HP C2246 Technical Reference Manual page 139

Read Full
Read Full Header Format
The physical block returned by the Target is preceded by a 10-byte header.
Bit
Byte
7
I
6
I
5
I
4
I
3
I
2
I
1
I
0
00
Total A va.ila.ble Length (MSB)
=
02H
01 Total Available Length (MSB)
=
22H
02 Field Descriptor
=
001
I
Field Length (MSB)
=
OOH
03 Field Length (LSB)
=
06H
04
Field Descriptor
=
010
I
Field Length (MSB)
=
02H
05
Field Length (LSB}
OOH
06 Field Descriptor
=
100
l
Field Length {MSB)
=
OOH
07
Field Length {LSB)
=
14H
08 Field Descriptor
=
000
I
Field Length (MSB) =OOH
09 Field Length (LSB) OOH
Read Full Physical Block Contents
Bit
Byte 7
I
6
I
5
I
4
I
3
I
2
I
1
I
0
10-15 Header Bytes/Header CRC
16-527 Data Bytes
528-547
ECC Bytes/Data CRC
Total Available Length. This field contains the number of bytes that the device can return for
this command. The length does not include itself but does include the remaining eight bytes
of the header. If the Allocation Length field in the CDB is smaller than the Total Available
Length, the Total Available length is not adjusted to show the truncation.
Field Descriptor. The bit code values are defined as follows:
• 001 - Physical Block Header Field
• 010 - User Data Field
• 100
~
Error Correction/Detection Field
• 000 - End Fields Mark
Field Length. The individual fields define the number of bytes to follow them in the
associated field. The Field Length for the End Fields Mark is set to zero.
The physical block consists of 538 bytes: 6 bytes of header, 512 (maximum) bytes of data, and
20 bytes of data ECC. No error correction is applied to the data bytes returned.
Vendor Unique Command Descriptions B-19