SCSI Description
Quantum DLT 4000 Tape Drive
3-21
REQ signal until after the leading edge of the next ACK pulse is received. For
successful completion of the data phase, the number of ACK and REQ pulses
must be equal.
The initiator sends one ACK signal pulse for each REQ pulse received. The ACK
signal can be asserted as soon as the leading edge of the corresponding REQ
pulse has been received.
Drive-to-Initiator Transfer Procedure
1.
The drive sets the DB (7–0, P) signals to the desired values. The DB (7–0,
P) signals are held valid for a minimum of one deskew delay plus one cable
skew delay after REQ is asserted.
2.
Drive delays at least one deskew delay plus a cable skew delay.
3.
Drive asserts the REQ signal for a minimum of one assertion period. Drive
can negate the REQ signal and change or release the DB (7-0, P) signals.
4.
Initiator reads the DB (7-0, P) signals within one hold time of the
transition of the REQ signal to true.
5.
Initiator indicates its acceptance of the data by asserting an ACK pulse.
6.
The drive waits at least the greater or these periods before again asserting
REQ:
c)
A transfer period from the last transition of the REQ signal to true, or
d)
A negation period from the last transition of the REQ signal to false.
7.
The initiator waits at least the greater of these periods before reasserting
ACK:
a)
A transfer period from the last transition of the ACK signal to true, or
b)
A negation period from the last transition of the ACK signal to false.
Initiator-to-Drive Transfer Procedure
Initiator transfers one byte for each REQ pulse received.
1.
Drive asserts the REQ signal.
2.
After receiving the leading edge of the REQ signal, initiator drives the DB
(7–0, P) signals to their desired values. The DB (7-0, P) signals are held
valid for at least one deskew delay plus one cable skew delay plus one hold
time delay after the assertion of the ACK signal.
3.
Initiator delays at least one deskew delay plus a cable skew delay.
4.
Initiator asserts the ACK signal for a minimum of one assertion period.
5.
Initiator can negate the ACK signal and change or release the DB (7-0, P)
signals.
Summary of Contents for DLTtape DLT 4000
Page 1: ...DLT 4000 Tape Drive Product Manual November 10 2003 81 60043 04 ...
Page 5: ...USER MANUAL STATEMENTS FOR CLASS B EQUIPMENT continued ...
Page 6: ......
Page 24: ...About This Manual Quantum DLT 4000 Tape Drive xxiv ...
Page 62: ...Hardware Implementation 2 28 Quantum DLT 4000 Tape Drive ...
Page 100: ...Messages 4 12 Quantum DLT 4000 Tape Drive ...
Page 264: ...SCSI Commands 5 164 Quantum DLT 4000 Tape Drive ...
Page 274: ...Appendix B EEPROM Resident Bugcheck and Event Logs B 6 Quantum DLT 4000 Tape System ...
Page 280: ...Appendix C Updating the Firmware C 6 Quantum DLT 4000 Tape Drive ...
Page 298: ...Index Index 6 Quantum DLT4000 Tape Drive ...
Page 299: ......