Write Full - HP C2488A Technical Reference Manual

Write Full
The WRITE FULL command allows the Initiator to request the Target to write the specified
logical or physical block with the exact block formatting information included with the
command. This information may include the header, data, and ECC field contents.
Caution
I
Byte
00
01
02-05
06
07-08
09
Note
The WRITE FULL command allows the Initiator to directly control the
formatting of a physical block of media. Use of this command should be
restricted to development or other highly controlled environments. The use
of this command may a.dversely affect the reliability of data recovery and
proper device operation at media addresses other than the one specified.
This command is intended strictly to test Target and Initiator reaction
to certain induced media errors. Any use of this command other than at
Hewlett-Packard approved sites and by Hewlett-Packard approved methods
may be deemed a violation of warranty.
Write Ful! Command Descriptor Block (COB)
Bit
7
I
6
I
5
I
4
I
3
I
2
I
1
I
0
Opcode::: FCH
Logical Unit Number
I
Reserved
1
Phys
(MSB:::02) Address (LSB:::05)
Reserved
(MSB:::07, 02H) Byte Transfer Length (LSB:::08,lAH)
Control Byte
For this command to succeed, the header of the sector prior to the requested
sector must be readable.
Using the WRITE FULL command, the Initiator transfers to the Target the compiete
information to write one physical block. A WRITE FULL command is usually preceded by
a READ FULL command, which returns the entire contents (548 bytes) of a specified block.
The Initiator receives the complete READ FULL data, strips off the lO-byte header, and
modifies the block contents as required. The resultant 538 bytes constitute the data phase
of the WRITE FULL command. The WRITE FULL command and the preceding READ
FULL command should both address the same block; thus ensuring that the modified data is
returned to its original location.
6-22
Ven~or
Unique Command Descriptions
DRAFT
1/18/93 09:58