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Truncating Pages An EEPROM option enables you to choose

whether the Allocation Length is checked for values that would

cause the Parameter List Header, Block Descriptor, or one of the

parameter pages to be truncated. With the EEPROM option, you

can choose to disallow or permit truncated pages (see the “MODE

SELECT and MODE SENSE” option on page A-11).

To understand how a truncated page might occur, consider the

following example: Suppose you set the Page Code to 20h (for

Vendor Unique Parameters Page 1), the DBD bit to 0 (to send the

Block Descriptor), and the Allocation Length to 11h (17 bytes).

These values cause the CTS to return the entire Parameter List

Header (4 bytes), the entire Block Descriptor (8 bytes), and 5 of the

6 available bytes for Vendor Unique Parameters Page 1. The

result of specifying such a value depends on the EEPROM image

as follows:

When the EEPROM option is set to disallow truncated pages

(default), the CTS returns the requested information, then

terminates the command with Check Condition status. The

sense key is set to Illegal Request and the Additional Sense

Code is set to Parameter List Length Error.

When the EEPROM option is set to permit truncated pages,

the CTS returns the requested information, including the

truncated page, without issuing an error.

Restrictions for MODE SENSE Data:

In non-page format, for any data transfer greater than 0 bytes,

the entire 4-byte Parameter List Header must be received from

the CTS. That is, the entire 4-byte Parameter List Header must

be received before the Block Descriptor or any vendor-unique

parameters can be received.

In non-page format, if the Block Descriptor is requested, it

must be received in its entirety (that is, all 8 bytes).

In page format, if the EEPROM option is set to disallow

truncated pages (see explanation above), the value for the

Allocation Length byte must be equal to or greater than the

total number of bytes to be transferred from the CTS to the

initiator.

Byte 05, Bits 7 and 6 - Vendor Unique

There are no vendor unique definitions for these bits.

10-12

EXB-8205 and EXB-8505

(Standard and XL)

510503

10 MODE SELECT (15h) and MODE SENSE (1Ah)

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Exabyte EXB-8205 Betriebsanleitung Seite 168