Supported Ata Commands; Execute Drive Diags (90H); Idle Immediate (E1H); Standby Immediate (E0H) - Seagate STT20000A Product Manual

Chapter 5

Supported ATA Commands

Execute Drive Diags (90h)

Idle Immediate (E1h)

Standby Immediate (E0h)

Check Power Mode (E5h)

Sleep (E6h)

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information. If you do not program this register correctly, the drive "hangs" in the
BSY state. To correct this problem, reset operations.
The ATA commands are briefly described in the following paragraphs.
This command is executed regardless of the state of the DRV bit. The command
causes an actual microprocessor reset (drive loses all logical position information).
Power-up diagnostics are performed, and the PDIAG/DASP handshake is
performed per ATA-2 specification. The master device will generate an interrupt.
This command causes the device to set its Power Mode state to Idle and to
generate an interrupt. Although the drive has no actual power saving features, this
command is emulated for software compatibility.
This command causes the device to set its Power Mode state to Standby and to
generate an interrupt. Although the drive has no actual power saving features, this
command is emulated for software compatibility.
This command causes the device to return its Power Mode state in the Int Reason
register, and generate an interrupt. If the drive is in Standby mode, this command
returns 00h in the Int Reason register, otherwise this command returns FFh in the
Int Reason register (indicating IDLE mode).
Previous Cmd
Reset/Power-up
Standby Immed.
Idle Immediate
Any Other Cmd
This command is treated as an Idle command and does NOT prevent the drive from
responding to further commands.
Int Reason
FFh (Idle)
00h (Standby)
FFh (Idle)
FFh (Idle)
ATAPI Interface
STT20000A Product Manual