Question, driving the DATA BUS

JOJO jojo at
Fri Feb 9 09:51:56 PST 1996

* From the SCSI Reflector, posted by:
* JOJO <jojo at>

>From one of our hardware people I have the following questions:

Signal restrictions between phases.

When the SCSI bus is between two information transfer phases, the SCSI-3 chapter
10.11 a) and b) lists the restrictions that shall apply to the SCSI DATA bus. 
However, it doesn't say for how LONG the initiator shall DELAY driving the data 
bus when the target switches the data bus direction from in (target driving) to 
out (initiator driving).

May the initiator drive the bus BEFORE it receives the first SCSI REQ from the 

For how long must the initiator delay driving the bus when the bus phase is 
switching from data in to data out?

Best regards,
Jorgen Johanson

Jorgen Johanson            jojo at
P.O Box 134 Kjelsas
N-0411 Oslo, NORWAY

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