Fujitsu 80, Scsi Logical Interface Specifications

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4.1 Mode Parameters
C141-C010 4-25
"F" : Data put into the cache during a WRITE or WRITE and VERIFY command was not replaced
if there is ohter data in the cache that was placed into the cache by other means and it may be
replaced.
"1" : Data put into the cache during a WRITE or WRITE and VERIFY command was replaced
sooner than data placed into the cache by other means.
"0" : Indicates the device server was not distinguish between retaining the indicated data and data
placed into the cache memory by other means.
i. Pre-fetch inhibit block count (not supported)
This parameter is used to selectively prohibit data Look-Ahead operations in the READ command or
the READ EXTENDED command. When the "Transfer block count" specified in the CDB of the
READ command or the READ EXTENDED command is greater than the value in this parameter,
data Look-Ahead operations are not executed in that command. This bit cannot be changed. The IDD
disregards the specification in this bit and operates according to the "Default" value (= X 'FFFF').
j. Minimum pre-fetch (not supported)
This parameter specifies the minimum quantity of logical data blocks pre-fetched to the data buffer
with the READ command or READ EXTENDED command.
This parameter cannot be changed. The IDD disregards the specification in this field.
k. Maximum pre-fetch (not supported)
This parameter specifies the maximum quantity of logical data blocks pre-fetched to the data buffer
with the READ command or READ EXTENDED command.
The IDD varies the pre-fetch volume according to the volume of data requested by the READ
command or READ EXTENDED command. The value reported to the MODE SENSE command
always indicates the number of blocks corresponding to 1 cache segment – 1.
This parameter cannot be changed. The IDD disregards the specification in this field.
l. Maximum pre-fetch control block count (not supported)
This parameter specifies the maximum quantity of logical data blocks pre-fetched to the data buffer
with the READ command or READ EXTENDED command. In the IDD the maximum pre-fetch
quantity cannot be limited.
This parameter cannot be changed. The IDD disregards the specification in this field.
m. DRA (Disable Read-ahead) (not support)
This bit specifies whether or not activate the read-ahead operation.
This bit cannot be changed. The IDD disregards the specification in this bit.