49 skew correction range, 50 strobe offset tolerance, 51 system deskew delay – Seagate Ultra 320 User Manual

Page 46: 52 system noise at launch, 53 system noise at receiver, 54 time asymmetry, 55 transmit assertion period, 56 transmit hold time, 57 transmit isi compensation, 58 transmit negation period

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32

Parallel SCSI Interface Product Manual, Rev. A )

pensation.

2.5.49

Skew correction range

The minimum skew correction capability of the receiver of a signal on the DATA BUS or DB(P1) relative to the
ACK or REQ signal as measured at the receiver’s connector. The skew correction range shall be equal to:

+/– [(transmitter chip skew) + (cable skew) + (two times trace skew)]

relative to the corresponding ACK or REQ clock signal for that transition. Receiver chip skew is not included,
as it is internal to the receiver.

2.5.50

Strobe offset tolerance

The time tolerance of centering the compensated REQ or ACK strobe in the transfer period during the training
pattern.

2.5.51

System deskew delay

The minimum time that a SCSI device should wait after receiving a SCSI signal to ensure that asynchronous
transfers at the same time are valid. The system deskew delay shall not be applied to the synchronous trans-
fers or paced transfers.

2.5.52

System noise at launch

The maximum time shift of SCSI bus signals caused by system noise at the transmitter (e.g., noise caused by
current changes in the voice coil) measured at the transmitting SCSI device connector.

2.5.53

System noise at receiver

The maximum time shift of SCSI bus signals caused by system noise at the receiver (e.g., noise caused by
current changes in the voice coil) measured at the receiving SCSI device connector not including the time shift
from the system noise at launch.

2.5.54

Time asymmetry

The maximum time difference between the asserted and negated signal for data, REQ, or ACK transitions that
are intended to be equidistant.

2.5.55

Transmit assertion period

The minimum time that a SCSI target port shall assert the REQ signal while using synchronous transfers or
paced transfers, provided it is not transitioning P_CRCA during data group transfers. Also, the minimum time
that a SCSI initiator port shall assert the ACK signal while using synchronous transfers or paced transfers.

2.5.56

Transmit hold time

For ST data transfers, the minimum time provided by the transmitting SCSI device between the assertion of the
REQ signal or the ACK signal and the changing of the Data Bus, DB(P_CRCA), and/or DB(P1) while using
synchronous data transfers. For DT data transfers, the minimum time provided by the transmitting SCSI device
between the transition of the REQ signal or the ACK signal and the changing of the Data Bus, DB(P_CRCA),
and/or DB(P1).

2.5.57

Transmit ISI compensation

The effective reduction in worst-case ISI timing shift provided by the transmitting SCSI device as seen at the
receiving SCSI device connector.

2.5.58

Transmit negation period

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