Quantum Instruments DLT 7000 - Manual (Page 72)

SCSI Description
3-8 Quantum DLT 7000 Tape System
Table 3–4 SCSI Bus Timing Values (continued)
Timing Description Value Description
Bus Clear Delay 800 ns Maximum time for a SCSI device to stop driving all
bus signals after:
1. BUS FREE is detected. 2.
SEL is received from another SCSI device during
ARBITRATION. 3.
Transition of RST to true.
For condition 1, the maximum time for a SCSI device
to clear the bus is 1200 ns (1.2
µ s) from BSY and SEL
first becoming both false.
If a SCSI device requires more than a bus settle delay
to detect BUS FREE, it clears the bus within a bus clear
delay minus the excess time.
Bus Free Delay 800 ns Maximum time a SCSI device waits from its detection
of BUS FREE until its assertion of BSY when going to
ARBITRATION.
Bus Set Delay 1.8 µs Maximum time for a device to assert BSY and its SCSI
ID bit on the DATA BUS after it detects BUS FREE to
enter ARBITRATION.
Bus Settle Delay 400 ns Minimum time to wait for the bus to settle after
changing certain control signals as called out in the
protocol definitions.
Cable Skew Delay 10 ns Maximum difference in propagation time allowed
between any two SCSI bus signals measured between
any two SCSI devices.
Data Release Delay 400 ns Maximum time for an initiator to release the DATA
BUS signals following the transition of the I/O signal
from false to true.
Deskew Delay 45 ns Minimum time required to wait for all signals
(especially data signals) to stabilize at their correct,
final value after changing.
Disconnection Delay 200 µs Minimum time that a drive waits after releasing BSY
before participating in an ARBITRATION when
honoring a DISCONNECT message from the initiator.