MODE SELECT15h/55h

MODE SELECT is used to send configuration data to the drive. Both 6-byte and 10-byte versions of the command are supported.

The Mode Select parameter list is transferred from the host to the drive during the data-out phase. It contains zero or more bytes of information. If any information is sent, it should consist of a Mode Parameter Header followed by zero or more mode select pages. Internal parameters are set according to the values specified in the header and pages. Fields in the parameter list are checked and the operation will terminate if an error is found.

NOTE: The drive does not check that the parameter list is correct before modifying internal parameters. The list is checked as the operation proceeds, so if there is an error in the list, all parameters up to that point will be set to their new values, but the parameter in error and later parameters will not be updated.

Pre-execution checks:

Illegal Field

Reservation

Deferred Error

Unit Attention

NOTE: Failure to flush write-behind data will be reported as a Deferred Error.

The parameter list length must be such that only “entire” parts of a parameter list are sent. It is illegal to send a partial mode parameter header, a partial mode block descriptor or a partial mode page. If this happens, then CHECK CONDITION status is reported. The sense key is set to ILLEGAL REQUEST. The additional sense is set to 1A00h (parameter list length error).

Extra checks may be performed on the data, see the descriptions for the parameter list for more details.

Command descriptor block

6-Byte version

 

7

6

5

 

4

 

3

2

1

0

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

Operation

Code (15h)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

Reserved (0)

 

 

PF

 

 

Reserved (0)

 

SP (0)

 

 

 

 

 

 

 

 

 

 

 

2

 

 

 

 

Reserved (0)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

 

 

 

Reserved (0)

 

 

 

 

 

 

 

 

 

 

 

 

4

 

 

 

Parameter List Length

 

 

 

 

 

 

 

 

 

 

 

 

 

5

 

 

 

 

Control

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Commands

MODE SELECT 15h/55h 71