Chapter 5
ATAPI Interface
Page 98
Seagate Travan 40 Product Manual
IDENTIFY PACKET DEVICE (ATA Command A1)
This command allows an ATAPI (not ATA) device to report its capabilities to the
Host.
The data returned are very extensive and detailed. Please refer to the ATA-4
document for complete details. Many details that are not relevant to this device have
been omitted.
The result data returned to the Host will always be 512 bytes long.
Some parameters are defined as 32-bit values (e.g., words 57 and 58). Such fields
are transferred using two word transfers. The device shall first transfer the least
significant bits, bits 15 through 0 of the value, on (bus) bits DD (15:0) respectively.
After the least significant bits have been transferred, the most significant bits, bits 31
through 16 of the value, shall be transferred on DD (15:0) respectively.
Some parameters are defined as a string of ASCII characters. For the string
“Copyright,” the character “C” is the first byte; the character “o” is the 2
nd
byte, etc.
When such fields are transferred, the order of transmission is:
1. The 1
st
character (“C”) is on bits DD (15:8) of the first word
2. The 2
nd
character (“o”) is on bits DD (7:0) of the first word
3. The 3
rd
character (“p”) is on bits DD (15:8) of the second word
4. The 4
th
character (“y”) is on bits DD (7:0) of the second word
etc.
Host Taskfile Registers—Inputs
Data Bits
Host Taskfile
Register
7
6
5
4
3
2
1
0
HEX
Features
N/A
N/A
Sector Count
N/A
N/A
Sector
Number
N/A
N/A
Byte Count
High
N/A
N/A
Byte Count
Low
N/A
N/A
Device/Head
rsvd
LBA
rsvd
DEV
SAM LUN (not used)
Command
command
A1
Summary of Contents for Travan 40
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