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4.1.11. Drive Address Register
This register is provided for compatibility with the AT disk drive interface. It is recommended
that this register not be mapped into the host's I/O space because of potential conflicts on
Bit 7. The bits are defined as follows:
D7
D6
D5
D4
D3
D2
D1
D0
X
-WTG
-HS3
-HS2
-HS1
-HS0
-nDS1
-nDS0
Bit 7
This bit is unknown.
Implementation Note:
Conflicts may occur on the host data bus when this bit is provided by a Floppy Disk Controller
operating at the same addresses as the SSD. Following are some possible solutions to
this problem:
1. Locate the SSD at a non-conflicting address (i.e., Secondary address (377) when a Floppy
Disk Controller is located at the Primary addresses).
2. Do not install a Floppy and a SSD in the system at the same time.
3. Implement a socket adapter that can be programmed to (conditionally) tri-state D7 of I/0
address 3F7/377 when a SSD product is installed and conversely to tri-state D6-D0 of
I/O address 3F7/377 when a floppy controller is installed.
4. Do not use the SSD’s Drive Address register. This may be accomplished by either a) If
possible, program the host adapter to enable only I/O addresses 1F0-1F7, 3F6 (or 170-
177, 176) to the SSD or b) if provided use an additional Primary/Secondary
configuration in the SSD that does not respond to accesses to I/O locations 3F7 and
377. With either of these implementations, the host software must not attempt to use
information in the Drive Address Register.
Bit 6 (-WTG)
This bit is 0 when a write operation is in progress, otherwise, it is 1.
Bit 5 (-HS3)
This bit is the negation of bit 3 in the Drive/Head register.
Bit 4 (-HS2)
This bit is the negation of bit 2 in the Drive/Head register.
Bit 3 (-HS1)
This bit is the negation of bit 1 in the Drive/Head register.
Bit 2 (-HS0)
This bit is the negation of bit 0 in the Drive/Head register.
Bit 1 (-nDS1)
This bit is 0 when drive 1 is active and selected.
Bit 0 (-nDS0)
This bit is 0 when the drive 0 is active and selected.
5.ATA Command Description
This section defines the ATA command set supported by the Cactus -602 Series SATA SSDs.
5.1. ATA Command Set
Table 5-7 summarizes the supported ATA command set .
Table 5-7. ATA Command Set
COMMAND
Code
FR
SC
SN
CY
DH
Check Power Mode
E5h or
98h
-
-
-
-
D
Execute Drive Diagnostic
90h
-
-
-
-
-
Flush Cache
E7h
-
-
-
-
Y
Flush Cache Ext
EAh
-
-
-
-
Y
Identify Drive
ECh
-
-
-
-
D
Cactus Technologies Limited
-602 Series Industrial Grade SATA SSD Product Manual
v1.4
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