Datasheet

1.11 Enclosure Service Interface (ESI)
C141-C008 1-107
ESI INTF
–Parallel_ESI
SEL_ID Discovery Command Read Command Write SEL_ID
Figure 1.62 EIE operation phases
If any errors or timeouts are detected during the EIE operation, the SCSI device
aborts the operation and continues normal operation. Errors are not reported.
1.11.6.3 Enclosure requested information
If the enclosure services interface transfer is initiated by the enclosure, the SCSI
device sends ESI Command Phase information to the enclosure following
successful discovery. The page code in the ESI command is 00h. This page code
is reserved for SCSI diagnostic commands between the host and the SCSI device
and will not appear in ESI transfers initiated by SCSI commands. The ESI
command is a read operation, SEND = 0, with parameter length of 6h.
The enclosure responds to the ESI command from the SCSI device with an ESI
request as defined in Table 1.31. The information requested by the enclosure is
identified by the action code. Table 1.32 defines the action codes.
Table 1.31 Enclosure request
Bit
Byte
7 6 5 4 3 2 1 0
0 Page Code (00h)
1 0 0 0 0 Action Code
2 0 0 0 0 0 0 0 0
Reserved
3 Action Specific
4
5
(MSB) Parameter Length
(LSB)
The parameter length in the enclosure request is set by the enclosure to the
number of bytes it is requesting including the four header bytes. The SCSI device
sends the actual length of the requested information or the length identified in the
request parameter length whichever is less. If the parameter length is equal to 0,
the SCSI device ends the ESI transfer by negating Parallel_ESI.