Seagate Setting Up and Understanding Barracuda ATA Devices

4.3.1Identify 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 Table 9 on page 27. 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. See Section 2.0 on page 3 for default parameter settings.

The following commands contain drive-specific features that may not be included in the Serial ATA specifica- tion.

Word	Description	Value
	Configuration information:
	• Bit 15: 0 = ATA; 1 = ATAPI	0C5AH
0	• Bit 7: removable media
	• Bit 6: removable controller
	• Bit 0: reserved
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	x.xx
	(8 ASCII character string, padded with blanks to end of string)
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	8010H
	multiple (16)
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
59	Number of sectors transferred during a Read Multiple	xxxxH
	or Write Multiple command

Barracuda 7200.12 Serial ATA Product Manual, Rev. B 29