Maxtor Atlas SCSI Drive 15K II, Product Manual

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Maxtor Atlas 15K B-1
Appendix B
NEGOTIATED RATE INFORMATION
PAGE REFERENCE
This appendix provides information about the INQUIRY command’s Negotiated
Rate Information Page that is not provided in Section 5.11.2.7. Specifically, it
provides the codes and meanings for the Transfer Period Factor field (byte 4) and a
table that explains the allowable settings for the QAS, DT, and IU fields (bits 2, 1,
and 0, respectively, of byte 7).
B.1 TRANSFER PERIOD FACTOR FIELD
Table B-1 provides the codes and meanings allowed for the Transfer Period Factor
field if the value of PARL (Parallel Protocol, bit 2 of byte 6 of the Negotiated Rate
Information Page) is 1.
Table B-2 provides the allowable codes when the value of PARL = 0.
Table B-1 Transfer Period Factor Field Values When PARL = 1
Code Description
00h – 08h Reserved.
09h Transfer period = 12.5 ns (Fast-80 is latched every 12.5 ns). This code is valid only
if the protocol options bits (QAS, DT, and IU) of the page have values selected that
support double transition (DT) data transfers.
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).