Fujitsu MAW3073 SERIES Specifications page 40

a) The device is capable of logical operation for at least 100 ms, and
Notes:
The 100 ms delay allows time for the DIFFSENS pin to connect after the initial power
connection (in the case of insertion of a device into an active system), or allows time for
the power distribution system to settle.
b) The DIFFSENS mode detected has remained stable for an additional 100 ms after a) is
achieved.
A device shall not change its present signal driver or receiver mode based on the DIFFSENS
voltage level unless a new mode is sensed continuously for at least 100 ms.
(3) MATED Signals
If MATED 1 and MATED 2 signals are not mated then one or more short pins are not mated. If
MATED 1 and MATED 2 signals are mated then the mated condition of the short pins is
indeterminate. The MATED 1 and MATED 2 signals may indicate to the SCSI device that the
SCSI device is seated in an SCA-2 connector and it may begin power on processing. The signal
requirements are indicated below, but may be met by the circuit.
a) MATED 2/Drive Side
The signal is attached to signal ground on the SCSI device side.
b) MATED 2/Backplane Side
The signal is attached either directly or through optional logic in such a manner that the
MATED 1 signal is held to a ground level when the MATED 2 connection is completed. The
SCSI device shall sink no more than 100 mA to ground through the MATED 2 pin if optional
logic is used.
c) MATED 1/Drive Side
The MATED 1 signal shall be sensed by the SCSI device. When the MATED 1 connection is
determined to be at a ground level, the SCSI device may assume that the SCSI device has been
partially mated. Assuming the mating process continues uninterrupted until competition,
including sensing of the SCSI ID Selection signals and the motor start controls, then normal
power on procedures may begin 250 msec after the MATED 1 signal is observed to transition
to the ground level. When the MATED 1 connection is determined to be at the open level, the
SCSI device is not mated. The MATED 1 signal is tied up to a TTL positive level when the
SCSI device is not installed. If the SCSI device is mated and operating, it may optionally
detect the open level of MATED 1 as an indication that the SCSI device is partially unmated
and may be about to be removed. If the SCSI device supports detection of the open level of
MATED 1 to prepare itself for power removal or for physical removal from the enclosure, the
detection shall occur within 1 second from the time that the Mated 1 open level occurs at the
SCSI device.
1-22 C141-C011