C141-E124-01EN 3 - 129
3.4.5 READ LONG (3E)
Bit
Byte 76543210
0X‘3E’
1 LUN 000
CORRCT 0
2 Logical Block Address (MSB)
3 Logical Block Address
4 Logical Block Address
5 Logical Block Address (LSB)
6 00000000
7 Transfer Byte Length (MSB)
8 Transfer Byte Length (LSB)
9 000000FlagLink
This command reads the logical data block data and its ECC byte, specified in the “Logical block
address” field in the CDB, from the disk media and transfers it to the INIT. Normally, this
command is used in combination with the WRITE LONG command to perform checks of the ECC
function. The operation object in this command is 1 data block only.
Remark T he Pad Byte and Sync Byte patterns are not included in the transfer data.
When “0” is specified in bit 1 of CDB byte 1, the “CORRCT (Corrected)” bit, the IDD d oes not
implement ECC correction processing of data read from the disk media. When “1” is specified in
the “CORRCT (Corrected)” bit, data errors that can be corr ected by ECC are transferred to the
INIT after being corrected in the IDD’s data buffer.
The "Logical byte length" field in the CDB indicates the number of bytes of data transferred to the
INIT by this command and if 1 logical data block is configured from n logical sectors (n: 1, 2, 4), it
is necessary to specify a [Logical data block lengt h + n x 44] byte length.
When the “Transfer byte length” specifies zero, this command executes a seek operation of the
cylinder/track existing in the logical data block which is specified in the “Logical block address”
field in the CDB., then is terminated without data being transferred to the INIT.
When a length (other than zero) which does not match the data format on the disk media is
specified in the “Transfer byte length” field in the CDB, this command is terminated with a
CHECK CONDITION status without executing a data transfer to the INIT. At this time, the sense
data indicate the following contents and the INIT can determine the correct “Transfer byte length”
from their contents.