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Cdb fields – HP C737990900 User Manual

Page 161

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Commands 161

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CDB Fields:

Mode

This field can be set to one of the following values:

00000b The drive transfers a 4-byte header from the host (which should be set to zeros),

followed by (allocation length

-

4) bytes of data. The data is written into the buffer

identified by the Buffer ID, starting from offset zero in the buffer.

The Buffer ID and Buffer Offset must both be zero. Allocation Length must not exceed

(buffer size + 4).

00010b The drive transfers allocation length bytes of data from the host, bytes of data which is

placed in the buffer indicated by Buffer ID, starting from Buffer Offset from the start of

the buffer. No header is sent.

The Buffer Offset and Allocation Length must be kept within the buffer size, and the

Buffer ID must to set to one of the valid values.

00100b This mode is used to transfer new firmware to the drive. The drive receives Allocation

Length bytes of data from the host. The data is stored in the drive’s buffer.The location in

the buffer at which the data is written is determined by the firmware.

The firmware image is divided into a number of blocks of data which are sent to the

drive using multiple Write Buffer commands.

All the firmware image data should be transferred using this mode.

The Buffer ID and Buffer Offset are ignored.

00101b This mode is used to indicate that the complete firmware image has been sent to the

drive. This is the signal for entering the FLASH reprogramming stage of the firmware

upgrade process.

Once this command has been received, and the associated data stored in the buffer, the

resident firmware checks the validity of the image that has been received. If this seems to

be correct, the Firmware Upgrade operation will commence. If any faults are detected in

the format of the image, the drive will report

CHECK CONDITION

to the host. The sense

key is

ABORTED COMMAND

, and the additional sense is set to 2600h (invalid field in

parameter list).

Caution

Once this command has been sent and completed, the drive’s power supply

must not be interrupted until the drive has completed the firmware upgrade.

The Buffer ID and Buffer Offset are ignored.

01010b This mode is used to write to the 4KB Echo Buffer.

The Buffer ID and Offset are ignored.