NAS HDD Product Manual, Rev. A 29
www.seagate.com SATA Interface
4.3.1 Identify Device command

The Identify Device command (command code ECH) transfers information about the drive to the host following

power up. The data is organized as a single 512-byte block of data, whose contents are shown in on page 26. All

reserved bits or words should be set to zero. Parameters listed with an “x” are drive-specific or vary with the state

of the drive.

The following commands contain drive-specific features that may not be included in the SATA specification.

Table 8 Identify Device commands
Word Description Value
0 Configuration information:

• Bit 15: 0 = ATA; 1 = ATAPI

• Bit 7: removable media

• Bit 6: removable controller

• Bit 0: reserved

0C5AH
1 Number of logical cylinders 16,383
2 ATA-reserved 0000H
3 Number of logical heads 16
4 Retired 0000H
5 Retired 0000H
6 Number of logical sectors per logical track: 63 003FH
7–9 Retired 0000H
10–19 Serial number: (20 ASCII characters, 0000H = none) ASCII
20 Retired 0000H
21 Retired 0400H
22 Obsolete 0000H
23–26 Firmware revision
(8 ASCII character string, padded with blanks to end of
string)
x.xx
27–46 Drive model number:
(40 ASCII characters, padded with blanks to end of string)
47 (Bits 7–0) Maximum sectors per interrupt on Read multiple
and Write multiple (16)
8010H
48 Reserved 0000H
49 Standard Standby timer, IORDY supported and may be
disabled
2F00H
50 ATA-reserved 0000H
51 PIO data-transfer cycle timing mode 0200H
52 Retired 0200H
53 Words 54–58, 64–70 and 88 are valid 0007H
54 Number of current logical cylinders xxxxH
55 Number of current logical heads xxxxH
56 Number of current logical sectors per logical track xxxxH
57–58 Current capacity in sectors xxxxH