4.1.2Identify 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 the Table 6 on page 28. 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 Draft ATA-7 Standard.

Word

Description

Value

 

 

 

 

Configuration information:

0C5AH

 

• Bit 15: 0 = ATA; 1 = ATAPI

 

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 (8 ASCII character string, padded with blanks to

x.xx

 

end of string)

 

 

 

 

27–46

Drive model number

ST3xxxxxACE

 

(40 ASCII characters, padded with blanks to end of string)

 

 

 

 

47

(Bits 7–0) Maximum sectors per interrupt on Read multiple and

8010H

 

Write 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 or Write Multi-

xxxxH

 

ple command

 

30

DB35.3 Series PATA Product Manual, Rev. C

Page 38
Image 38
Seagate ST3300820ACE, ST3250820ACE, ST3320820ACE, ST3750840ACE, ST3400820ACE Identify Device command, Word Description Value