Seagate ST39102LC Product Manual - Page 58

REQ/ACK offset - drive type

Page 58 highlights

48 Cheetah 9LP Product Manual, Rev. C 9.5 Synchronous data transfer 9.5.1 Synchronous data transfer periods supported Table 11 and Section 9.5.2 list Synchronous Data transfer periods supported by the drive. The data transfer period to be used by the drive and the initiator is established by an exchange of messages during the Message Phase of operation. See the section on message protocol in the SCSI Interface Product Manual, part number 77738479. Table 11: Synchronous data transfer periods M (decimal) 10 12 25 50 Transfer period (nanoseconds) 25 50 100 200 Transfer rate (megatransfers/second) 40.01 20.0 10.0 5.0 1. This transfer rate is only allowed when using the LVD interface. 9.5.2 REQ/ACK offset The maximum value supported by the Cheetah 9LP family drives for REQ/ACK offset is 15 (0Fh). 9.6 Physical interface This section describes the connectors, cables, signals, terminators and bus timing of the DC and SCSI I/O interface. See Section 9.8 and Section 9.9 for additional terminator information. Figures 12 and 13 show the locations of the DC power connector, SCSI interface connector, drive select headers, and option select headers. Details of the physical, electrical and logical characteristics are given in sections following, while the SCSI operational aspects of Seagate drive interfaces are given in the SCSI Interface Product Manual, part number 77738479. 9.6.1 DC cable and connector ST39102LW and ST34502LW drives receive DC power through a 4 pin connector (see Figure 14 for pin assignment) mounted at the rear of the main PCBA. Recommended part numbers of the mating connector are listed below, but equivalent parts may be used. Type of cable 14 AWG Connector MP 1-480424-0 Contacts (20-14 AWG) AMP 60619-4 (Loose Piece) AMP 61117-4 (Strip) ST39102LC and ST34502LC drives receive power through the 80-pin I/O connector. See Tables 15 and 16.

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48
Cheetah 9LP Product Manual, Rev. C
9.5
Synchronous data transfer
9.5.1
Synchronous data transfer periods supported
Table 11 and Section 9.5.2 list Synchronous Data transfer periods supported by the drive. The data transfer
period to be used by the drive and the initiator is established by an exchange of messages during the Message
Phase of operation. See the section on message protocol in the
SCSI Interface Product Manual,
part number
77738479.
Table 11:
Synchronous data transfer periods
9.5.2
REQ/ACK offset
The maximum value supported by the Cheetah 9LP family drives for REQ/ACK offset is 15 (0Fh).
9.6
Physical interface
This section describes the connectors, cables, signals, terminators and bus timing of the DC and SCSI I/O
interface. See Section 9.8 and Section 9.9 for additional terminator information.
Figures 12 and 13 show the locations of the DC power connector, SCSI interface connector, drive select head-
ers, and option select headers.
Details of the physical, electrical and logical characteristics are given in sections following, while the SCSI
operational aspects of Seagate drive interfaces are given in the
SCSI Interface Product Manual
, part number
77738479.
9.6.1
DC cable and connector
ST39102LW and ST34502LW drives receive DC power through a 4 pin connector (see Figure 14 for pin
assignment) mounted at the rear of the main PCBA. Recommended part numbers of the mating connector are
listed below, but equivalent parts may be used.
ST39102LC and
ST34502LC drives receive power through the 80-pin I/O connector. See Tables 15 and 16.
M (decimal)
Transfer period
(nanoseconds)
Transfer rate
(megatransfers/second)
10
25
40.0
1
1.
This transfer rate is only allowed when using the LVD interface.
12
50
20.0
25
100
10.0
50
200
5.0
Type of cable
Connector
Contacts (20-14 AWG)
14 AWG
MP 1-480424-0
AMP 60619-4 (Loose Piece)
AMP 61117-4 (Strip)