Atapi Identify Device (A1H) - Seagate STT20000A Product Manual

Chapter 5

ATAPI Identify Device (A1h)

Page 36
Issuing PIO and DMA transfer modes does not actually select these operations;
however, issuing these modes selects the rate of either type of transfer, as selected
by the DMA bit (bit 0) of the ATAPI Features register.
The protocol and timing of this command conforms to a standard ATA type
command as defined in ATA-2.
Note: This command is similar to the ATA Identify Device command except it uses
a different op-code. The ATA Identify Device command is aborted.
This command is generally intended to be used by a low-level ATAPI driver to
determine the number and type of ATA/ATAPI devices attached to the interface.
This driver might be able to program transfer rates and other parameters in the host
ATA (IDE) interface.
The following table defines the values returned by the drive.
Word Description
0 General Configuration
1-3 Disk info: cylinders, heads
4-6 Disk info: track, sector sizes
7-9 Reserved
10-19 Serial Number (20 ASCII characters)
20 Buffer Type
21 Buffer Size
22 ECC Bytes Available
23-26 Firmware Revision (8 ASCII
characters)
27-46 Model Number (40 ASCII characters)
47,48 Disk info: mult-xfer, double word I/O
49 Capabilities
50 Reserved
51 PIO Data Transfer Cycle Timing
52 DMA Data Transfer Cycle Timing
Value Meaning
81C0h ATAPI Streaming Tape, Removable
Accelerated DRQ, 12 byte packets
0000h Unsupported
0000h Unsupported
0000h —
"N...N" Serial Number
4002h Cap & Mech Sts bytes 6 and 7
02D8h 14 frames of 52 data blocks=728
0000h Unsupported
"N.NN" Firmware Revision
Model Number. "Seagate STT20000A"
0000h Unsupported
0F00h IORDY supported. Logical Blocks
Addressing and DMA supported
0000h —
0200h Mode 2
0200h Mode 2
STT20000A Product Manual
ATAPI Interface