Seagate Fibre Channel Interface - Manual (Page 116)

102 Fibre Channel Interface Manual, Rev. D
In case 2, the drive continues the discovery process. The drive waits up to 1 second for the enclosure to assert
the –ENCL_ACK (SEL_4)) low. The time is allowed for the enclosure processor to complete processing other
possible ESI requests through other devices.
If –ENCL_ACK is not asserted within one second, the drive assumes the enclosure has 8067 support but is not
responding. The SCSI diagnostic command is failed with ASC/ASQ 35 02. If ENCL_ACK is detected, the drive
asserts –DSK_WR and –DSK_RD, SEL(6) and SEL(5) respectively, low.
The enclosure is required to respond to –DSK_WR and –DSK_RD by negating –ENCL_ACK within 100 µsec.
The drive responds to the negating of –ENCL_ACK by negating –DSK_WR and –DSK_RD and moving to the
ESI command phase.
Figure 13. Discovery process flow diagram
10.2 8045 mode
In 8045 mode, the enclosure places the binary complement of ESI on the Select_ID pins, SEL_(6:0).
Do bits
SEL_(3:0)
invert in
<1
µsec?
Yes
No
No
Yes
Does
-ENCL_ACK
assert in
<1.2
sec?
Yes
Does
-ENCL_ACK
negate in
<1.2
sec?
Assert -Parallel_ESI
Assert -DSK_RD, -DSK_WR
Negate -DSK_RD, -DSK_WR
The drive:
- assumes enclosure is SFF 8067.
- continues command and data transfer.
The drive:
- assumes enclosure is
SFF 8067 post error 35 02.
No
The drive:
- assumes enclosure is SFF 8045 with Parallel ESI.
- provides ESI information.
Do bits
SEL_(0-7)
change
at all?
Yes
No
The drive:
- assumes enclosure is
SFF 8045 w/o Parallel ESI.
- ASC/ASCQ = 35 01.