Transmitter Pre-Compensation With Cutback; Free Running Clock (Frc); Skew Compensation; Information Unit Transfers - Maxtor ATLAS 10K IV User Manual

6.17.7

Transmitter Pre-Compensation with Cutback

This is an open-loop method of compensating for some of the signal loss that is most
severe on the first part of a signal's transition.
6.17.8

Free Running Clock (FRC)

FRC is used to improve integrity of the clock signal by removing inter-symbol
interference (ISI). By having a clock running at a constant neutralized. The free
running clock is restricted for use with DT information unit transfers at 320
megabytes per second.
6.17.9

Skew Compensation

Skew compensation of data signals relative to the clock signal; an Ultra320 SCSI
device can establish skew compensation simultaneously for each of the received
transitions on the data lines so that they occur at the correct time relative to the clock.
6.17.10

Information Unit Transfers

IUT (or "IU Transfers," also known as "packetized transfers") is a method to
encapsulate non-data information (like commands sent from the initiator to the target
and status sent from the target to the initiator) into packets and transfer those packets
at the maximum negotiated data rate of up to 320 megabytes per second. A method
to transfer packets for a number of I/O processes without an intervening physical
disconnection. A method to minimize overhead by eliminating several bus phase
changes per I/O process.
6.18

HOT PLUGGING/REMOVAL AND INSERTION OF SCSI DEVICES

The Maxtor Atlas 10K IV SCA low voltage differential (LVD) disk drives are
designed for use in "Hot Swap" applications within a properly designed and
configured SCSI system. With care, system integrators can design storage arrays and/
or SCSI buses using Maxtor Atlas 10K IV disk drives that are "Hot Swap Case 4"
tolerant.
Case 4 is defined as follows:
• Devices are powered and the bus may have active I/O processes
ongoing, but the device being removed or inserted must be idle (no
ongoing I/O processes during the insertion/removal).
• Ground connections to the drive must be made and maintained for 1
millisecond before, during, and 1 millisecond after the insertion/
removal. The SCA-2 connector used on the Maxtor Atlas 10K IV disk
drive meets this requirement.
• Device circuitry connected to bus pins must remain "glitch" free during
power up or power down.
Note:
PRELIMINARY 02/19/03
In a multimode environment, any insertion or removal that changes
the bus mode causes a transceiver mode change reset event.
Feature Descriptions
Maxtor Atlas 10K IV 6-13