Fujitsu MAP3147 Computer Drive User Manual


 
3.4 Maintenance, Diagnostic Commands
C141-E167
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3.4.5 READ LONG (3E)
Bit
Byte
76543210
0X3E
1LUN000
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 0000000Link
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 The 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 does 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 corrected by ECC are transferred to the INIT
after being corrected in the IDD’s data buffer.
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.
Sense Key : 05 = ILLEGAL REQUEST
Sense Code/Sub-sense Code : 24-00 = Invalid field in CDB
“VALID” Bit : “1”
“ILI” bit : “1”
Information Field : (“Transfer byte length in the CDB) – (Original “Transfer byte length”)
Remark The calculation formula for the information field expresses 1 logical data block as n
physical sectors, and when negative, as a complement of 2.