TAPE UNIT SCSI COMMANDS

M2488 PRODUCT GUIDE

same as the current parameters will not result in any change or the reporting of a Unit Attention to other initiators. In any case, a Unit Attention condition due to mode parameters being changed will not be generated for the initiator that performed the MODE SELECT command.

4-3.12.2 Mode Select Data

The Mode Select data to be sent by the initiator should be in the form of a four-byte header, fol- lowed by a zero or an eight-byte block descriptor, followed by zero or more variable length pages. The following table illustrates the format of the Mode Select parameter list:

Table 4-43. MODE SELECT Parameter List Format

BITS

BYTES

7

6

5

4

3

2

1

0

0 - n

Mode Parameter Header (4 bytes). See Table 4-44.

0 - n

Block Descriptor (0 or 8 bytes). See Table 4-47.

0 - n

Pages. See Table 4-49.

Mode Select Parameter List Header:

Table 4-44. MODE SELECT Parameter Header

 

 

 

 

 

 

 

 

BITS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BYTES

7

6

 

5

 

4

 

3

 

2

 

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

 

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

0

 

Buffered Mode

 

 

 

 

 

Speed

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Block Descriptor Length (00h or 08h)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 4-45. MODE SELECT Parameter Header Field Description

BYTE

BIT

VALUE

DESCRIPTION

 

 

 

 

2

0-3

 

The Speed field is ignored since the attached peripherals support only a

 

 

 

single speed.

 

 

 

 

2

4-6

0h-7h

The Buffered Modes are described in Table 4-46.

 

 

 

 

3

0-7

 

A single block descriptor may be specified. The Block Descriptor Length

 

 

 

specifies the length in bytes (8) of the block descriptor, if included.

 

 

 

 

4-52

CG00000-011503 REV. A

April 1997

Page 134
Image 134
Fujitsu M2488 manual Mode Select Data, Mode Select Parameter List Format, Mode Select Parameter Header Field Description