Seagate Ultra 160 ユーザーズマニュアル
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Parallel SCSI Interface Product Manual, Rev. A
3.7.3
DT DATA OUT phase
The DT DATA OUT phase allows the SCSI target port to request that data be sent from the SCSI initiator
device to the SCSI target device using DT data transfers. The target shall assert the MSG signal and negate
the C/D and I/O signals during the REQ/ACK handshakes of this phase.
device to the SCSI target device using DT data transfers. The target shall assert the MSG signal and negate
the C/D and I/O signals during the REQ/ACK handshakes of this phase.
3.7.4
ST DATA IN phase
The ST DATA IN phase allows the SCSI target port to request that data be sent to the initiator from the target
using ST data transfers. The target shall assert the I/O signal and negate the C/D and MSG signals during the
REQ/ACK handshake(s) of this phase.
using ST data transfers. The target shall assert the I/O signal and negate the C/D and MSG signals during the
REQ/ACK handshake(s) of this phase.
3.7.5
ST DATA OUT phase
The ST DATA OUT phase allows the SCSI target device to request that data be sent from the SCSI initiator
device to the target device using ST data transfers. The SCSI target port shall negate the C/D, I/O, and MSG
signals during the REQ/ACK handshakes of this phase.
device to the target device using ST data transfers. The SCSI target port shall negate the C/D, I/O, and MSG
signals during the REQ/ACK handshakes of this phase.
3.8
STATUS phase
3.8.1
STATUS phase description
The STATUS phase allows the SCSI target device to request that a status byte be sent from the target to the
SCSI initiator device.
SCSI initiator device.
The SCSI target port shall assert the C/D and I/O signals and negate the MSG signal during the REQ/ACK
handshake of this phase.
handshake of this phase.
A QAS-capable SCSI initiator port shall wait a minimum of one QAS non-data phase REQ(ACK) period to
assert ACK after detecting the assertion of REQ.
assert ACK after detecting the assertion of REQ.
A QAS-capable SCSI initiator port shall assert ACK for a minimum of one QAS non-data phase REQ(ACK)
period.
period.
3.8.2
STATUS phase exception condition handling
If the initiator detects a parity error on the status byte, the initiator shall create an attention condition. When the
target switches to a MESSAGE OUT phase, the initiator should send a SCSI initiator port Detected Error mes-
sage (see Section 4.3.5) to the target. This message notifies the target that the Status byte was invalid.
target switches to a MESSAGE OUT phase, the initiator should send a SCSI initiator port Detected Error mes-
sage (see Section 4.3.5) to the target. This message notifies the target that the Status byte was invalid.
3.9
MESSAGE phase
3.9.1
MESSAGE phase overview
The MESSAGE phase is a term that references either a MESSAGE IN or a MESSAGE OUT phase. Multiple
messages may be sent during either phase. The first byte transferred in either of these phases shall be either
a single-byte message or the first byte of a multiple-byte message. Multiple-byte messages shall be wholly
contained within a single MESSAGE phase.
messages may be sent during either phase. The first byte transferred in either of these phases shall be either
a single-byte message or the first byte of a multiple-byte message. Multiple-byte messages shall be wholly
contained within a single MESSAGE phase.
3.9.2
MESSAGE IN phase
The MESSAGE IN phase allows the SCSI target port to request that messages be sent to the SCSI initiator
port from the SCSI target port.
port from the SCSI target port.
The SCSI target port shall assert the C/D, I/O, and MSG signals during the REQ/ACK handshakes of this
phase.
phase.
A QAS-capable SCSI initiator port shall wait a minimum of one QAS non-data phase REQ(ACK) period to
assert ACK after detecting the assertion of REQ.
assert ACK after detecting the assertion of REQ.