Fujitsu MAW3073 SERIES, Specifications

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C141-C011 1-139
Table 1.34 System level requirements
Parameter Minimum Maximum
V
A
(except OR-tied signals) (1) -1 V -100 mV
V
N
(except OR-tied signals) (1) 100 mV 1 V
V
A
(OR-tied signals) (1) -3.6 V -100 mV
V
N
(OR-tied signals) (1) 100 mV 125 mV
Attenuation (%) (2) 15
Loaded media impedance (ohms)
(3)
85 135
Unloaded media impedance (ohms) 110 135
Terminator bias (mV) 100 125
Terminator impedance (ohms) 100 110
Device leakage (
µ
A)
-20 20
Number of SCSI devices 2 16
Ground offset level (mV) (4) -355 355
Note:
(1) These are the signal levels at the receiver, the system allows 60 mV crosstalk for calculating the
minimum driver level.
(2) Measured from the driver to the farthest receiver.
(3) Caused by the addition of device capacitive load.
(4) This is the difference in voltage signal commons for SCSI devices on the bus.
1.13 SCSI bus fairness
(1) Fairness Model
Implementation of the SCSI bus fairness is optional.
A SCSI device determines fairness by monitoring prior arbitration attempts by other SCSI devices.
It shall put off arbitration for itself until all lower priority SCSI devices that lost previous
arbitration either win a subsequent arbitration or discontinue their arbitration attempts (e.g., as in
the case where the initiator aborted an outstanding command thus removing the need to re-
arbitrate).
When a SCSI device does not need to arbitrate for the SCSI bus, it shall monitor the arbitration
attempts of the other SCSI devices and refresh the fairness register with the SCSI IDs of any lower
priority SCSI devices that lost arbitration.