Datasheet

1.11 Enclosure Service Interface (ESI)
C141-C008 1-103
COMMAND bytes length is always four bytes.
• Page code in byte 0 is defined as SES page for communicating with the
enclosure.
• Bit 0 in byte 1 defines the direction of the data transfer.
0 …… from the drive to the enclosure
1 …… from the enclosure to the drive
• Parameter Length in byte 2 and byte 3 defines data length. The value “0000h”
is used when receiving the data (Receive Diagnostic Result command).
(3) Byte/bit alignment
The COMMAND and READ/WRITE data are transferred in the following alignment.
(Figure 1.58)
byte number ; #0 #1 …… #n-1 #n
byte transfer order in ESI ; 1st 2nd n-1 th n th
bit ; 7 6 5 4 3 2 1 0
transfer order in ESI ;
1st nibble 2nd nibble
bit alignment ; D (3) D (2) D (1) D(0) D (3) D (2) D (1) D (0)
Figure 1.58 Byte/bit alignment in ESI
1.11.4 READ/WRITE phase
(1) READ phase
READ phase is a process that the drive receives the information stored by the
enclosure.
(a)
–DSK_RD
D (0:3)
–ENCL_ACK
min 100 nsec
(c)
(b) (d)
Figure 1.59 READ phase