Maxtor 10K V - Manual (Page 154)

5-96 Maxtor Atlas 10K V
5.21 READ CAPACITY Command (25h)
The READ CAPACITY command reports formatted capacity and track-boundary
information. The data format and field descriptions are shown in Table 5-125 and
Table 5-126 respectively.
Table 5-125
READ CAPACITY Command-Data Format
Table 5-126
READ CAPACITY Command-Field Descriptions
Table 5-127 shows the READ CAPACITY Returned Data - Data Format that will
be sent during the data-in buffer transfer for the command. Refer to the PMI
description in Table 5-126 for a description of these data fields.
Table 5-127
READ CAPACITY Returned Data-Data Format
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation Code (25h)
1 Reserved RelAdr
2 - 5 Logical Block Address
6 - 7 Reserved
8 Reserved PMI
9 Control
Field Description
RelAdr Relative Addressing is not supported by the drive; the field must be 0.
Logical Block Address Used in conjunction with the PMI bit. Must be 0 when the PMI bit is 0.
PMI
Partial Media Indicator. When the value in the field is 0, the Returned Log-
ical Block Address (Table 5-127) is that of the last logical sector of the log-
ical unit.
When the value is 1, the Returned Logical Block Address is that of the last
sector on the same cylinder as the Logical Block Address supplied in the
Command Descriptor Block's LBA field. That is, the Returned Logical
Block Address is that of the Logical Block Address before a substantial de-
lay in data transfer will be encountered).
In either case, Block Length in Bytes (Table 5-127) is the unit's logical sec-
tor size, as determined by the Block Length field in the Mode parameter
Block Descriptor.
Bit
Byte
7 6 5 4 3 2 1 0
0 - 3 Returned Logical Block Address
4 - 7 Block Length in Bytes