T
T
TS
S
S3
3
32
2
2M
M
M~
~
~1
1
1G
G
GC
C
CF
F
F8
8
80
0
0
80X CompactFlash Card
Transcend Information Inc.
32
4.6 Socket and Copy Register (Base + 06h in Attribute Memory)
This register contains additional configuration information. This register is always written by the system before writing
the card’s Configuration Index Register. This register is not required for CF Cards.
If present, it is optional for a CF Card to allow setting bit D4 (Drive number) to 1. If two drives are supported, it is
intended for use only when two cards are co-located at either the primary or secondary addresses in PCMCIA I/O mode.
The availability and capabilities of this register are described in the Card Information Structure of t he CF Card.
Hosts shall not depend on the availability of this functionality.
Reserved: this bit is reserved for future standardization. This bit shall be set to zero (0) by the software when the register
is written.
Obsolete (Drive #): this bit is obsolete and should be written as 0.
If the obsolete functionality is not supported it shall be read as written or shall be read as 0. If the obsolete
functionality is supported, the bit shall be read as written. If supported, this bit sets the drive number, which the card
matches with the DRV bit of the Drive/Head register when configured in a twin card configuration.
It is recommended that the host always write 0 for the drive number in this register and in the DRV bit of the
Drive/Head register for PCMCIA modes of operation.
X: the socket number is ignored by the CompactFlash Storage Card.
4.7 I/O Transfer Function
The I/O transfer to or from the CompactFlash Storage can be either 8 or 16 bits. When a 16 bit accessible