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Table A.4 Signal delay times definition (2/2)

No.

Item

Time

Definition

 

 

 

 

10

Disconnection

200 µs

The minimum time that a target shall wait after releasing BSY

 

delay

 

before participating in an ARBITRATION phase when

 

 

 

honoring a DISCONNECT message from the initiator

 

 

 

 

11

Hold time

45 ns

The minimum time added between the assertion of REQ (or

 

 

 

REQB) or ACK (or ACKB) and the changing of the data lines

 

 

 

to provide hold time in the initiator or target while using

 

 

 

synchronous data transfers. REQB and ACKB timings only

 

 

 

apply to optional wide data transfers.

 

 

 

 

12

Negation

90 ns

The minimum time that a target shall negate REQ (or REQB)

 

period

 

while using synchronous data transfers. Also, the minimum

 

 

 

time that an initiator shall negate ACK (or ACKB) while

 

 

 

using synchronous data transfers. REQB and ACKB timings

 

 

 

only apply to optional wide data transfers.

 

 

 

 

13

Power-on to

10 sec

The recommended maximum time from power application

 

selection time

(recom-

until an SCSI target is able to respond with appropriate status

 

 

mended)

and sense data to the TEST UNIT READY, INQUIRY, and

 

 

 

REQUEST SENSE commands

 

 

 

 

14

Reset to

250 ms

The recommended maximum time after a hard RESET

 

selection time

(recom-

condition until an SCSI target is able to respond with

 

 

appropriate status and sense data to the TEST UNIT READY,

 

 

mended)

 

 

INQUIRY, and REQUEST SENSE commands

 

 

 

 

 

 

 

15

Reset hold

25 µs

The minimum time over which RST must be kept asserted

 

time

 

 

 

 

 

 

16

Selection abort

200 µs

The maximum time required from the moment when selection

 

time

 

or deselection of an initiator or target is detected until BSY is

 

 

 

asserted

 

 

 

 

17

Selection

250 ms

The minimum time required for an initiator or target in the

 

timeout delay

(recom-

selection or deselection phase to wait for a BSY response

 

 

mended)

before it starts the timeout procedure

 

 

 

 

18

Transfer period

-

The minimum allowable period, during sync data transfer,

 

 

 

between the start of consecutive REQ pulses and the start of

 

 

 

consecutive ACK pulses

 

 

 

 

Appendix A-10