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C.2 settings for the qas, dt, and iu fields – Quantum 10K II User Manual

Page 365

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Appendix C. Negotiated Rate Information Page Reference

C–2

Quantum Atlas 10K II Ultra 160/m SCSI Hard Disk Drives

Table C–2 Transfer Period Factor Field Values When PARL = 0

Code

Description

00h – 09h

Reserved.

0Ah

Transfer period = 25 ns (Fast-40 data is latched every 25 ns).

0Bh

Transfer period = 30 ns (Fast-40 data is latched every 30 ns).

OCh

Transfer period = 50 ns (Fast-20 data is latched using a transfer period of less than or
equal to 96 ns and greater than or equal to 50 ns).

0Dh – 18h

Transfer period = the period factor x 4 (Fast-20 data is latched using a transfer period
of less than or equal to 96 ns and greater than or equal to 50 ns).

19h – 31h

Transfer period = the period factor x 4 (Fast-10 data is latched using a transfer period
of less than or equal to 196 ns and greater than or equal to 100 ns).

32h - FFh

Transfer period = the period factor x 4 (Fast-5 data is latched using a transfer period
of less than or equal to 1020 ns and greater than or equal to 200 ns).

C.2

SETTINGS FOR THE QAS, DT, AND IU FIELDS

Table C-3 provides valid bit combinations for the QAS, DT, and IU fields of the INQUIRY
command’s Negotiated Rate Information Page (Section 5.11.2.7 of this manual). Only the
combinations shown in the table are valid; all other combinations are reserved.

Table C–3 Settings for the QAS, DT, and IU Fields of the Negotiated Rate Information Page

(INQUIRY Command)

QAS

DT

IU

Description

0

0

0

Selects Single Transition phases. Use ST DATA IN and ST DATA OUT phases to
transfer data

0

1

0

Use DT DATA IN and DT DATA OUT phases with data group transfers.

0

1

1

Use DT DATA IN and DT DATA OUT phases with information unit transfers.

1

1

1

Use DT DATA IN and DT DATA OUT phases with information unit transfers and
use QAS for arbitration.