Read capacity (cd-rom mode) 25h, Pre-execution checks, Command descriptor block – HP Q153090901 User Manual
Page 124: Cdb fields, Read capacity data, Read capacity, Command descriptor block: cdb fields
Commands
124
READ CAPACITY
(CD-ROM mode)
25h
R
EAD capacity
transfers Read Capacity data to the host.
Pre-execution checks:
If the drive is not in CD-ROM mode, the request will return
CHECK CONDITION
status with a sense
key Illegal Command.
Command descriptor block:
CDB fields:
Read Capacity data
The following data is always returned:
Illegal Field
Fixed Bit
Flag Link
Bad LUN
Reservation
Deferred Error
Unit Attention
7
6
5
4
3
2
1
0
0
Operation Code (25h)
1
Logical Unit Number
Reserved (0)
RelAdr(0)
2
(MSB)
Logical Block Address (0)
5
(LSB)
6
Reserved (0)
7
Reserved (0)
8
Reserved (0)
PMI
9
Control
Logical Block Address This flag is ignored. It is recommended that it should be zero.
PMI
This flag is ignored. It is recommended that it should be zero.
7
6
5
4
3
2
1
0
0
(MSB)
Returned Logical Block Address
(0004B000h)
3
(LSB)
4
(MSB)
Block Length in bytes
(00000800h)
7
(LSB)