.0 Seagate Technology support servicesSeagate Service Centers Warranty SupportAsia/Pacific Support Services Customer Service OperationsUSA/Canada/Latin America support services Europe, the Middle East and Africa Support ServicesIndex NumericsPage Page EE25 Series Product Manual, Rev. E Page 920 Disc Drive, Scotts Valley, California 95066-4544, USA Seagate Technology LLC