Product manual

C.8 Cache Control page (38
H
)
The Cache Control page is shown below. This table summarizes the
function, the default value and the changeability of each bit.
Bit
Byte
7 6 5 4 3 2 1 0
0 PS (1) Page code (38
H
)
1 Page length (0E
H
)
2 Rsrvd WIE Rsrvd CE Cache table size
default 0 X 0 X X X X X
changeable (00
H
)
3 (default) Prefetch threshold (00
H
)
changeable 00
H
4 (default) Maximum prefetch (FF
H
)
changeable 00
H
5 (default) Maximum prefetch multiplier (00
H
)
changeable 00
H
6 (default) Minimum prefetch (00
H
)
changeable 00
H
7 (default) Minimum prefetch multiplier (00
H
)
changeable 00
H
8–15 (default) Reserved (0000000000000000
H
)
changeable 0000000000000000
H
Byte 2 The cache enable (CE) bit is always the inverse of the RCD bit
in Mode Page 08
H
.
The
write index enable (WIE) bit controls the creation of cache
data on Write commands. If bit 6 is 0, the next command treats
the cache area as empty.
The
cache table size field contains the same values as Mode
Page 08
H
, byte 13, bits 3 through 0.
Byte 3 The
prefetch threshold is not implemented. The drive reads until
the buffer is full upon receipt of a Read command.
Byte 4 The
maximum prefetch field always contains the same value as
byte 9 of the Caching page. The initiator cannot directly change
this byte.
110 ST3655 Family SCSI Drives Product Manual, Rev. A