Seagate STT20000A, Product Manual

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ATAPI Interface Chapter 5
STT20000A Product Manual Page 31
ATAPI interface
Introduction
The STT20000A provides an ATA Packet Interface (ATAPI) controller for
communications between the host computer and the drive. The drive supports the
QIC-157 standard interface.
The STT20000A provides a connection between the driver/card and the component
of the PC. Refer to chapter 3 for specific cabling and connector information.
Note: Refer to the QIC-157 Standard for detailed information about the this
interface.
This chapter clarifies the use of several ATA-2 signals and ATAPI commands that
are either vague or optional in the QIC-157 specification.
ATA-2 Interface
The information about the ATA-2 interface is presented in the following topics: ATA-
2 Signals, ATA Registers, and ATA Commands.
ATA-2 Signals
Only the DASP and PDIAG- signals are described in the following paragraphs.
DASP-
This signal is used during power-up handshake sequences for master/slave
identification per ATA-2 specifications.
Because the device has its own front-panel activity LED, this signal is not driven by
this device (to indicate activity) after power-up is complete.
PDIAG-
This signal is used during power-up handshake sequences for master/slave
identification per ATA-2 specifications.
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