Seagate Ultra 160 ユーザーズマニュアル

160  

                                                     

 Parallel SCSI Interface Product Manual, Rev. A 

c. A SCSI device being removed shall maintain its power ground and logic ground prior to, during, and for 

at least 1 ms after the disconnection of any device connector contact from the SCSI bus.

d. The SCSI device being removed or inserted shall employ transceivers that conform to the applicable 

requirements in ANSI SPI-5 specification, T10/1525D, sections 7.2.2 and 7.3.5.3 for glitch-free powering 
on and off. The SCSI device shall maintain the high-impedance state at the device connector contacts 
during a power cycle until the transceivers are enabled. Power cycling includes on board TERMPWR 
cycling caused by plugging, and SCSI device power cycling caused by plugging and switching.

Any on-board switchable terminators as well as SCSI device transceivers may affect the impedance 
state at the device connector contacts.

e. The SCSI device power may be simultaneously switched with the SCSI bus contacts if the power distri-

bution system is able to maintain adequate power stability to other SCSI devices during the transition 
and the grounding requirements in items (b) and (c) above are met.

f. The SCSI bus termination shall be external to the SCSI device being inserted or removed.
g. Initiation or resumption of I/O processes for a newly inserted or removed SCSI device is vendor-specific 

but shall not occur sooner than 200 milliseconds after the completion of the insertion or removal event.

h. Bypassing capacitors connecting to the TERMPWR line on the SCSI device being inserted or removed 

shall not exceed 10 mF. For single-ended applications, SCSI bus terminations shall use voltage regula-
tion.

In a multimode environment, any insertion or removal that changes the bus mode causes a transceiver 
mode change reset event (see Section 5.4.4).

LVD SCSI devices may require more stringent system design to tolerate transients that occur during 
Case 4 insertion or removal.

This section contains a mapping of terminology used in SCSI-2 to the terminology used in this manual (see 
Table 69).

abort task

abort tag

abort task set

abort

cable skew

cable skew delay

clear task set

clear queue

head of queue

head of queue tag

ordered

ordered queue tag

simple

simple queue tag

target reset

bus device reset

task

I/O process

task complete

command complete

task set

queue