Datasheet

1.11 Enclosure Service Interface (ESI)
C141-C008 1-105
START_1/START_2
1 sec max device dela
y
100 nsec min enclosure dela
y
1 usec max enclosure dela
y
–PARALLEL ESI
–DSK_WR
SEL_6
–DSK_RD
SEL_5
D(0:3)
SEL_(0:3)
1 second max enclosure dela
y
–ENCL_ACK
SEL_4
–SEL_ID (0:3)
*1 *2 *3 *4 *5
*1 Enclosure Services Processor changes START_1 and START_2 to indicate
that it is requesting communication with the SCSI device.
*2 SCSI device asserts –PARALLEL ESI to indicate it is ready to begin
communication with the Enclosure Services Processor.
*3 SCSI device determines that enclosure is SFF-8067 compliant by noting that
SEL_(0:3) bits have inverted and that SEL_5 and SEL_6 have the value that
the device is presenting.
*4 The Enclosure Services Processor returns START_1 and START_2 to Case2,
3, or 4.
*5 The Enclosure Services Processor asserts –ENCL_ACK and discovery
continues.
Figure 1.60 Enclosure initiated ESI request
If discovery determines the enclosure does not support an 8067 capable interface
or the enclosure has driven the START_1 and START_2 signals to an unmated
condition and does not return the START_1 and START_2 signals to a valid
mated condition, the device negates –PARALLEL_ESI and prepares for power
removal. Figure 1.61 shows a case where the enclosure does support 8067 ESI
transfer but the enclosure is requesting the device to prepare for removal.
(This drive does not support this function.)