4.4.13MODE SENSE (6)

The normal MODE SENSE (6) sequence for the scanner is as follows:

Proce>

Bus phase

Initiator operation

¨Æ

Target operation

dure

 

 

 

 

 

 

 

 

 

1

Bus Free

Checks Bus Free

 

 

 

 

 

 

 

2

(Arbitration)

Acquires the bus use right

 

 

 

 

 

 

 

3

Selection

Selects the target

Æ

 

 

 

 

 

 

 

 

 

 

Drives the BSY signal

 

 

 

 

 

4

(Message Out)

Selects the logical device

Æ

 

 

 

 

 

 

5

Command

Specifies MODE SENSE (6)

Æ

 

 

 

(CDB)

 

 

 

 

 

 

Reports mode data

6

Data In

Reports MODE SENSE

¨

 

 

parameter data

 

 

 

 

 

 

 

7

Status

 

¨

Reports GOOD status

 

 

 

 

 

8

Message In

 

¨

Reports message

 

 

 

 

(Command complete)

 

 

 

 

 

 

 

 

 

Releases the BSY

 

 

 

 

signal

 

 

 

 

 

9

Bus Free

 

 

 

 

 

 

 

 

(1)MODE SENSE (6) command: Command phase (Initiator to Target)

The MODE SENSE (6) command is used for the target to report mode parameters to the initiator.

The command descriptor block (CCD) is as follows:

 

7

6

5

4

3

2

1

0

Byte 0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Operation code X©1A￿

 

 

 

1

Logical unit

 

 

Reserved

DBD

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

2

 

PC

 

 

 

Page code

 

 

3

 

 

 

 

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

 

 

 

 

Allocation length

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5

 

 

 

 

 

Control byte

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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